An improved synthesis, spectroscopic (FT-IR, NMR) study and DFT computational analysis (IR, NMR, UV-Vis, MEP diagrams, NBO, NLO, FMO) of the 1,5-methanoazocino[4,3-b]indole core structure

NASA Astrophysics Data System (ADS)

Uludağ, Nesimi; Serdaroğlu, Goncagül

2018-03-01

This study examines the synthesis of azocino[4,3-b]indole structure, which constitutes the tetracyclic framework of uleine, dasycarpidoneand tubifolidineas well as ABDE substructure of the strychnosalkaloid family. It has been synthesized by Fischer indolization of 2 and through the cylization of 4 by 2,3-dichlor-5-6-dicyanobenzoquinone (DDQ). 1H and 1C NMR chemical shifts have been predicted with GIAO approach and the calculated chemical shifts show very good agreement with observed shifts. FT-IR spectroscopy is important for the analysis of functional groups of synthesized compounds and we also supported FT-IR vibrational analysis with computational IR analysis. The vibrational spectral analysis was performed at B3LYP level of the theory in both the gas and the water phases and it was compared with the observed IR values for the important functional groups. The DFT calculations have been conducted to determine the most stable structure of the 1,2,3,4,5,6,7-Hexahydro-1,5-methanoazocino [4,3-b] indole (5). The Frontier Molecular Orbital Analysis, quantum chemical parameters, physicochemical properties have been predicted by using the same theory of level in both gas phase and the water phase, at 631 + g** and 6311++g** basis sets. TD- DFT calculations have been performed to predict the UV- Vis spectral analysis for this synthesized molecule. The Natural Bond Orbital (NBO) analysis have been performed at B3LYP level of theory to elucidate the intra-molecular interactions such as electron delocalization and conjugative interactions. NLO calculations were conducted to obtain the electric dipole moment and polarizability of the title compound.

Synthesis, spectral and quantum chemical studies on NO-chelating sulfamonomethoxine-cyclophosph(V)azane and its Er(III) complex.

PubMed

Alaghaz, Abdel-Nasser M A; Ammar, Reda A A; Koehler, Gottfried; Wolschann, Karl Peter; El-Gogary, Tarek M

2014-07-15

Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of novel ethane-1,2-diol-dichlorocyclophosph(V)azane of sulfamonomethoxine (L), and its binuclear Er(III) complex. Different tautomers of the ligand were optimized at the ab initio DFT level. Keto-form structure is about 15.8 kcal/mol more stable than the enol form (taking zpe correction into account). Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which show good agreement with measured electronic spectra. The structures of the novel isolated products are proposed based on elemental analyses, IR, UV-VIS, (1)H NMR, (31)P NMR, SEM, XRD spectra, effective magnetic susceptibility measurements and thermogravimetric analysis (TGA). Copyright © 2014 Elsevier B.V. All rights reserved.

Conformational analysis, UV-VIS, MESP, NLO and NMR studies of 6-methoxy-1,2,3,4-tetrahydronaphthalene.

PubMed

Arivazhagan, M; Kavitha, R; Subhasini, V P

2014-07-15

The detailed HF and B3LYP/6-311++G(d,p) comparative studies on the complete FT-IR and FT-Raman spectra of 6-methoxy-1,2,3,4-tetrahydronaphthalene [MTHN] have been studied. In view of the special properties and uses, the present investigation has been undertaken to provide a satisfactorily vibrational analysis of 6-methoxy-1,2,3,4-tetrahydronaphthalene. Therefore, a thorough Raman, IR, molecular electrostatic potential (MESP), non-linear optical (NLO) properties, UV-VIS, HOMO-LUMO and NMR spectroscopic investigation are reported complemented by B3LYP theoretical predictions with basis set 6-311++G(d,p) to provide novel insight on vibrational assignments and conformational stability of MTHN. Potential energy surface scans (PES) of the CH3 group are undertaken to shed light on the rather complicated conformational interchanges in the compound under investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

The existence of imidazoline corrosion inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, J.A.; Valone, F.W.

1985-05-01

Spectroscopic methods, i.e., Fourier transform infrared (FT-IR), carbon-13 nuclear magnetic reasonance (/sup 13/C NMR), and ultraviolet (UV) spectroscopy, were used to investigate the actual chemical composition of oilfield corrosion inhibitors. Inhibitor formulations consisting of an amide or imidazoline reacted with a dimer-trimer acid, along with an ethoxylated surfactant and an aromatic solvent, were used for these studies. /sup 13/C NMR and FT-IR spectra of these inhibitors, as well as spectra of pure imidazolines, showed that the imidazoline functional group was fairly rapidly hydrolyzed to the amide form. For instance, in FT-IR studies, the imine functional group decreased in intensity asmore » a function of time. Coincident with this was an increase in the intensities of the vibrational resonances attributed to the amide functionality. The relative molar ratio of imidazoline to amide in a corrosion inhibitor could be calculated via UV spectroscopy. Within a 20 day interval after inhibitor synthesis, this ratio decreased by a factor greater than 20. These results, as well as a discussion of their economic impact on oilfield corrosion inhibitor formulation, are presented in this paper.« less

Two new C19-diterpenoid alkaloids from Aconitum tsaii.

PubMed

Li, Gui-Qiong; Zhang, Li-Mei; Zhao, Da-Ke; Chen, Yan-Ping; Shen, Yong

2017-05-01

Two new C 19 -diterpenoid alkaloids, 14-benzoylliljestrandisine (1) and 14-anisoylliljestrandisine (2), were isolated from the roots of Aconitum tsaii. Their structures were elucidated by different spectroscopic (IR, UV, 1D and 2D NMR) and mass-spectrometric techniques.

Structural, absorption, and molecular properties of o,o'-dihydroxyazo resorcinol dyes bearing an acryloyloxy group

NASA Astrophysics Data System (ADS)

Özkınalı, Sevil; Çavuş, M. Serdar; Ceylan, Abdullah; Gür, Mahmut

2017-12-01

To the best of our knowledge, this is the first study reporting the synthesis and characterization of o,o‧-dihydroxyazo dyes bearing an acryloyl group. The o,o‧-dihydroxyazo dyes were synthesized through coupling of resorcinol with the diazonium salts of 2-amino-4-methylphenol, 2-aminophenol, 2-amino-4-chlorophenol, and 2-amino-4-nitrophenol. Their acryloyl derivatives were synthesized using metallic sodium and acryloyl chloride under an inert atmosphere. Characterization of the compounds was conducted using infrared (IR), ultraviolet-visible (UV-vis), proton nuclear magnetic resonance (1H NMR), and carbon nuclear magnetic resonance (13C NMR) spectroscopic methods. The tautomerism of the synthesized compounds' was also evaluated. The results were compared with theoretical results obtained by density functional theory (DFT). The DFT calculations were performed to obtain ground-state optimized geometries and calculate the relevant electronic and chemical reactivity parameters. Furthermore, possible tautomers deduced from the UV-vis spectra were investigated using theoretical calculations. Both the IR and NMR spectral data showed that azo tautomers predominate in the solid state and DMSO solvent. The effects of pH, solvent, and substituent on the predominant tautomers were further investigated through UV-vis spectroscopy. The results indicate that hydrazone tautomers were dominant at pH 12 in dimethylformamide (DMF), whereas azo tautomers were dominant at pH 2 in EtOH or CHCl3.

X-ray structure determination, Hirshfeld surface analysis, spectroscopic (FT-IR, NMR, UV-Vis, fluorescence), non-linear optical properties, Fukui function and chemical activity of 4‧-(2,4-dimethoxyphenyl)-2,2‧:6‧,2″-terpyridine

NASA Astrophysics Data System (ADS)

Demircioğlu, Zeynep; Yeşil, Ahmet Emin; Altun, Mehmet; Bal-Demirci, Tülay; Özdemir, Namık

2018-06-01

The compound 4‧-(2,4-dimethoxyphenyl)-2,2‧:6‧,2″-terpyridine (Mtpyr) was synthesized and investigated using X-ray single crystal structure determination, combined with Hirshfeld topology analysis of the molecular packing. In addition, Mtpyr was characterized by experimental and theoretical FT-IR, UV-Vis, 1H NMR, 13C NMR and fluorescence emission spectra. The optimized molecular geometry (bond length, bond angle, torsion angle), the complete vibrational frequency and all other theoretical computations were calculated by using density functional theory (DFT) B3LYP method with the help of 6-311++G(d,p) basis set. From the recorded UV-Vis spectrum, the electronic properties such as excitation energies, wavelength and oscillator strength are evaluated by TD-DFT in chloroform solution. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge-independent atomic orbital (GIAO) method and compared with experimental results. The calculated HOMO-LUMO band gap energies confirmed that charge transfer and chemical stability within the molecule. The hyperconjugative interaction energy E(2) and electron densities of donor (i) and acceptor (j) bonds were calculated using natural bond orbital (NBO) analysis. Besides Mulliken and natural population charges (NPA), non-linear optic properties (NLO), Fukui Function analysis, molecular electrostatic potential (MEP) were also computed which helps to identifying the electrophilic/nucleophilic nature.

Spectroscopy: An Introduction for Talented High School Students.

ERIC Educational Resources Information Center

Magyar, Elaine; Magyar, James G.

1989-01-01

Investigates the four week chemistry program in a summer program in science and mathematics. Identifies weekly topics for the program: (1) color and visible spectroscopy; (2) UV spectroscopy, fluorescence, and chemiluminescence; (3) IR and NMR spectroscopy; and (4) lists 12 individual projects. (MVL)

Spectroscopic investigations (FT-IR, UV, 1H and 13C NMR) and DFT/TD-DFT calculations of potential analgesic drug 2-[2-(dimethylamino)ethyl]-6-methoxy-4-(pyridin-2-yl)-1(2H)-phthalazinone

NASA Astrophysics Data System (ADS)

Sroczyński, Dariusz; Malinowski, Zbigniew

2017-12-01

The theoretical molecular geometry and the IR, UV, 1H and 13C NMR spectroscopic properties of 2-[2-(dimethylamino)ethyl]-6-methoxy-4-(pyridin-2-yl)-1(2H)-phthalazinone with the previously demonstrated in vivo analgesic activity were characterized. The conformational analysis, performed using the molecular mechanics method with the General AMBER Force Field (GAFF) and the Density Functional Theory (DFT) approach with the B3LYP hybrid functional and the 6-31 + g(d) basis sets, allowed to determine the most stable rotamer. The theoretical molecular geometry of this conformer was then calculated at the B3LYP/6-311++g(d,p) level of theory, and its phthalazinone core was compared with the experimental geometry of 1(2H)-phthalazinone. The calculated vibrational frequencies and the potential energy distribution enabled to assign the theoretical vibrational modes to the experimental FT-IR bands. The UV spectrum calculated with the Time-Dependent Density Functional Theory (TD-DFT) method in methanol identified the main electronic transitions and their character. 1H and 13C NMR chemical shifts simulated by the Gauge-Independent Atomic Orbital (GIAO) method in chloroform confirmed the previous assignment of the experimental resonance signals. The stability of the molecule was considered taking into account the hyperconjugation and electron density delocalization effects evaluated by the Natural Bond Orbital (NBO) method. The calculated spatial distribution of molecular electrostatic potential made possible to estimate the regions with nucleophilic and electrophilic properties. The results of the potentiodynamic polarization measurements were also indicated the corrosion inhibition activity of the title compound on 100Cr6 bearing steel in 1 mol dm-3 HCl solution.

Comparative theoretical and experimental study on novel tri-quinoline system and its anticancer studies

NASA Astrophysics Data System (ADS)

Gayathri, Kasirajan; Radhika, Ramachandran; Shankar, Ramasamy; Malathi, Mahalingam; Savithiri, Krishnaswamy; Sparkes, Hazel A.; Howard, Judith A. K.; Mohan, Palathurai Subramaniam

2017-04-01

A novel compound 2-chloro-3,6-bis-(quinolin-8-yloxymethyl)-quinoline 3 bearing a tri-quinoline moiety has been synthesized from 2-chloro-3,6-dimethyl quinoline 1 and 8-hydroxy quinoline 2 using dry acetone and K2CO3 as a base. 3 has been characterized by using FT-IR, FT-Raman, UV-Vis, 1H NMR, 13C NMR spectra and single crystal X-ray diffraction methods. We have also made a combined experimental and theoretical study on the molecular structure, vibrational spectra, NMR, FT-IR, FT-Raman and UV-Vis spectra of 2-chloro-3,6-bis-(quinolin-8-yloxymethyl)-quinoline. The theoretical studies of the title compound have been evaluated by using density functional theory calculations using B3LYP/6-31+G(d,p) and M06-2X/6-31+G(d,p) level of theories. The calculated theoretical values were found to be in good agreement with the experimental findings. The single crystal structure 3 crystallized in the orthorhombic space group Pna21. The compound 3 exhibits higher cytotoxicity in human cervical cancer cell lines (HeLa) than human breast cancer cell lines (MCF7).

Spectral and quantum chemical studies on 1,3-bis(N(1)-4-amino-6-methoxypyrimidinebenzenesulfonamide-2,2,4,4-ethane-1,2-dithiol)-2,4-dichlorocyclodiphosph(V)azane and its erbium complex.

PubMed

Al-Mogren, Muneerah M; Alaghaz, Abdel-Nasser M A; El-Gogary, Tarek M

2014-01-24

Novel 1,3-bis(N(1)-4-amino-6-methoxypyrimidine-benzenesulfonamide-2,2,4,4-ethane-1,2-dithiol)-2,4-dichlorocyclodiphosph(V)azane (L), was prepared and their coordinating behavior towards the lanthanide ion Er(III) was studied. The structures of the isolated products are proposed based on elemental analyses, IR, UV-VIS., (1)H NMR, (13)C NMR, (31)P NMR, SEM, XRD, mass spectra, effective magnetic susceptibility measurements and thermogravimetric analysis (TGA). Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of L and its binuclear Er(III) complex. Different tautomers of the ligand were optimized at the ab initio DFT level. Keto-form structure is about 17.7 kcal/mol more stable than the enol form (taking zpe correction into account). Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which compared by the measured electronic spectra. Copyright © 2013 Elsevier B.V. All rights reserved.

Aromatic hydrazones derived from nicotinic acid hydrazide as fluorimetric pH sensing molecules: Structural analysis by computational and spectroscopic methods in solid phase and in solution

NASA Astrophysics Data System (ADS)

Benković, T.; Kenđel, A.; Parlov-Vuković, J.; Kontrec, D.; Chiş, V.; Miljanić, S.; Galić, N.

2018-02-01

Structural analyses of aroylhydrazones were performed by computational and spectroscopic methods (solid state NMR, 1 and 2D NMR spectroscopy, FT-IR (ATR) spectroscopy, Raman spectroscopy, UV-Vis spectrometry and spectrofluorimetry) in solid state and in solution. The studied compounds were N‧-(2,3-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (1), N‧-(2,5-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (2), N‧-(3-chloro-2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (3), and N‧-(2-hydroxy-4-methoxyphenyl-methylidene)-3-pyridinecarbohydrazide (4). Both in solid state and in solution, all compounds were in ketoamine form (form I, sbnd COsbnd NHsbnd Ndbnd Csbnd), stabilized by intramolecular H-bond between hydroxyl proton and nitrogen atom of the Cdbnd N group. In solid state, the Cdbnd O group of 1-4 were involved in additional intermolecular H-bond between closely packed molecules. Among hydrazones studied, the chloro- and methoxy-derivatives have shown pH dependent and reversible fluorescence emission connected to deprotonation/protonation of salicylidene part of the molecules. All findings acquired by experimental methods (NMR, IR, Raman, and UV-Vis spectra) were in excellent agreement with those obtained by computational methods.

Synthesis, spectroscopic (UV-Vis, FT-IR and NMR), single crystal XRD of 3,5-diethyl -2,6-di(thiophen-2-yl)piperidin-4-on-1-ium picrate: A comprehensive experimental and computational study

NASA Astrophysics Data System (ADS)

Arockia doss, M.; Rajarajan, G.; Thanikachalam, V.; Selvanayagam, S.; Sridhar, B.

2017-01-01

A piperidin-4-one containing picrate 3,5-diethyl -2,6-di(thiophen-2-yl)piperidin-4-on-1-ium picrate [3,5-DPPP] was synthesized. The molecular structure of 3,5-DPPP was confirmed by FT-IR, NMR, Uv-Vis, single crystal XRD analysis and DFT and HF methods with 6-31G(d,p) basis set. The XRD data confirm the transfer of protons from picric acid (O2) to piperidin-4-one ring (N1). The 3,5-DPPP compound is stabilized by the presence of intermolecular and intramolecular hydrogen bonds (N-H⋯O, C-H⋯S and C-H⋯O). Density functional theory and HF calculations have been used widely for calculating a wide variety of molecular properties such as optimized structure, FT-IR and Uv-Vis spectra, and provided reliable results which are in agreement with experimental data. The charge density data have been used to understand the properties of molecular systems. Furthermore, several quantum chemical insights have been obtained in the form of the total and partial density of states, the HOMO-LUMO energy gap and electrostatic potential map etc. In addition, the polarizability and first hyperpolarizability were calculated to show the potential applications of 3,5-DPPP in nonlinear optics.

De novo design of chiral organotin cancer drug candidates: validation of enantiopreferential binding to molecular target DNA and 5'-GMP by UV-visible, fluorescence, (1)H and (31)P NMR.

PubMed

Arjmand, Farukh; Sharma, Girish Chandra; Sayeed, Fatima; Muddassir, Mohd; Tabassum, Sartaj

2011-12-02

N,N-bis[(R-/S-)-1-benzyl-2-ethoxyethane] tin (IV) complexes were synthesized by applying de novo design strategy by the condensation reaction of (R-/S-)2-amino-2-phenylethanol and dibromoethane in presence of dimethyltin dichloride and thoroughly characterized by elemental analysis, conductivity measurements, IR, ESI-MS, (1)H, (13)C and (119)Sn, multinuclear NMR spectroscopy and XRD study. Enantioselective and specific binding profile of R-enantiomer 1 in comparison to S-enantiomer 2 with ultimate molecular target CT-DNA was validated by UV-visible, fluorescence, circular dichroism, (1)H and (31)P NMR techniques. This was further corroborated well by interaction of 1 and 2 with 5'-GMP. Copyright © 2011 Elsevier B.V. All rights reserved.

Three new alkaloids from the fruits of Morus alba.

PubMed

Wang, Xin; Kang, Jie; Wang, Hong-Qing; Liu, Chao; Li, Bao-Ming; Chen, Ruo-Yun

2014-01-01

From the fruits of Morus alba, three new alkaloids, mulbaines A (1), B (2), and C (3) were isolated. The structures of these compounds were elucidated on the basis of spectroscopic methods (UV, IR, HR-ESI-MS, 1D, and 2D NMR).

Anti-inflammatory drugs interacting with Zn (II) metal ion based on thiocyanate and azide ligands: synthesis, spectroscopic studies, DFT calculations and antibacterial assays.

PubMed

Chiniforoshan, Hossein; Tabrizi, Leila; Hadizade, Morteza; Sabzalian, Mohammad R; Chermahini, Alireza Najafi; Rezapour, Mehdi

2014-07-15

Zinc (II) complexes with non-steroidal anti-inflammatory drugs (NSAIDs) naproxen (nap) and ibuprofen (ibu) were synthesized in the presence of nitrogen donor ligands (thiocyanate or azide). The complexes were characterized by elemental analysis, FT-IR, (1)H NMR and UV-Vis spectroscopes. The binding modes of the ligands in complexes were established by means of molecular modeling of the complexes, and calculation of their IR, NMR and absorption spectra at DFT (TDDFT)/B3LYP level were studied. The experimental and calculated data verified monodentate binding through the carboxylic oxygen atoms of anti-inflammatory drugs in the zinc complexes. The calculated (1)H, FT-IR and UV-Vis data are in better agreement with the experimental results, and confirm the predicted tetrahedral structures for the Zn (II) complexes. In addition to DFT calculations of complexes, natural bond orbital (NBO) was performed at B3LYP/6-31+G(d,p) level of theory. Biological studies showed the antibacterial activity of zinc complexes against Gram-positive and Gram-negative bacterial strains. Copyright © 2014 Elsevier B.V. All rights reserved.

First identification and quantification of lorcaserin in an herbal slimming dietary supplement.

PubMed

Hachem, Rabab; Malet-Martino, Myriam; Gilard, Véronique

2014-09-01

The weight-loss drug lorcaserin, a FDA approved anorectic drug, was isolated from the dietary supplement "Lose quickly" claimed to be a pure natural fast slimming diet pill. After its purification by means of preparative liquid chromatography, its structure was characterized using LC-UV, NMR, MS, MS/MS, and IR spectroscopy. The amount of lorcaserin measured by qNMR was 6.6mg/capsule. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

PubMed

Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

2014-10-15

Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

Conformational analysis, spectroscopic study (FT-IR, FT-Raman, UV, 1H and 13C NMR), molecular orbital energy and NLO properties of 5-iodosalicylic acid

NASA Astrophysics Data System (ADS)

Karaca, Caglar; Atac, Ahmet; Karabacak, Mehmet

2015-02-01

In this study, 5-iodosalicylic acid (5-ISA, C7H5IO3) is structurally characterized by FT-IR, FT-Raman, NMR and UV spectroscopies. There are eight conformers, Cn, n = 1-8 for this molecule therefore the molecular geometry for these eight conformers in the ground state are calculated by using the ab-initio density functional theory (DFT) B3LYP method approach with the aug-cc-pVDZ-PP basis set for iodine and the aug-cc-pVDZ basis set for the other elements. The computational results identified that the most stable conformer of 5-ISA is the C1 form. The vibrational spectra are calculated DFT method invoking the same basis sets and fundamental vibrations are assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method with PQS program. Total density of state (TDOS) and partial density of state (PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis for C1 conformer were calculated using the same method. The energy and oscillator strength are calculated by time-dependent density functional theory (TD-DFT) results complement with the experimental findings. Besides, charge transfer occurring in the molecule between HOMO and LUMO energies, frontier energy gap, molecular electrostatic potential (MEP) are calculated and presented. The NMR chemical shifts (1H and 13C) spectra are recorded and calculated using the gauge independent atomic orbital (GIAO) method. Mulliken atomic charges of the title molecule are also calculated, interpreted and compared with salicylic acid. The optimized bond lengths, bond angles and calculated NMR and UV, vibrational wavenumbers showed the best agreement with the experimental results.

DFT calculations and experimental FT-IR, FT-Raman, NMR, UV-Vis spectral studies of 3-fluorophenylboronic acid

NASA Astrophysics Data System (ADS)

Karabacak, M.; Kose, E.; Sas, E. B.; Kurt, M.; Asiri, A. M.; Atac, A.

2015-02-01

The spectroscopic (FT-IR, FT-Raman, 1H and 13C NMR, UV-Vis), structural, electronic and thermodynamical properties of 3-fluorophenylboronic acid (C6H4FB(OH)2), 3FPBA) were submitted by using both experimental techniques and theoretical methods (quantum chemical calculations) in this work. The experimental infrared and Raman spectra were obtained in the region 4000-400 cm-1 and 3500-10 cm-1, respectively. The equilibrium geometry and vibrational spectra were calculated by using DFT (B3LYP) with 6-311++G(d,p) basis set. The vibrational wavenumbers were also corrected with scale factor to take better results for the calculated data. The total energy distributions (TED) of the vibrational modes were performed for the assignments of the title molecule by using scaled quantum mechanics (SQM) method. The NMR chemical shifts (1H and 13C) were recorded in DMSO solution. The 1H and 13C NMR spectra were computed by using the gauge-invariant atomic orbital (GIAO) method, showing a good agreement with the experimental ones. The last one UV-Vis absorption spectra were analyzed in two solvents (ethanol and water), saved in the range of 200-400 nm. In addition these, HOMO and LUMO energies, the excitation energies, density of states (DOS) diagrams, thermodynamical properties and molecular electrostatic potential surface (MEPs) were presented. Nonlinear optical (NLO) properties and thermodynamic features were performed. The experimental results are combined with the theoretical calculations using DFT calculations to fortification of the paper. At the end of this work, the results were proved our paper had been indispensable for the literature backing.

FT-IR, FT-Raman, UV-visible, and NMR spectroscopy and vibrational properties of the labdane-type diterpene 13-epi-sclareol.

PubMed

Chain, Fernando E; Leyton, Patricio; Paipa, Carolina; Fortuna, Mario; Brandán, Silvia A

2015-03-05

In this work, FT-IR, FT-Raman, UV-Visible and NMR spectroscopies and density functional theory (DFT) calculations were employed to study the structural and vibrational properties of the labdane-type diterpene 13-epi-sclareol using the hybrid B3LYP method together with the 6-31G(∗) basis set. Three stable structures with minimum energy found on the potential energy curves (PES) were optimized, and the corresponding molecular electrostatic potentials, atomic charges, bond orders, stabilization energies and topological properties were computed at the same approximation level. The complete assignment of the bands observed in the vibrational spectrum of 13-epi-sclareol was performed taking into account the internal symmetry coordinates for the three structures using the scaled quantum mechanical force field (SQMFF) methodology at the same level of theory. In addition, the force constants were calculated and compared with those reported in the literature for similar compounds. The predicted vibrational spectrum and the calculated (1)H NMR and (13)C NMR chemical shifts are in good agreement with the corresponding experimental results. The theoretical UV-Vis spectra for the most stable structure of 13-epi-sclareol demonstrate a better correlation with the corresponding experimental spectrum. The study of the three conformers by means of the theory of atoms in molecules (AIM) revealed different H bond interactions and a strong dependence of the interactions on the distance between the involved atoms. Furthermore, the natural bond orbital (NBO) calculations showed the characteristics of the electronic delocalization for the two six-membered rings with chair conformations. Copyright © 2014 Elsevier B.V. All rights reserved.

DFT calculations and experimental FT-IR, FT-Raman, NMR, UV-Vis spectral studies of 3-fluorophenylboronic acid.

PubMed

Karabacak, M; Kose, E; Sas, E B; Kurt, M; Asiri, A M; Atac, A

2015-02-05

The spectroscopic (FT-IR, FT-Raman, (1)H and (13)C NMR, UV-Vis), structural, electronic and thermodynamical properties of 3-fluorophenylboronic acid (C6H4FB(OH)2), 3FPBA) were submitted by using both experimental techniques and theoretical methods (quantum chemical calculations) in this work. The experimental infrared and Raman spectra were obtained in the region 4000-400 cm(-1) and 3500-10 cm(-1), respectively. The equilibrium geometry and vibrational spectra were calculated by using DFT (B3LYP) with 6-311++G(d,p) basis set. The vibrational wavenumbers were also corrected with scale factor to take better results for the calculated data. The total energy distributions (TED) of the vibrational modes were performed for the assignments of the title molecule by using scaled quantum mechanics (SQM) method. The NMR chemical shifts ((1)H and (13)C) were recorded in DMSO solution. The (1)H and (13)C NMR spectra were computed by using the gauge-invariant atomic orbital (GIAO) method, showing a good agreement with the experimental ones. The last one UV-Vis absorption spectra were analyzed in two solvents (ethanol and water), saved in the range of 200-400 nm. In addition these, HOMO and LUMO energies, the excitation energies, density of states (DOS) diagrams, thermodynamical properties and molecular electrostatic potential surface (MEPs) were presented. Nonlinear optical (NLO) properties and thermodynamic features were performed. The experimental results are combined with the theoretical calculations using DFT calculations to fortification of the paper. At the end of this work, the results were proved our paper had been indispensable for the literature backing. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of polymethoxylated flavones from green tangerine peel (Pericarpium Citri Reticulatae Viride) by chromatographic and spectroscopic techniques.

PubMed

Wang, Dandan; Wang, Jian; Huang, Xuehui; Tu, Ying; Ni, Kunyi

2007-05-09

Polymethoxylated flavones (PMFs) were extracted from Pericarpium Citri Reticulatae Viride using a procedure that obtained a consistent mixture of PMFs both in identity and proportion. The mixture consisted of isosinensetin (0.2%) (1), sinensetin (1.7%) (4), tetramethyl-o-isoscutellarein (0.3%) (5), nobiletin (40.5%) (6), tetramethyl-o-scutellarein (1.2%) (7), tangeretin (45.6%) (10), 5-demethylnobiletin (8.7%) (12), 5-demethyl tangeretin (0.8%) (14) and other flavonoids including heptamethoxyflavone (1.0%) (9), among which, compounds 1, 4, 5, 7 and 9 were identified based on their UV spectra, MS data and elution order described in the literature while compounds 6, 10, 12 and 14 were isolated and identified by UV, IR, MS, (1)H NMR, (13)C NMR and 2D NMR spectral studies. In addition, compound 14 was isolated and identified for the first time from Citrus.

iSpec: A Web-Based Activity for Spectroscopy Teaching

ERIC Educational Resources Information Center

Vosegaard, Thomas

2018-01-01

Students' skills in structure elucidation of organic molecules are developed by training them to understand advanced spectroscopic measurements and elucidate structures of small organic molecules from mass spectrometry (MS) and infrared (IR), ultraviolet (UV), and [superscript 1]H and [superscript 13]C nuclear magnetic resonance (NMR)…

Cobalt(II) and Cobalt(III) Coordination Compounds.

ERIC Educational Resources Information Center

Thomas, Nicholas C.; And Others

1989-01-01

Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

Two new compounds from an endophytic fungus Pestalotiopsis heterocornis.

PubMed

Xing, Jian-Guang; Deng, Hui-Ying; Luo, Du-Qiang

2011-12-01

Two new compounds, 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-α-L-rhamnosyl-phthalide and 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-β-D-glucopyranosyl-phthalide, along with one known and related metabolite 7-hydroxy-5-methoxy-4,6-dimethylphthalide were isolated from the EtOAc extract of fermentation broth of an endophytic fungus Pestalotiopsis heterocornis. The structures of these compounds were elucidated on the basis of spectroscopic methods (UV, IR, HR-ESI-MS, 1D NMR, and 2D NMR).

Solvent effect in implicit/explicit model on FT-IR, 1H, 13C and 19F NMR, UV-vis and fluorescence spectra, linear, second- and third-nonlinear optical parameters of 2-(trifluoromethyl)benzoic acid: Experimental and computational study

NASA Astrophysics Data System (ADS)

Avcı, Davut; Altürk, Sümeyye; Tamer, Ömer; Kuşbazoğlu, Mustafa; Atalay, Yusuf

2017-09-01

FT-IR, 1H, 13C and 19F NMR, UV-vis and fluorescence spectra for 2-(trifluoromethyl)benzoic acid (2-TFMBA) were recorded. DFT//B3LYP/6-31++G(d,p) calculations were used to determine the optimized molecular geometry, vibrational frequencies, 1H, 13C and 19F GIAO-NMR chemical shifts of 2-TFMBA. The detailed assignments of vibrational frequencies were carried out on the basis of potential energy distribution (PED) by using VEDA program. TD-DFT/B3LYP/6-31++G(d,p) calculations with the PCM (polarizable continuum model) in ethanol and DMSO solvents based on implicit/explicit model and gas phase in the excited state were employed to investigate UV-vis absorption and fluorescence emission wavelengths. The UV-vis and emission spectra were given in ethanol and DMSO solvents, and the major contributions to the electronic transitions were obtained. In addition, the NLO parameters (β, γ and χ(3)) and frontier molecular orbital energies of 2-TFMBA were calculated by using B3LYP/6-31++G(d,p) level. The NLO parameters of 2-TFMBA were compared with that of para-Nitroaniline (pNA) and urea which are the typical NLO materials. The refractive index (n) is calculated by using the Lorentz-Lorenz equation to observe polarization behavior of 2-TFMBA in DMSO and ethanol solvents. In order to investigate intramolecular and hydrogen bonding interactions, NBO calculations were also performed by the same level. To sum up, considering the well-known biological role, photochemical properties of 2-TFMBA were discussed.

[The UV-Vis spectra and substituent effect of organoimido derivatives of polyoxometalates].

PubMed

Li, Qiang; Wei, Yong-ge; Wang, Yuan; Guo, Hong-you

2005-06-01

In the presence of a carbodiimine, i.e. DCC, a series of organoimido derivatives of polyoxometalates have been synthesized via the reaction of [alpha-Mo8O26]4- with aromatic amines and its hydrochloride salt. Elemental analysis, IR, 1H-NMR and UV-Vis spectra were used to characterize those hybrids, in particular their UV-Vis spectra have been studied. The results show that typical metal-ligand charge transfer (MLCT) transitions occur in the organic-inorganic hybrid molecules. There is a good linear relationship between the shift of UV-Vis absorptions (delta lamda max) and conjugation effect of the p-substituted group (sigmaR).

Structure elucidation of organic compounds aided by the computer program system SCANNET

NASA Astrophysics Data System (ADS)

Guzowska-Swider, B.; Hippe, Z. S.

1992-12-01

Recognition of chemical structure is a very important problem currently solved by molecular spectroscopy, particularly IR, UV, NMR and Raman spectroscopy, and mass spectrometry. Nowadays, solution of the problem is frequently aided by the computer. SCANNET is a computer program system for structure elucidation of organic compounds, developed by our group. The structure recognition of an unknown substance is made by comparing its spectrum with successive reference spectra of standard compounds, i.e. chemical compounds of known chemical structure, stored in a spectral database. The computer program system SCANNET consists of six different spectral databases for following the analytical methods: IR, UV, 13C-NMR, 1H-NMR and Raman spectroscopy, and mass spectrometry. A chemist, to elucidate a structure, can use one of these spectral methods or a combination of them and search the appropriate databases. As the result of searching each spectral database, the user obtains a list of chemical substances whose spectra are identical and/or similar to the spectrum input into the computer. The final information obtained from searching the spectral databases is in the form of a list of chemical substances having all the examined spectra, for each type of spectroscopy, identical or simlar to those of the unknown compound.

Experimental (FT-IR, NMR and UV) and theoretical (M06-2X and DFT) investigation, and frequency estimation analyses on (E)-3-(4-bromo-5-methylthiophen-2-yl)acrylonitrile

NASA Astrophysics Data System (ADS)

Sert, Yusuf; Balakit, Asim A.; Öztürk, Nuri; Ucun, Fatih; El-Hiti, Gamal A.

2014-10-01

The spectroscopic properties of (E)-3-(4-bromo-5-methylthiophen-2-yl)acrylonitrile have been investigated by FT-IR, UV, 1H and 13C NMR techniques. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and DFT/M06-2X (the highly parameterized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been carried out by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies were in good agreement with the corresponding experimental data, and with the results in the literature. 1H and 13C NMR chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strength wavelengths were performed by B3LYP methods. In addition, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and the other related molecular energy values have been calculated and depicted.

Spectroscopic (vibrational, NMR and UV-vis.) and quantum chemical investigations on 4-hexyloxy-3-methoxybenzaldehyde.

PubMed

Abbas, Ashgar; Gökce, Halil; Bahçeli, Semiha

2016-01-05

In this study, the 4-hexyloxy-3-methoxybenzaldehyde compound as one of the derivatives of vanillin which is a well known flavoring agent, C14H20O3, has been investigated by experimentally and extensively utilizing density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. In this context, the optimized geometry, vibrational frequencies, (1)H and (13)C NMR chemical shifts, UV-vis. (in gas phase and in methanol solvent) spectra, HOMO-LUMO analysis, molecular electrostatic potential (MEP), thermodynamic parameters and atomic charges of 4-hexyloxy-3-methoxybenzaldehyde have been calculated. In addition, theoretically predicted IR, Raman and UV-vis. (in gas phase and in methanol solvent) spectra of the mentioned molecule have been constructed. The results calculated were compared with the experimental data. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis, structural characterization and tautomeric properties of some novel bis-azo dyes derived from 5-arylidene-2,4-thiazolidinone

NASA Astrophysics Data System (ADS)

Mohammadi, Asadollah; Safarnejad, Mastaneh

Nine new bis-azo dyes derived from 5-arylidene-2,4-thiazolidinone have been synthesized in two steps using Knoevenagel condensation and diazotization-coupling reaction. The structures of the compounds were confirmed by UV-vis, IR, 1H NMR and 13C NMR spectroscopic techniques. The spectral characterizations demonstrate that there is an equilibrium between the azo (T1) and hydrazine (T2 and T3) tautomers for all prepared dyes in solutions. In addition, the solvatochromic behavior of the prepared dyes was evaluated using polarity/polarizability parameter (π*) in various solvents. The UV-vis absorption spectra of dyes show a bathochromic shift with increasing polarity and base strength of the solvents. Finally, the effects of acid and base on the UV-vis absorption spectra of the dyes with different substituent in diazo component are reported.

Monomeric and dimeric structures analysis and spectroscopic characterization of 3,5-difluorophenylboronic acid with experimental (FT-IR, FT-Raman, 1H and 13C NMR, UV) techniques and quantum chemical calculations

NASA Astrophysics Data System (ADS)

Karabacak, Mehmet; Kose, Etem; Atac, Ahmet; Asiri, Abdullah M.; Kurt, Mustafa

2014-01-01

The spectroscopic properties of 3,5-difluorophenylboronic acid (3,5-DFPBA, C6H3F2B(OH)2) were investigated by FT-IR, FT-Raman UV-Vis, 1H and 13C NMR spectroscopic techniques. FT-IR (4000-400 cm-1) and FT-Raman spectra (3500-10 cm-1) in the solid phase and 1H and 13C NMR spectra in DMSO solution were recorded. The UV spectra that dissolved in ethanol and water were recorded in the range of 200-400 nm for each solution. The structural and spectroscopic data of the molecule have been obtained for possible three conformers from DFT (B3LYP) with 6-311++G(d,p) basis set calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. Hydrogen-bonded dimer of title molecule, optimized by counterpoise correction, was also studied B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H⋯O hydrogen bonding have been discussed. 1H and 13C NMR chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT) results complements with the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were presented. The effects due to the substitutions of boric acid group and halogen were investigated. The results of the calculations were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP), nonlinear optical properties (NLO) and thermodynamic features were performed.

Spectroscopic characteristic (FT-IR, FT-Raman, UV, 1H and 13C NMR), theoretical calculations and biological activity of alkali metal homovanillates

NASA Astrophysics Data System (ADS)

Samsonowicz, M.; Kowczyk-Sadowy, M.; Piekut, J.; Regulska, E.; Lewandowski, W.

2016-04-01

The structural and vibrational properties of lithium, sodium, potassium, rubidium and cesium homovanillates were investigated in this paper. Supplementary molecular spectroscopic methods such as: FT-IR, FT-Raman in the solid phase, UV and NMR were applied. The geometrical parameters and energies were obtained from density functional theory (DFT) B3LYP method with 6-311++G** basis set calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned. Geometric and magnetic aromaticity indices, atomic charges, dipole moments, HOMO and LUMO energies were also calculated. The microbial activity of investigated compounds was tested against Bacillus subtilis (BS), Pseudomonas aeruginosa (PA), Escherichia coli (EC), Staphylococcus aureus (SA) and Candida albicans (CA). The relationship between the molecular structure of tested compounds and their antimicrobial activity was studied. The principal component analysis (PCA) was applied in order to attempt to distinguish the biological activities of these compounds according to selected band wavenumbers. Obtained data show that the FT-IR spectra can be a rapid and reliable analytical tool and a good source of information for the quantitative analysis of the relationship between the molecular structure of the compound and its biological activity.

FTIR, FT-Raman, FT-NMR, UV-visible and quantum chemical investigations of 2-amino-4-methylbenzothiazole.

PubMed

Arjunan, V; Sakiladevi, S; Rani, T; Mythili, C V; Mohan, S

2012-03-01

The FT-IR (4000-400 cm(-1)) and FT-Raman (4000-100 cm(-1)) spectral measurements and complete assignments of the observed spectra of 2-amino-4-methylbenzothiazole (2A4MBT) have been proposed. Ab initio and DFT calculations have been performed and the structural parameters of the compound were determined from the optimised geometry with 6-31G(d,p), 6-311++G(d,p) and cc-pVDZ basis sets and giving energies, harmonic vibrational frequencies, depolarisation ratios, IR intensities and Raman activities. (1)H and (13)C NMR spectra were recorded and (1)H and (13)C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO, LUMO and band gap energies were measured by time-dependent DFT (TD-DFT) approach. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman activities chemical shifts and absorption wavelengths were compared with the available experimental data of the molecule. The influences of methyl and amino groups on the skeletal modes and on the proton chemical shifts have been investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

New asymmetric and symmetric 2-((pyridin-4-yl)methylenamino)-3 aminomaleo nitrile and 2,3-bis((pyridin-4-yl)methylenamino)maleonitrile Schiff bases: Synthesis, experimental characterization along with theoretical studies

NASA Astrophysics Data System (ADS)

Zare, Nahid; Zabardasti, Abedien; Dusek, Michal; Eigner, Vaclav

2018-07-01

Two novel Schiff bases 2-((pyridin-4-yl)methelenamino)-3-aminomaleonitrile (L1) and 2,3-bis((pyridin-yl)methylenamino)maleonitrile (L2) were synthesized by the condensation of 2,3-diaminomaleonitrile and 4-pyridine carboxaldehyde using the reflux in absolute methanol. The light yellow crystalline precipitates of L1 were used for single-crystal X-ray crystallography. Two ligans L1 and L2 were characterized by UV-Vis, FT-IR and 1H/13C NMR spectroscopy. Also the FT-IR, 1H NMR and 13C NMR spectra of the compounds were calculated at the B3LYP/6-31 + G(d) level of theory. The Schiff base L1 with unit cell parameters: a = 19.8380(9), b = 4.7221(2), c = 12.9703(6) Å, V = 1215.02(9) Å3, Z = 4 crystallizes in the orthorhombic crystal system with space group Pna21. The crystal structure was solved by charge flipping using single crystal X-ray diffraction data collected at 120 K. For both ligands, the experimentally obtained NMR and IR spectra were a good agreement with their calculated counterparts.

Chemical groups and structural characterization of lignin via thiol-mediated demethylation

Treesearch

Lihong Hu; Hui Pan; Yonghong Zhou; Chung-Yun Hse; Chengguo Liu; Baofang Zhang; Bin Xu

2014-01-01

A new approach to increase the reactivity of lignin by thiol-mediated demethylation was investigated in this study. Demethylated lignin was characterized by the changes in its hydroxyl and methoxyl groups, molecular weight, and other properties using titration and spectroscopy methods including FT-IR, 1H NMR, UV,and GPC. The total...

Molecular structure and spectroscopic characterization of Carbamazepine with experimental techniques and DFT quantum chemical calculations

NASA Astrophysics Data System (ADS)

Suhasini, M.; Sailatha, E.; Gunasekaran, S.; Ramkumaar, G. R.

2015-04-01

A systematic vibrational spectroscopic assignment and analysis of Carbamazepine has been carried out by using FT-IR, FT-Raman and UV spectral data. The vibrational analysis were aided by electronic structure calculations - ab initio (RHF) and hybrid density functional methods (B3LYP) performed with standard basis set 6-31G(d,p). Molecular equilibrium geometries, electronic energies, natural bond order analysis, harmonic vibrational frequencies and IR intensities have been computed. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED) by VEDA program. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λmax were determined by HF/6-311++G(d,p) Time-Dependent method. The thermodynamic functions of the title molecule were also performed using the RHF and DFT methods. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of Carbamazepine.

Theoretical study on Curcumin: A comparison of calculated spectroscopic properties with NMR, UV vis and IR experimental data

NASA Astrophysics Data System (ADS)

Benassi, Rois; Ferrari, Erika; Lazzari, Sandra; Spagnolo, Ferdinando; Saladini, Monica

2008-12-01

The main target of this study is a high-level computational analysis of Curcumin, employing DFT approach with two different sets of basis functions (B3LYP/6-31G ∗ and B3LYP/6-311G ∗∗). Accurate quantum mechanical studies, both in vacuum and in methanol medium, are carried out with the aim to analyze the conformational equilibria, to find the most stable equilibrium structure and to define the nature of the molecular orbitals, fundamental to explain Curcumin binding characteristic. Our theoretical calculations, performed at B3LYP/6-31G ∗ and B3LYP/6-311G ∗∗ levels both in vacuum and in methanol medium, confirm that the keto-enolic forms are more stable than the di-keto one, whose extremely low population suggests that this structure should not influence Curcumin properties. Keto-enolic form C results the most stable, independently on calculation level and solvent (methanol) effect. HOMO and LUMO molecular orbitals are calculated for all the structures with the two sets of basis with very similar results. MEPs show that the negative charge is localized on the oxygen atoms, which, in the keto-enolic forms, point in the same direction enabling metal coordination. NMR, UV-vis and FT-IR experimental data are employed in the comparison with electronic and conformational properties of Curcumin resulting from theoretical calculations. The two different calculation levels (B3LYP/6-31G ∗ and B3LYP/6-311G ∗∗) give very similar results. Good linear correlations between the experimental 1H and 13C NMR chemical shifts ( δexp), in methanol- d4 (MeOD) and DMSO- d6 (DMSO), and calculated magnetic isotropic shielding tensors ( σcalc) are found ( δexp = a · σcalc + b). A good prediction of UV-vis experimental maximum absorption ( λmax) on the basis of conformer populations is obtained. A linear relation with a good correlation coefficient is observed plotting the FT-IR experimental wavenumbers vs . the calculated ones, allowing to predict FT-IR spectra.

Structural and spectroscopic (UV-Vis, IR, Raman, and NMR) characteristics of anisaldehydes that are flavoring food additives: A density functional study in comparison with experiments

NASA Astrophysics Data System (ADS)

Altun, Ahmet; Swesi, O. A. A.; Alhatab, B. S. S.

2017-01-01

The molecular structures, vibrational spectra (IR and Raman), electronic spectra (UV-Vis and DOS), and NMR spectra (13C and 1H) of p-anisaldehyde, m-anisaldehyde, and o-anisaldehyde have been studied by using the B3LYP density functional and the 6-311++G** basis set. While p-anisaldehyde has been found to contain two stable conformers at room temperature, m-anisaldehyde and o-anisaldehyde contain four stable conformers. In agreement with the calculated ground-state energetics and small transition barriers, the comparison of the experimental and calculated spectra of the anisaldehydes indicates equilibrium between all conformers at room temperature. However, the two conformers of o-anisaldehyde, in which the methoxy group lies out of the ring plane, are too rare at the equilibrium. The equilibrium conditions of the conformers of the anisaldehyde isomers have been shown readily accessible through UV-Vis and 13C NMR spectral studies but requiring very detailed vibrational analyses. The effect of the solvent has been found to red-shift the electronic absorption bands and to make the anisaldehydes more reactive and soft. Molecular electrostatic potential maps of the anisaldehydes show that their oxygen atoms are the sites for nucleophilic reactivity. Compared with the most sophisticated NBO method, ESP charges have been found mostly reliable while Mulliken charges fail badly with the present large 6-311++G** basis set. The present calculations reproduce not only the experimental spectral characteristics of the anisaldehydes but also reveal their several structural features.

UV-vis, IR and 1H NMR spectroscopic studies of some mono- and bis-azo-compounds based on 2,7-dihydroxynaphthalene and aniline derivatives

NASA Astrophysics Data System (ADS)

Issa, Raafat M.; Fayed, Tarek A.; Awad, Mohammed K.; El-Kony, Sanaa M.

2005-12-01

The absorption spectra of mono- and bis-azo-derivatives obtained by coupling the diazonium salts of aromatic amines and 2,7-dihydroxynaphthalene have been studied in six organic solvents. The different absorption bands have been assigned and the effect of solvents on the charge transfer band is also discussed. The diagnostic IR spectral bands and 1H NMR signals are assigned and discussed in relation to molecular structure. Also, semi-empirical molecular orbital calculations using the atom superposition and electron delocalization molecular orbital (ASED-MO) theory have been performed to investigate the molecular and electronic structures of these compounds. According to these calculations, an intramolecular hydrogen bonding is essential for stabilization of such molecules.

Phytochemical investigation and hair growth studies on the rhizomes of Nardostachys jatamansi DC

PubMed Central

Gottumukkala, Venkateswara Rao; Annamalai, Tiruganasambandham; Mukhopadhyay, Triptikumar

2011-01-01

Nardostachys jatamansi DC rhizomes were subjected to extraction, fractionation, and isolation of terpenoid compounds. Three terpenoid compounds were isolated which are nardal, jatamansic acid, and nardin. These compounds were identified based on physical and spectral data (UV, IR,1H and13C NMR, 2D NMR, Mass) and comparison with authentic compounds. The crude extract, fractions, and two of the isolated compounds were tested for their hair growth activity. The hair growth studies showed good activities for the extract, fraction, and the isolated compounds. PMID:21716625

Experimental and DFT studies of (E)-2-[2-(2,6-dichlorophenyl)ethenyl]-8-hydroxyquinoline: electronic and vibrational properties.

PubMed

Sun, Wenqi; Yuan, Guozan; Liu, Jingxin; Ma, Li; Liu, Chengbu

2013-04-01

The title molecule (E)-2-[2-(2,6-dichlorophenyl)ethenyl]-8-hydroxyquinoline (DPEQ) was synthesized and characterized by FT-IR, UV-vis, NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the compound in the ground state have been calculated by using the density functional theory (DFT) method. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. The calculated results indicate that the theoretical vibrational frequencies, 1H and 13C NMR chemical shift values show good agreement with experimental data. The electronic properties like UV-vis spectral analysis and HOMO-LUMO analysis of DPEQ have been reported and compared with experimental data. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron density isosurface with molecular electrostatic potential (MEP). Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental and DFT studies of (E)-2-[2-(2,6-dichlorophenyl)ethenyl]-8-hydroxyquinoline: Electronic and vibrational properties

NASA Astrophysics Data System (ADS)

Sun, Wenqi; Yuan, Guozan; Liu, Jingxin; Ma, Li; Liu, Chengbu

2013-04-01

The title molecule (E)-2-[2-(2,6-dichlorophenyl)ethenyl]-8-hydroxyquinoline (DPEQ) was synthesized and characterized by FT-IR, UV-vis, NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the compound in the ground state have been calculated by using the density functional theory (DFT) method. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. The calculated results indicate that the theoretical vibrational frequencies, 1H and 13C NMR chemical shift values show good agreement with experimental data. The electronic properties like UV-vis spectral analysis and HOMO-LUMO analysis of DPEQ have been reported and compared with experimental data. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron density isosurface with molecular electrostatic potential (MEP).

FT-IR, FT-Raman, UV, NMR spectra and molecular structure investigation of (E)-2-(3-chloropyrazin-2-yl)-1-(3-ethyl-2, 6-diphenyl piperidin-4-ylidene) hydrazine: A combined experimental and theoretical study

NASA Astrophysics Data System (ADS)

Therasa Alphonsa, A.; Loganathan, C.; Athavan Alias Anand, S.; Kabilan, S.

2015-11-01

This work presents the characterization of (E)-2-(3-chloropyrazin-2-yl)-1-(3-ethyl-2, 6-diphenyl piperidin-4-ylidene) hydrazine (HDE) by quantum chemical calculations and spectral techniques. The structure was investigated by FT-IR, FT-Raman, UV-vis and NMR techniques. The geometrical parameters and energies have been obtained from Density functional theory (DFT) B3LYP (6-31G (d, p)) basis set calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. 1H and 13C NMR chemical shifts of the molecule were calculated using Gauge-independent atomic orbital method (GIAO). The electronic properties such as excitation energies, wavelength, HOMO, LUMO energies performed by Time dependent density functional theory (TD-DFT) results complements with the experimental findings. NBO analysis has been performed for analyzing charge delocalization throughout the molecule. The calculation results were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. To provide information about the interactions between human cytochrome protein and the novel compound theoretically, docking studies were carried out using Schrödinger software.

Experimental (FT-IR, NMR and UV) and theoretical (M06-2X and DFT) investigation, and frequency estimation analyses on (E)-3-(4-bromo-5-methylthiophen-2-yl)acrylonitrile.

PubMed

Sert, Yusuf; Balakit, Asim A; Öztürk, Nuri; Ucun, Fatih; El-Hiti, Gamal A

2014-10-15

The spectroscopic properties of (E)-3-(4-bromo-5-methylthiophen-2-yl)acrylonitrile have been investigated by FT-IR, UV, (1)H and (13)C NMR techniques. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and DFT/M06-2X (the highly parameterized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been carried out by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies were in good agreement with the corresponding experimental data, and with the results in the literature. (1)H and (13)C NMR chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strength wavelengths were performed by B3LYP methods. In addition, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and the other related molecular energy values have been calculated and depicted. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, single crystal X-ray, spectroscopic (FT-IR, UV-vis, fluorescence, 1H &13C NMR), computational (DFT/B3LYP) studies of some imidazole based picrates

NASA Astrophysics Data System (ADS)

Arockia doss, M.; Rajarajan, G.; Thanikachalam, V.; Selvanayagam, S.; Sridhar, B.

2018-04-01

2,4,5-triphenyl-1H-imidazol-3-ium picrate (1), 2-(4-fluorophenyl)-4,5-diphenyl-1H-imidazol-3-ium picrate (2), 2-(4-methylphenyl)-4,5-diphenyl-1H-imidazol-3-ium picrate (3) were synthesised. These compounds 1-3 were characterized by elemental, FT-IR, 1H NMR and 13C NMR analyses. The structure of compound 3 was further confirmed by single crystal X-ray diffraction. The studies reveal that the molecule is associated with weak Nsbnd H⋯O and Csbnd H⋯N and van der Waals interactions which are responsible for the formation and strengthening of supramolecular assembly. The nature of the interactions and their importance are explored using the Hirshfeld surface method. The physicochemical properties of the compounds 1-3 were evaluated by UV-vis spectroscopy, fluorescence spectroscopy, and thermogravimetric analysis. According to thermal data the salts possess excellent thermal stabilities with decomposition temperatures ranging from 220 to 280 °C. Second-harmonic generation (SHG) results exposed that the picrates 1-3 were about 1.13-1.50 times greater than potassium dihydrogen phosphate (KDP). Here we also used Density functional theory (DFT) calculations in order to investigate the opto-electronic properties. The obtained theoretical results validate with available experimental data.

Synthesis, characterization, crystal structure and DNA-binding studies of transition metal hydrazone complexes

NASA Astrophysics Data System (ADS)

Kanchanadevi, S.; Parveen, S.; Mahalingam, V.

2018-04-01

Three new complexes containing salicylaldazine (HL) ligand were synthesised by reacting suitable precursor complex [MCl2(PPh3)2] with the ligand (where M = Cu(II) or Ni(II) or Co(II)). The new complexes were characterised by various spectral studies such as IR, UV-Vis,1H NMR,EPR,fluorescence and elemental analyses. The binding modes of the complexes with HS-DNA have been studied by UV-Vis absorption titration. Binding of the complexes with bovine serum albumin (BSA) protein has been investigated using UV-visible, fluorescence and synchronous fluorescence spectroscopic methods. Redox behaviour of the complexes has been investigated by cyclic voltammetry.

Spectroscopic (FT-IR, FT-Raman, FT-NMR and UV-Vis) investigation on benzil dioxime using quantum computational methods

NASA Astrophysics Data System (ADS)

Bakkiyaraj, D.; Periandy, S.; Xavier, S.

2016-03-01

The spectral analysis of benzil dioxime is carried out using the FTIR, FT Raman, FT NMR and UV-Vis spectra of the compound with the help of quantum computations by density functional theories. The FT-IR (4000 - 400 cm-1) and FT-Raman (4000-100 cm-1) spectra are recorded in solid phase, the 1H and 13C NMR spectra in DMSO phase and the UV spectrum (200-400 nm) in ethanol phase. The different conformers of the compound and their minimum energies are studied by potential energy surface scan, using semi-empirical method PM6. The computed wavenumbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the fundamental modes have been assigned based on the potential energy distribution (PED) values and the structure the molecule is analyzed interms of parameters like bond length, bond angle and dihedral angles predicted byB3LYP and CAM-B3LYP methods with cc-pVDZ basis sets. The values of dipole moment (μ), polarizability (α) and hyperpolarizability (β) of the molecule are reported, using which the non -linear optical property of the molecule is discussed. The HOMO-LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for 1H and 13C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts and the same is discussed in comparison with atomic charges, predicted by Mullikan and APT charge analysis. NBO analysis is carried out to picture the probable electronic transitions in the molecule.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreev, P. V., E-mail: andreev@phys.unn.ru; Somov, N. V.; Kalistratova, O. S.

The newly synthesized triphenylbismuth bis(3-phenylprop-2-enoate) was studied by X-ray diffraction and by IR, UV, and NMR spectroscopy. The crystals are monoclinic, sp. gr. C2/c, Z = 4, a = 13.2820(4) Å, b = 21.3750(2) Å, c = 12.2407(2) Å, β = 119.936(1)°. The coordination polyhedron of the bismuth atom can be described as a distorted pentagonal bipyramid.

Two aurone glycosides from heartwood of Pterocarpus santalinus.

PubMed

Kesari, Achyut Narayan; Gupta, Rajesh Kumar; Watal, Geeta

2004-12-01

Two new aurone glycosides, 6 hydroxy 5 methyl 3',4',5' trimethoxy aurone 4-O-alpha-L-rhamnopyranoside and 6,4' dihydroxy aurone 4-O-rutinoside have been isolated from the ethanolic extract of the wood of Pterocarpus santalinus. Their structures were determined on the basis of chemical and spectroscopic analysis (UV, IR, EIMS, (1)H and (13)C NMR).

Dithia[3.3]paracyclophane-based monometal ruthenium acetylide complexes: synthesis, characterization and substituent effects.

PubMed

Zhu, Xingxun; Ou, Yaping; Zhang, Jing; Xia, Jian-Long; Yin, Jun; Yu, Guang-Ao; Liu, Sheng Hua

2013-05-21

A series of dithia[3.3]metaparacyclophane-based monometal ruthenium acetylide complexes have been synthesized. All of the complexes have been fully characterised by NMR spectrometry, X-ray crystallography and elemental analyses. At the same time, their basic optical properties, such as UV/Vis absorption spectra, and electrochemical properties have been determined. (1)H NMR and X-ray crystal structure studies reveal that there are intramolecular C-H···π interactions in these ruthenium complexes, in both solution and solid states. Electrochemical studies reveal that the substituted groups on the dithia[3.3]paracyclophane ring can clearly affect the oxidation activities of the ruthenium center by way of the intramolecular C-H···π interaction. In addition, electron-donating groups facilitate the oxidation of the ruthenium center compared with electron-deficient groups. UV/Vis absorption and IR spectra of some complexes in neutral and oxidized states also have been studied. IR spectra studies indicated that the substituents in the cyclophane have some effects on the ν(C≡C) bands of these complexes in the neutral state and little effect on ν(C≡C) of these complexes in the oxidized state.

Molecular structure and spectroscopic characterization of Carbamazepine with experimental techniques and DFT quantum chemical calculations.

PubMed

Suhasini, M; Sailatha, E; Gunasekaran, S; Ramkumaar, G R

2015-04-15

A systematic vibrational spectroscopic assignment and analysis of Carbamazepine has been carried out by using FT-IR, FT-Raman and UV spectral data. The vibrational analysis were aided by electronic structure calculations - ab initio (RHF) and hybrid density functional methods (B3LYP) performed with standard basis set 6-31G(d,p). Molecular equilibrium geometries, electronic energies, natural bond order analysis, harmonic vibrational frequencies and IR intensities have been computed. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED) by VEDA program. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λmax were determined by HF/6-311++G(d,p) Time-Dependent method. The thermodynamic functions of the title molecule were also performed using the RHF and DFT methods. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the (13)C and (1)H NMR chemical shifts of Carbamazepine. Copyright © 2015 Elsevier B.V. All rights reserved.

Puupehenol, a potent antioxidant antimicrobial meroterpenoid from a Hawaiian deep-water Dactylospongia sp. sponge.

PubMed

Hagiwara, Kehau; Garcia Hernandez, Jaaziel E; Harper, Mary Kay; Carroll, Anthony; Motti, Cherie A; Awaya, Jonathan; Nguyen, Hoang-Yen; Wright, Anthony D

2015-02-27

From the organic extract of a deep-water Hawaiian sponge Dactylospongia sp., a new potent antioxidant and antimicrobial meroterpenoid, puupehenol (1), was isolated. The structure of 1 was determined using spectroscopic techniques ((1)H and (13)C NMR, MS, IR, UV, [α]D). The known compound puupehenone (2) was also isolated and suggested as a probable artifact of the isolation procedures. Complete unambiguous (1)H and (13)C NMR data are provided for compounds 1 and 2. Bioassays performed with 1 and 2 showed them both to be very effective antioxidants and to have antimicrobial properties.

[Studies on the flavonoids from Dendranthema lavandulifolium].

PubMed

Shen, Y X; Quan, L H; Guan, L; Chen, J M

1997-06-01

From the whole plant of Dendranthema lavandulifolium, two flavonoides (I, II) and two flavone glycosides (III, IV) were isolated. They were identified as luteolin (I), apigenin (II), 5-hydroxy-4'-methoxy-flavone-7-O-alpha-L-rhamnopyranosyl(1-->6)-beta- D-glucopyranosyl (acaciin III) and 5-hydroxy-4'-methoxy-flavone-7-O-alpha-L-rhamnopyranosyl (1-->6) [2-O-acetyl-beta-D-glucopyranosyl(1-->2)]-beta-D-glucopyranoside (IV) by means of IR, UV, 1H-NMR, 13C-NMR, EI-MS, HRFAB, etc. Among these four compounds, I, II were isolated for the first time from this plant, IV is a new compound.

Direct synthesis of graphitic mesoporous carbon from green phenolic resins exposed to subsequent UV and IR laser irradiations

PubMed Central

Sopronyi, Mihai; Sima, Felix; Vaulot, Cyril; Delmotte, Luc; Bahouka, Armel; Matei Ghimbeu, Camelia

2016-01-01

The design of mesoporous carbon materials with controlled textural and structural features by rapid, cost-effective and eco-friendly means is highly demanded for many fields of applications. We report herein on the fast and tailored synthesis of mesoporous carbon by UV and IR laser assisted irradiations of a solution consisting of green phenolic resins and surfactant agent. By tailoring the UV laser parameters such as energy, pulse repetition rate or exposure time carbon materials with different pore size, architecture and wall thickness were obtained. By increasing irradiation dose, the mesopore size diminishes in the favor of wall thickness while the morphology shifts from worm-like to an ordered hexagonal one. This was related to the intensification of phenolic resin cross-linking which induces the reduction of H-bonding with the template as highlighted by 13C and 1H NMR. In addition, mesoporous carbon with graphitic structure was obtained by IR laser irradiation at room temperature and in very short time periods compared to the classical long thermal treatment at very high temperatures. Therefore, the carbon texture and structure can be tuned only by playing with laser parameters, without extra chemicals, as usually required. PMID:28000781

New mixed ligand palladium(II) complexes based on the antiepileptic drug sodium valproate and bioactive nitrogen-donor ligands: Synthesis, structural characterization, binding interactions with DNA and BSA, in vitro cytotoxicity studies and DFT calculations

NASA Astrophysics Data System (ADS)

Tabrizi, Leila; Chiniforoshan, Hossein; Tavakol, Hossein

2015-04-01

The complexes [Pd(valp)2(imidazole)2] (1), [Pd(valp)2(pyrazine)2] (2) (valp is sodium valproate) have been synthesized and characterized using IR, 1H NMR, 13C{1H} NMR and UV-Vis spectrometry. The interaction of complexes with CT-DNA has been investigated using spectroscopic tools and viscosity measurement. In each case, the association constant (Kb) was deduced from the absorption spectral study and the number of binding sites (n) and the binding constant (K) were calculated from relevant fluorescence quenching data. As a result, a non-covalent interaction between the metal complex and DNA was suggested, which could be assigned to an intercalative binding. In addition, the interaction of 1 and 2 was ventured with bovine serum albumin (BSA) with the help of absorption and fluorescence spectroscopy measurements. Through these techniques, the apparent association constant (Kapp) and the binding constant (K) could be calculated for each complex. Evaluation of cytotoxic activity of the complexes against four different cancer cell lines proved that the complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate. Moreover, density functional theory (DFT) calculations were employed to provide more evidence about the observed data. The majority of trans isomers were supported not only by energies, but also by the similarity of its calculated IR frequencies, UV adsorptions and NMR chemical shifts to the experimental values.

Solution Structures of Highly Active Molecular Ir Water-Oxidation Catalysts from Density Functional Theory Combined with High-Energy X-ray Scattering and EXAFS Spectroscopy.

PubMed

Yang, Ke R; Matula, Adam J; Kwon, Gihan; Hong, Jiyun; Sheehan, Stafford W; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H; Tiede, David M; Chen, Lin X; Batista, Victor S

2016-05-04

The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that the catalysts are Ir dimers with mono-μ-O cores and terminal anionic ligands, generated in situ through partial oxidation of a common catalyst precursor. The proposed structures are supported by (1)H and (17)O NMR, EPR, resonance Raman and UV-vis spectra, electrophoresis, etc. Our findings are particularly valuable to understand the mechanism of water oxidation by highly reactive Ir catalysts. Importantly, our DFT-EXAFS-HEXS methodology provides a new in situ technique for characterization of active species in catalytic systems.

Inclusion complexes of β-cyclodextrin-dinitrocompounds as UV absorber for ballpoint pen ink.

PubMed

Srinivasan, Krishnan; Radhakrishnan, S; Stalin, Thambusamy

2014-08-14

2,4-Dinitrophenol (2,4-DNP), 2,4-dinitroaniline (2,4-DNA), 2,6-dinitroaniline (2,6-DNA) and 2,6-dinitrobenzoic acid (2,6-DNB) has appeared for the UV absorption bands in different wavelength region below 400 nm, a combination of these dinitro aromatic compounds gave the broad absorption spectra within the UV region. The absorption intensities have been increased by preparation of the inclusion complex of dinitro compounds with β-cyclodextrin (β-CD). Prepared inclusion complexes are used to improve the UV protection properties of the ball point pen ink against photo degradation. The formation of solid inclusion complexes was characterized by FT-IR, and (1)H NMR spectroscopy. The UV protecting properties of these inclusion complexes were calculated their sun protection factor (SPF) is also discussed. The stability of the ballpoint pen ink has been confirmed by UV-Visible spectroscopic method. Copyright © 2014 Elsevier B.V. All rights reserved.

Generation and characterization of highly strained dibenzotetrakisdehydro[12]- and dibenzopentakisdehydro[14]annulenes.

PubMed

Hisaki, Ichiro; Eda, Takeshi; Sonoda, Motohiro; Niino, Hiroyuki; Sato, Tadatake; Wakabayashi, Tomonari; Tobe, Yoshito

2005-03-04

To generate dibenzotetrakisdehydro[12]- and dibenzopentakisdehydro[14]annulenes ([12]- and [14]DBAs) having a highly deformed triyne moiety, [4.3.2]propellatriene-anneleted dehydro[12]- and dehydro[14]annulenes were prepared as their precursors. UV irradiation of the precursors resulted in the photochemical [2 + 2] cycloreversion to generate the strained [12]- and [14]DBAs, respectively. The [12]DBA was not detected by 1H NMR spectroscopy, but it was intercepted as Diels-Alder adducts in solution, suggesting its intermediacy. Its spectroscopic characterization was successfully carried out by UV-vis spectroscopy in a 2-methyltetrahydrofuran (MTHF) glass matrix at 77 K and by FT-IR spectroscopy in an argon matrix at 20 K. On the other hand, the [14]DBA was stable enough for observation by 1H and 13C NMR spectra in solution, though it was not isolated because of the low efficiency of the cycloreversion. The [14]DBA was also characterized by interception as Diels-Alder adducts in solution and by UV-vis spectroscopy in a MTHF glass matrix at 77 K. The kinetic stabilities of the DBAs are compared with the related dehydrobenzoannulenes with respect to the topology of the pi-systems. In addition, the tropicity of the [14]DBA is discussed based on its experimental and theoretical 1H NMR chemical shifts.

Three new metabolites from Botrytis cinerea.

PubMed

Wang, Tian-Shan; Zhou, Jin-Yan; Tan, Hong

2008-01-01

Three new metabolites, gamma-abscisolactone (1), botrytisic acids A (3) and B (4) were isolated from the fermentation broth of Botrytis cinerea TB-3-H8. Their structures were elucidated on the basis of MS, IR, UV, and NMR spectroscopic data. Compound 2 was isolated from natural resource for the first time. The structure of 1 was further confirmed by single-crystal X-ray diffraction (CCDC-265897).

Bonding Properties of a Novel Inorganometallic Complex, Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) (iPr-DAB = N,N'-Diisopropyl-1,4-diaza-1,3-butadiene), and its Stable Radical-Anion, Studied by UV-Vis, IR, and EPR Spectroscopy, (Spectro-) Electrochemistry, and Density Functional Calculations.

PubMed

Aarnts, Maxim P.; Wilms, Maikel P.; Peelen, Karin; Fraanje, Jan; Goubitz, Kees; Hartl, Frantisek; Stufkens, Derk J.; Baerends, Evert Jan; Vlcek, Antonín

1996-09-11

Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) was synthesized and characterized by UV-vis, IR, (1)H NMR, (13)C NMR, (119)Sn NMR, and mass (FAB(+)) spectroscopies and by single-crystal X-ray diffraction, which proved the presence of a nearly linear Sn-Ru-Sn unit. Crystals of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB).3.5C(6)H(6) form in the triclinic space group P&onemacr; in a unit cell of dimensions a = 11.662(6) Å, b = 13.902(3) Å, c = 19.643(2) Å, alpha = 71.24(2) degrees, beta = 86.91(4) degrees, gamma = 77.89(3) degrees, and V = 2946(3) Å(3). One-electron reduction of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) produces the stable radical-anion [Ru(SnPh(3))(2)(CO)(2)(iPr-DAB)](*-) that was characterized by IR, and UV-vis spectroelectrochemistry. Its EPR spectrum shows a signal at g = 1.9960 with well resolved Sn, Ru, and iPr-DAB (H, N) hyperfine couplings. DFT-MO calculations on the model compound Ru(SnH(3))(2)(CO)(2)(H-DAB) reveal that the HOMO is mainly of sigma(Sn-Ru-Sn) character mixed strongly with the lowest pi orbital of the H-DAB ligand. The LUMO (SOMO in the reduced complex) should be viewed as predominantly pi(H-DAB) with an admixture of the sigma(Sn-Ru-Sn) orbital. Accordingly, the lowest-energy absorption band of the neutral species will mainly belong to the sigma(Sn-Ru-Sn)-->pi(iPr-DAB) charge transfer transition. The intrinsic strength of the Ru-Sn bond and the delocalized character of the three-center four-electron Sn-Ru-Sn sigma-bond account for the inherent stability of the radical anion.

Spectroscopic analysis of cinnamic acid using quantum chemical calculations

NASA Astrophysics Data System (ADS)

Vinod, K. S.; Periandy, S.; Govindarajan, M.

2015-02-01

In this present study, FT-IR, FT-Raman, 13C NMR and 1H NMR spectra for cinnamic acid have been recorded for the vibrational and spectroscopic analysis. The observed fundamental frequencies (IR and Raman) were assigned according to their distinctiveness region. The computed frequencies and optimized parameters have been calculated by using HF and DFT (B3LYP) methods and the corresponding results are tabulated. On the basis of the comparison between computed and experimental results assignments of the fundamental vibrational modes are examined. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by HF and DFT methods. The alternation of the vibration pattern of the pedestal molecule related to the substitutions was analyzed. The 13C and 1H NMR spectra have been recorded and the chemical shifts have been calculated using the gauge independent atomic orbital (GIAO) method. The Mulliken charges, UV spectral analysis and HOMO-LUMO analysis of have been calculated and reported. The molecular electrostatic potential (MEP) was constructed.

Synthesis, spectroscopy, X-ray crystallography, DFT calculations, DNA binding and molecular docking of a propargyl arms containing Schiff base.

PubMed

Balakrishnan, C; Subha, L; Neelakantan, M A; Mariappan, S S

2015-11-05

A propargyl arms containing Schiff base (L) was synthesized by the condensation of 1-[2-hydroxy-4-(prop-2-yn-1-yloxy)phenyl]ethanone with trans-1,2-diaminocyclohexane. The structure of L was characterized by IR, (1)H NMR, (13)C NMR and UV-Vis spectroscopy and by single crystal X-ray diffraction analysis. The UV-Visible spectral behavior of L in different solvents exhibits positive solvatochromism. Density functional calculation of the L in gas phase was performed by using DFT (B3LYP) method with 6-31G basis set. The computed vibrational frequencies and NMR signals of L were compared with the experimental data. Tautomeric stability study inferred that the enolimine is more stable than the ketoamine form. The charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Electronic absorption and emission spectral studies were used to study the binding of L with CT-DNA. The molecular docking was done to identify the interaction of L with A-DNA and B-DNA. Copyright © 2015 Elsevier B.V. All rights reserved.

QM/MM methodology, docking and spectroscopic (FT-IR/FT-Raman, NMR, UV) and Fukui function analysis on adrenergic agonist

NASA Astrophysics Data System (ADS)

Uma Maheswari, J.; Muthu, S.; Sundius, Tom

2015-02-01

The Fourier transform infrared, FT-Raman, UV and NMR spectra of Ternelin have been recorded and analyzed. Harmonic vibrational frequencies have been investigated with the help of HF with 6-31G (d,p) and B3LYP with 6-31G (d,p) and LANL2DZ basis sets. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. The polarizability (α) and the first hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. Stability of the molecule arising from hyper conjugative interactions, and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in Ternelin. Finally the calculated results were compared to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. Molecular docking studies have been carried out in the active site of Ternelin and reactivity with ONIOM was also investigated.

Design of UV-absorbing PVDF membrane via surface-initiated AGET ATRP

NASA Astrophysics Data System (ADS)

Dong, Li; Liu, Xiangdong; Xiong, Zhengrong; Sheng, Dekun; Zhou, Yan; Lin, Changhong; Yang, Yuming

2018-03-01

Herein, PVDF membranes with excellent UV-absorbing property were first synthesized through grafting the polymerizable low-molecular-weight organic UV-absorber 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) onto α-bromoester-functionalized PVDF membranes via the surface-initiated activator generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). The surface initiators were immobilized by the reaction between 2-bromoisobutyryl bromide (BIBB) and the hydroxylated PVDF membranes. PVDF-g-PBPMA membranes with different grafting densities were obtained by tuning the polymerization time and the modified membranes were characterized by 1H-NMR, FT-IR, XPS, SEM, UV-vis Spectrophotometer, TGA and DSC. The experimental results indicated that PBPMA chains were successfully introduced onto PVDF membranes. Most importantly, the PVDF-g-PBPMA membranes exhibited outstanding UV-shielding property. UV-vis transmittance spectra showed that most UV light below 360 nm could be absorbed by PVDF-g-PBPMA membranes and the whole UV light region (200-400 nm) can be blocked with the reaction time increased.

Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa.

PubMed

Nidiry, Eugene Sebastian J; Ganeshan, Girija; Lokesha, Ankanahalli N

2011-12-01

Bioassay monitored HPLC assisted isolation and purification of the chief antifungal fraction of the leaves of Ipomoea carnea subsp. fistulosa (Convulvulaceae) were achieved using Colletotrichum gloeosporioides and Cladosporium cucumerinum as test organisms. The activity of the purified fraction was further confirmed by the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri. The active fraction was identified as a mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate. The two isomers were detected on an HPLC column with substantially different retention times, but once eluted from the column, one form was partly converted to the other in daylight. Conclusive evidence for the structures and their isomerization were obtained from the HPLC behavior, IR, UV, HRESIMS, CIMS and and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques.

Synthesis and biological activity of hydrazide hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles

USDA-ARS?s Scientific Manuscript database

Various new 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles (11-20) were prepared by the reaction of aryl substituted hydrazones of 4-fluorobenzoic acid hydrazide (1-10) with acetic anhydride. The structures of the newly synthesized compounds 11-20, were confirmed by UV, IR and 1H NMR spec...

A new nortriterpenoid and an ergostane-type steroid from the fruiting bodies of the fungus Ganoderma resinaceum.

PubMed

Chen, Xian-Qiang; Chen, Ling-Xiao; Li, Shao-Ping; Zhao, Jing

2017-12-01

One new expoxy nortriterpenoid (1) and one new ergostane-type steroid (2), together with seven known steroids (3-9), were obtained from the fruiting bodies of the fungus Ganoderma resinaceum. The new compounds were elucidated on the basis of extensive spectroscopic data (MS, NMR, IR, and UV) and the known compounds were identified by comparing spectroscopic data with those reported in literature.

[Studies on the identification of psychotropic substances. VIII. Preparation and various analytical data of reference standard of some stimulants, amfepramone, cathinone, N-ethylamphetamine, fenethylline, fenproporex and mefenorex].

PubMed

Shimamine, M; Takahashi, K; Nakahara, Y

1992-01-01

The Reference Standards for amfepramone, cathinone, N-ethylamphetamine, fenethylline, fenproporex and mefenorex were prepared. Their purities determined by HPLC were more than 99.5%. For the identification and determination of these six drugs, their analytical data were measured and discussed by TLC, UV, IR, HPLC, GC/MS and NMR.

Synthesis, structural characterization, antimicrobial activities and theoretical investigations of some 4-(4-aminophenylsulfonyl) phenylimino) methyl)-4-(aryldiazenyl) phenol

NASA Astrophysics Data System (ADS)

Ghasemian, Motaleb; Kakanejadifard, Ali; Karami, Tahereh

2016-11-01

The azo-azomethine dyes with a different substitution have been designed from the reaction of 4,4‧-diaminodiphenyl sulfone with 2-hydroxy-5-(aryldiazenyl)benzaldehyde. The compounds have been characterized by elemental analysis, Mass, IR, UV-Vis, TGA-DTA and NMR spectroscopy. The solvatochromism behaviors, effects of substitution and pH on the electronic absorption spectra of dyes were evaluated. The in vitro antimicrobial activities were also screened for their potential for antibiotic activities by broth micro dilution method. Also, the optimum molecular geometries, molecular electrostatic potential (MEP), nucleus-independent chemical shift (NICS) and frontier molecular orbitals (FMO), vibrational spectra (IR) and electronic absorption (UV-Vis) spectra of the title compounds have been investigated with the help of DFT and TDDFT methods with 6-311 ++G(d,p) basis sets and PCM calculations. The results of the calculations show excellent agreement with the experimental value.

Theoretical and experimental studies of 3β-acetoxy-5α-cholestan-6-one oxime

NASA Astrophysics Data System (ADS)

Khan, Azhar U.; Avecillia, Fernando; Malik, Nazia; Khan, Md. Shahzad; Khan, Mohd Shahid; Mushtaque, Md.

2016-10-01

Steroidal oxime (3β-acetoxy-5α-cholestan- 6-one oxime) has been synthesized using microwave-induced reaction in 3.5 min using saturated steroidal ketone and aqueous hydroxylamine hydrochloride in ethanol. The structure of the compound was elucidated by UV, IR, 1H NMR and X-ray single crystal structure. The computational quantum chemical studies like, IR, UV analysis were performed by density functional theory (DFT) at Becke-3-Lee-Yang-Parr(B3LYP) exchange-correlation functional in combination with 6-31++G(d,p) basis sets. The harmonic vibrational frequencies, the optimized geometric parameters have been interpreted and compared with experimental values. Theoretical wavelength at 214.88 cm-1 correspond to the experimental value 214.0 cm-1. The nature of this transition is n → π*. The theoretical results are in good agreement with experiment results.

Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

NASA Astrophysics Data System (ADS)

Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

2012-11-01

Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

Synthesis and spectroscopic properties of novel asymmetric Schiff bases.

PubMed

Güngör, Ozlem; Gürkan, Perihan

2010-09-15

Three novel diimine Schiff bases including two asymmetric imines (2-OH)R-CHN-C(6)H(4)-CHN-R'(2-OH) type [where R=R'=phenyl for H(2)L(1); R=naphthyl, R'=phenyl for H(2)L(2) and R=R'=naphthyl for H(2)L(3)] have been synthesized with a new two step method. For this purpose, the starting Schiff bases 4-nitrobenzylidene-2-hydroxyaniline (SB(1)-NO(2)) and 4-nitrobenzylidene-2-hydroxy-3-naphthylamine (SB(2)-NO(2)) have been synthesized, previously. Nitro groups of them have been reduced into their amino derivatives (SB(1)-NH(2) and SB(2)-NH(2)) with sodium dithionite as selective reductant and the other imino groups have been formed by adding salicylaldehyde or 2-hydroxy-1-naphthaldehyde to the same solutions. The structures of the diimine Schiff bases were confirmed by elemental analyses, ESI-MS, FT-IR, (1)H NMR and (13)C NMR spectroscopy. The phenol-imine and keto-amine tautomerism of the Schiff bases were investigated by FT-IR, (1)H NMR, (13)C NMR techniques and UV-vis spectra in different solvents (DMSO, methanol, chloroform, toluene and cyclohexane). The effects of acidic and basic media on the tautomeric equilibria were discussed. Copyright 2010 Elsevier B.V. All rights reserved.

Molecular structure, spectroscopic (FT-IR, FT Raman, UV, NMR and THz) investigation and hyperpolarizability studies of 3-(2-Chloro-6-fluorophenyl)-1-(2-thienyl) prop-2-en-1-one

NASA Astrophysics Data System (ADS)

Kumar, Rajesh; Kumar, Amit; Deval, Vipin; Gupta, Archana; Tandon, Poonam; Patil, P. S.; Deshmukh, Prathmesh; Chaturvedi, Deepika; Watve, J. G.

2017-02-01

In the present work, a combined experimental and theoretical study on ground state molecular structure, spectroscopic and nonlinear optical properties of the chalcone derivative 3-(2-Chloro-6-fluorophenyl)-1-(2-thienyl) prop-2-en-1-one (2C6F2SC) is reported. Initial geometry generated from single crystal X-ray diffraction parameters was minimized at DFT level employing B3LYP/6-311++G (d,p) without any constraint to the potential energy surface. The molecule has been characterized using various experimental techniques FT-IR, FT-Raman, UV-Vis, 1H NMR, TD-THz and the spectroscopic data have been analyzed theoretically by Density Functional Theory (DFT) method. Harmonic vibrational frequencies were calculated theoretically using the optimized ground state geometry and the spectra were interpreted by means of potential energy distribution. Time Dependent Density Functional Theory (TD-DFT) has been used to calculate energies, absorption wavelengths, oscillator strengths of electronic singlet-singlet transitions. The calculated energy and oscillator strength complement with the experimental findings. The HOMO-LUMO energy gap explains the charge interaction taking place within the molecule. Good correlations between the experimental 1H NMR chemical shifts and calculated GIAO shielding tensors were found. Stability of the molecule, hyperconjugative interactions and charge delocalization has been analyzed by natural bond orbital (NBO) analysis. The first order hyperpolarizability (β) of this molecular system and related properties (μ, <α> and Δα) have been calculated using the finite-field approach.

Synthesis, spectroscopic investigations (FT-IR, NMR, UV-Vis, and TD-DFT), and molecular docking of (E)-1-(benzo[d][1, 3]dioxol-6-yl)-3-(6-methoxynaphthalen-2-yl)prop-2-en-1-one

NASA Astrophysics Data System (ADS)

Therasa Alphonsa, A.; Loganathan, C.; Athavan Alias Anand, S.; Kabilan, S.

2017-02-01

The compound (E)-1-(benzo [d] [1, 3] dioxol-6-yl)-3-(6-methoxy naphthalen-2-yl) prop-2-en-1-one (AKN) was synthesized and characterized by FT-IR, NMR, and UV-Vis spectrometer. The optimized molecular geometry, bond lengths, bond angles, atomic charges, harmonic vibrational wave numbers and intensities of vibrational bonds of the title compound have been investigated by Time dependent- Density Functional Theory (TD-DFT) using a standard B3LYP method with 6-31 G (d, p) basis set available in the Gaussian 09W package. 1H and 13C NMR chemical shifts of the molecule were calculated using Gauge-independent atomic orbital method (GIAO). Experimental excitation energies of the molecules were matched with the theoretically calculated energies. The atomic charge distributions of the various atoms present in the AKN were obtained by Mulliken charge population analysis. The Molecular Electrostatic Potential (MEP) analysis reveals the sites for electrophilic attack and nucleophilic reactions in the molecule. The difference between the observed and scaled frequencies was small. The HOMO to LUMO transition implies an electron density transfer. The intramolecular contacts have been interpreted using Natural Bond Orbital (NBO) analysis. The calculation results were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. To provide information about the interactions between human cytochrome protein and the novel compound theoretically, docking studies were carried out using Schrödinger software.

Spectroscopic and DFT studies of bis-3-hydroxypyridinium and bis-3-hydroxymethylpyridinium dibromides with tetramethylene linker

NASA Astrophysics Data System (ADS)

Komasa, Anna

2018-01-01

Experimental and theoretical IR, Raman, UV-Vis, 1H and 13C NMR spectra of 1,4-di(3-hydroxypyridinium)butane dibromide and 1,4-di(3-hydroxymethylpyridinium)butane dibromide were obtained and analyzed. Optimized geometrical structures of the studied compounds were calculated by B3LYP method using 6-311++G(d,p) basis set and employed to determine the theoretical wavenumbers and intensities of IR and Raman spectra. The frequency assignments were supported by the potential energy distribution (PED) analysis. The significant role of the intermolecular interactions and the hydrogen bond was revealed on the basis of IR spectra. The calculated GIAO/B3LYP/6-311++G(d,p) isotropic magnetic shielding constants were used to predict the 1H and 13C chemical shifts for the optimized structures. Accuracy of the prediction of 1H and 13C chemical shifts was significantly improved by a simulation of the solvent in calculations. On the basis of UV-Vis spectra the acid-base equilibrium in the water solution of 1,4-di(3-hydroxypyridinium)butane dibromide was found.

An investigation onto the molecular structure of 5-chloro-3-(2-(4-ethylpiperazine-1-il)-2-oxoethyl)benzo[d]thiazole-2(3H)-on drug molecule before and after atmospheric pressure plasma treatment

NASA Astrophysics Data System (ADS)

Tanışlı, Murat; Taşal, Erol; Şahin, Neslihan; Dikmen, Gökhan

2018-05-01

The spectra of molecular structure for the 5-chloro-3-(2-(4-ethylpiperazine-1-il)-2-oxoethyl)benzo[d]thiazole-2(3H)-on drug molecule (abbreviated as 5KEB) before and after the atmospheric pressure plasma treatments (APPTs) of neon (Ne) and argon (Ar) were investigated. The Fourier transform infrared (FT-IR), ultraviolet visible (UV-Vis) spectra and NMR measurements of the 5KEB drug molecule dissolved in toluene and ethanol solvents were recorded and examined for liquid phases. Then FT-IR, UV-Vis spectra and NMR measurements were analysed. It is seen that some bonds of 5KEB molecule were decomposed. There were also unobserved vibrational modes. After the Ne plasma at the atmospheric pressure applied to 5KEB drug molecule dissolved in toluene, the bonds as 9Ssbnd 8C; 9Ssbnd 8C = 10 O, 8Csbnd 7N, 7Nsbnd 8C = 10O were vanished, and then the new bonds of the 7N = 8C, 7N = 8C = 10 O, 9Ssbnd 5Csbnd 4Csbnd 7N = 8C = 10O were observed. New photoproducts may be defined as the stretching peaks, stretching vibrational modes for 5KEB drug molecule in liquid phase prepared with ethanol and toluene solvents after APPT. Also, after Ar plasma at atmospheric pressure applied here, the 9Ssbnd 8C bond of the 5KEB drug molecule dissolved in toluene was broken. The isomerization process in UV-Vis was defined by π-π* and n-π* electronic transitions. According to NMR results, protons of pyridine ring, protons of CH2 group bonded to carbonyl group and protons of CH3 group more affected than other protons from Ar and Ne APPTs and these protons were eliminated by Ar and Ne APPTs.

A new phenol glycoside from Physalis angulata.

PubMed

Sun, Cheng-Peng; Nie, Xiu-Fang; Kang, Ning; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

2017-05-01

A new phenol glycoside, physanguloside A (1), was isolated from Physalis angulata together with four known compounds. We report herein, for the first time, the presence of compounds 2-5 in the genus Physalis. The structures of all the compounds were established by NMR, IR, UV and HRESIMS spectroscopic analyses, and comparison with the literature data. All isolated compounds were assayed for inhibitory activity on nitric oxide production by LPS-induced in RAW 264.7 macrophages.

Two new compounds from Helichrysum arenarium (L.).

PubMed

Zhang, Yu-Wei; Sun, Wu-Xing; Li, Xian; Zhao, Chun-Chao; Meng, Da-Li; Li, Ning

2009-01-01

Two new compounds were isolated from the whole plant of Helichrysum arenarium (L.) Moench. By means of spectroscopic data (IR, UV, 1D and 2D NMR, HR-MS, ESI-MS, and NOESY) and chemical evidence, the structures were established as 6,7-dimethoxy-4-hydroxy-1-naphthoic acid (1) and (Z)-5-hydroxy-7-methoxy-4-[3-methyl-4-(O-beta-D-xylopyranosyl)but-2-enyl]isobenzofuran-1(3H)-one (2).

Five New Alkaloids from the Roots of Sophora flavescens.

PubMed

Zhang, Sheng-Yuan; Li, Wen; Nie, Hua; Liao, Mei; Qiu, Bo; Yang, Ya-Li; Chen, Yan-Fen

2018-03-01

Five new quinolizidine alkaloids, including three sparteine-type alkaloids (1 - 3) and two cytisine-type alkaloids (4 and 5), along with four known ones, were isolated from the roots of Sophora flavescens. Their structures were determined by extensive spectroscopic techniques including IR, UV, NMR, and HR-ESI-MS. All the compounds were evaluated for their antibacterial activities against Staphylococcus aureus and Escherichia coli. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

NASA Astrophysics Data System (ADS)

Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

2014-01-01

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

Isolation, spectroscopic and density functional theory studies of 7-(4-methoxyphenyl)-9H-furo[2,3-f]chromen-9-one: a new flavonoid from the bark of Millettia ovalifolia.

PubMed

Taj Ur Rahman; Arfan, Mohammad; Mahmood, Tariq; Liaqat, Wajiha; Gilani, Mazhar Amjad; Uddin, Ghias; Ludwig, Ralf; Zaman, Khair; Choudhary, M Iqbal; Khattak, Khanzadi Fatima; Ayub, Khurshid

2015-07-05

The phytochemical examination of chloroform soluble fraction (FX2) of methanolic extract of bark of Millettia ovalifolia yielded a new flavonoid; 7-(4-methoxyphenyl)-9H-furo [2,3-f]chromen-9-one (1). Compound 1 is characterized by spectroscopic analytical techniques such as UV, IR, 1D, 2D NMR spectroscopy, and mass spectrometry. A theoretical model is also developed for obtaining geometric, electronic and spectroscopic properties of 1. The geometry optimization and harmonic vibration simulations have been carried out at B3LYP/6-31G(d,p). The vibrational spectrum of compound 1 shows nice correlation with the experimental IR spectrum, through a scaling factor of 0.9613. (1)H and (13)C NMR chemical shifts are simulated using Cramer's re-parameterized function WP04 at 6-31G(d,p) basis set, and correlate nicely with the experimental chemical shifts. Copyright © 2015 Elsevier B.V. All rights reserved.

Isolation, spectroscopic and density functional theory studies of 7-(4-methoxyphenyl)-9H-furo[2,3-f]chromen-9-one: A new flavonoid from the bark of Millettia ovalifolia

NASA Astrophysics Data System (ADS)

Rahman, Taj Ur; Arfan, Mohammad; Mahmood, Tariq; Liaqat, Wajiha; Gilani, Mazhar Amjad; Uddin, Ghias; Ludwig, Ralf; Zaman, Khair; Choudhary, M. Iqbal; Khattak, Khanzadi Fatima; Ayub, Khurshid

2015-07-01

The phytochemical examination of chloroform soluble fraction (FX2) of methanolic extract of bark of Millettia ovalifolia yielded a new flavonoid; 7-(4-methoxyphenyl)-9H-furo [2,3-f]chromen-9-one (1). Compound 1 is characterized by spectroscopic analytical techniques such as UV, IR, 1D, 2D NMR spectroscopy, and mass spectrometry. A theoretical model is also developed for obtaining geometric, electronic and spectroscopic properties of 1. The geometry optimization and harmonic vibration simulations have been carried out at B3LYP/6-31G(d,p). The vibrational spectrum of compound 1 shows nice correlation with the experimental IR spectrum, through a scaling factor of 0.9613. 1H and 13C NMR chemical shifts are simulated using Cramer's re-parameterized function WP04 at 6-31G(d,p) basis set, and correlate nicely with the experimental chemical shifts.

IR, 1H NMR, mass, XRD and TGA/DTA investigations on the ciprofloxacin/iodine charge-transfer complex.

PubMed

Refat, Moamen S; El-Hawary, W F; Moussa, Mohamed A A

2011-05-01

The charge-transfer complex (CTC) of ciprofloxacin drug (CIP) as a donor with iodine (I(2)) as a sigma acceptor has been studied spectrophotometrically in CHCl(3). At maximum absorption bands, the stoichiometry of CIP:iodine system was found to be 1:1 ratio according to molar ratio method. The essential spectroscopic data like formation constant (K(CT)), molar extinction coefficient (ɛ(CT)), standard free energy (ΔG°), oscillator strength (f), transition dipole moment (μ), resonance energy (R(N)) and ionization potential (I(D)) were estimated. The spectroscopic techniques such as IR, (1)H NMR, mass and UV-vis spectra and elemental analyses (CHN) as well as TG-DTG and DTA investigations were used to characterize the chelating behavior of CIP/iodine charge-transfer complex. The iodine CT interaction was associated with a presence of intermolecular hydrogen bond. The X-ray investigation was carried out to investigate the iodine doping in the synthetic CT complex. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of UV-B radiation on the isoflavone accumulation and physiological-biochemical changes of soybean during germination: Physiological-biochemical change of germinated soybean induced by UV-B.

PubMed

Ma, Meng; Wang, Pei; Yang, Runqiang; Gu, Zhenxin

2018-06-01

In this study, the effects of UV-B radiation on the isoflavones accumulation, physiological and nutritional quality, water status, and characteristics of proteins in germinated soybeans were investigated. The results showed that isoflavones content in soybeans increased with appropriate intensity and time of UV-B radiation and decreased with excessive treatment. Fresh weight, length, free amino acids, reducing sugar contents and bulk water (T 23 ) in germinated soybeans decreased with increasing radiation time, indicating that UV-B inhibited the growth and nutrients metabolism of soybean during germination. Cell damage was detected in germinated soybeans with excessive UV-B radiation, as shown by the black spots in cotyledons and the increased intercellular water determined by LF-NMR. Germination resulted in an increase in random coil structures, while UV-B radiation induced no obvious changes in FT-IR spectrum and protein conformation of soybeans. Both UV-B radiation and germination caused the increase in soluble proteins, especially in 1.0-75.0 kDa fraction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Spectroscopic (FT-IR, FT-Raman and UV-Visible) investigations, NMR chemical shielding anisotropy (CSA) parameters of 2,6-Diamino-4-chloropyrimidine for dye sensitized solar cells using density functional theory.

PubMed

Gladis Anitha, E; Joseph Vedhagiri, S; Parimala, K

2015-02-05

The molecular structure, geometry optimization, vibrational frequencies of organic dye sensitizer 2,6-Diamino-4-chloropyrimidine (DACP) were studied based on Hartree-Fock (HF) and density functional theory (DFT) using B3LYP methods with 6-311++G(d,p) basis set. Ultraviolet-Visible (UV-Vis) spectrum was investigated by time dependent DFT (TD-DFT). Features of the electronic absorption spectrum in the UV-Visible regions were assigned based on TD-DFT calculation. The absorption bands are assigned to transitions. The interfacial electron transfer between semiconductor TiO2 electrode and dye sensitizer DACP is due to an electron injection process from excited dye to the semiconductor's conduction band. The observed and the calculated frequencies are found to be in good agreement. The energies of the frontier molecular orbitals (FMOS) have also been determined. The chemical shielding anisotropic (CSA) parameters are calculated from the NMR analysis, Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

In vitro TAXOL production, by Pestalotiopsis breviseta--a first report.

PubMed

Kathiravan, Govindarajan; Sri Raman, Vithiyanathan

2010-09-01

Coelomycetous fungi were screened for the production of TAXOL. TAXOL production of Pestalotiopsis breviseta fungi is confirmed by Ultra Violet (UV) spectroscopic analysis, Infra Red (IR) analysis, high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and LC-MASS spectroscopy. TAXOL isolated from the P. breviseta fungus was identical with authentic TAXOL and produces 0.064 mg/L (0.128% dry weight of fungal mat). Copyright (c) 2010 Elsevier B.V. All rights reserved.

Theoretical study on the antitumor properties of Ru(II) complexes containing 2-pyridyl, 2-pyridine-4-carboxylic acid ligands

NASA Astrophysics Data System (ADS)

Erkan kariper, Sultan; Sayin, Koray; Karakaş, Duran

2017-12-01

[Ru(bipy)2(CppH)]2+(1), [Ru(bipy)2(Cpp-NH-Hex-COOH)]2+(2), [Ru(dppz)2(CppH)]2+(3) and [Ru(dppz)2(Cpp-NH-Hex-COOH)]2+(4) were calculated by Hartree-Fock (HF), Density Functional Theory (DFT) hybrid B3LYP and Moller-Plesset Perturbation (MPn n = 2,3) theory method and CEP-4G, CEP-31G, CEP-121G, LANL2DZ, LANL2MB, SDD basic sets and a mixed basic set with the keyword GEN in gas phase and water. Structure parameters obtained from optimized structures were compared with experimental parameters. M062X/(6-31G(d))(CEP-4G) level was taken into account for the most appropriate calculation level. IR, UV-VIS and NMR spectrums were examined for structural characterization. The optimal structure was identified via structure parameters, IR, UV-VIS and NMR spectrums. For the most compatible structure, the highest molecular orbital energy (EHOMO) which one of the most effective chemical determiners on the antitumor activity of the complexes, the lowest molecular orbital energy (ELUMO), LUMO-HOMO energy gap, hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity index (ω), molar volume (V), dipole moment (DM), total negative charge (TNC), enthalpy (H), entropy (S) and total energy (E) were calculated. The causes of anticancer activity of the complexes have been studied.

Preparation and characterizations of SnO2 nanopowder and spectroscopic (FT-IR, FT-Raman, UV-Visible and NMR) analysis using HF and DFT calculations.

PubMed

Ayeshamariam, A; Ramalingam, S; Bououdina, M; Jayachandran, M

2014-01-24

In this work, pure and singe phase SnO2 Nano powder is successfully prepared by simple sol-gel combustion route. The photo luminescence and XRD measurements are made and compared the geometrical parameters with calculated values. The FT-IR and FT-Raman spectra are recorded and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (LSDA, B3LYP and B3PW91) theory in bulk phase of SnO2 and are compared with its Nano phase. The vibrational frequency pattern in nano phase gets realigned and the frequencies are shifted up to higher region of spectra when compared with bulk phase. The NMR and UV-Visible spectra are simulated and analyzed. Transmittance studies showed that the HOMO-LUMO band gap (Kubo gap) is reduced from 3.47 eV to 3.04 eV while it is heated up to 800°C. The Photoluminescence spectra of SnO2 powder showed a peak shift towards lower energy side with the change of Kubo gap from 3.73 eV to 3.229 eV for as-prepared and heated up to 800°C. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Synthesis, characterization, computational studies and biological evaluation of S-benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate

NASA Astrophysics Data System (ADS)

Bhat, Rayees A.; Kumar, D.; Malla, Manzoor A.; Bhat, Sami U.; Khan, Md Shahzad; Manzoor, Ovais; Srivastava, Anurag; Naikoo, Rawoof A.; Mohsin, Mohd; Mir, Muzzaffar A.

2018-03-01

S-Benzyl-β-N-[3-(4-hydroxy-3-methoxy-phenylallylidene)]dithiocarbazate (HL1), Schiff base of S-benzyl dithiocarbazate, was synthesized by 1:1 condensation between S-benzyl dithiocarbazate and 4-hydroxy-3-methoxy cinnamaldehyde. The nitrogen-sulfur Schiff base (HL1) was characterized by Mass, FT-IR, H1-NMR, Raman, and UV-VIS spectroscopic techniques. Theoretical quantum chemical calculations were performed using DFT in combination with B3LYP exchange correlation functional and 6-311++ G (d, p) basis sets level. The calculated values of chemical potential (μ), HOMO-LUMO energy gap, chemical hardness, softness (S), ionization energy (IE), electron affinity (EA), dipole moment (D) and relative stabilization energy of the compound were 0.14881 eV, 0.12542 eV, 0.06271 eV, 3.37299 eV, -0.21152 eV, -0.08610 eV, 4.4090 Debye and -1753.350 eV respectively. Theoretically calculated parameters like H1-NMR, FT-IR, UV-VIS, Raman, electrostatic potential and HOMO-LUMO energy gap are in good agreement with experimental results. Also, in-vitro cytotoxicity studies were done against two habitually infection causing bacteria strains including gram-positive (S. aureus) and gram-negative (E. coli) for antibacterial activity. The results showed appreciable biological activity and the activity increased with increase in dose.

'Naked-eye' detection of biologically important anions in aqueous media by colorimetric receptor and its real life applications

NASA Astrophysics Data System (ADS)

Singh, Archana; Trivedi, Darshak R.

2017-05-01

A colorimetric receptor R 2-[(2-Hydroxy-naphthalen-1-ylmethylene)-hydrazonomethyl]-quinolin-8-ol has been designed and synthesized with good yield and characterized by the standard spectroscopic techniques such as FT-IR, UV-Visible, 1H NMR, 13C NMR and ESI-MS. The receptor R showed naked-eye detection and spectral change in the presence of F-, AcO- and H2PO4- over other anions. Interestingly, receptor R displaying high selective recognition towards F-, AcO- ion with a drastic color change from pale yellow to red in dry DMSO solvent and orange in mixed solvent DMSO/H2O (9:1, v/v). The behavior of receptor R towards F-, AcO- ion was investigated using UV-Vis and 1H NMR experiment. The detailed 1H NMR experiment result revealed that the receptor R is forming the hydrogen bonding between imine nitrogen and phenolic sbnd OH proton towards anions. The receptor R is able to detect sodium salts of flouride (NaF) and acetate (NaAcO) in aqueous medium and it exhibited dramatic color change from pale yellow to red. The receptor R demonstrated itself to be useful for real life application by detecting flouride and acetate ion in sea-water and commercially available product such as toothpaste, mouthwash and vinegar solution.

The Synthesis and Characterization of a Group of Transition Metal Octabutoxynaphthalocyanines and the Absorption and Emission Properties of the Co, Rh, Ir, Ni, Pd and Pt Members of This Group

PubMed Central

Kim, Junhwan; Soldatova, Alexandra V.; Rodgers, Michael A. J.; Kenney, Malcolm E.

2013-01-01

The synthesis and photophysical properties of new metallo-octabutoxynaphthalocyanines with Rh(III), Ir(III), and Pt(II) are reported. Various metals were inserted into the metal-free octabutoxynaphthalocyanine and the resultant metal complexes were fully characterized by NMR, UV-vis spectroscopy, and mass spectrometry. The absorption and emission properties of these new complexes were also examined and compared to those of Co(II), Ni(II), and Pd(II) octabutoxynaphthalocyanines. The results provide useful information to understand the effect of these transition metals on the properties of this macrocyclic ring. PMID:23745014

Spectroscopic characteristic (FT-IR, 1H, 13C NMR and UV-Vis) and theoretical calculations (MEP, DOS, HOMO-LUMO, PES, NBO analysis and keto-enol tautomerism) of new tetradentate N,N‧-bis(4-hydroxysalicylidene)-1,4-phenylenediamine ligand as chelating agent for the synthesis of dinuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes

NASA Astrophysics Data System (ADS)

Rajaei, Iman; Mirsattari, Seyed Nezamoddin

2018-07-01

The synthesis and characterization of a novel symmetrical Schiff base ligand N,Nʹ-bis(4-hydroxysalicylidene)-1,4-phenylenediamine (BHSP) was presented in this study and characterized by FT-IR, NMR (1H and 13C) and UV-Vis spectroscopy experimentally and theoretically. Also a series of binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of BHSP ligand have been synthesized by conventional sequential route in 1:1 equivalent of L:M ratio and characterized by routine physicochemical characterizations. The molecular geometry and vibrational frequencies of the BHSP in the ground state were calculated by using density functional theory (DFT) B3LYP method invoking 6-31G(d,p) and 6-31++G(d,p) basis sets. To study different conformations of the molecule, potential energy surface (PES) scan investigations were performed. The energetic behavior of the ligand compound (BHSP) in solvent media has been examined using B3LYP method with the 6-31G(d,p) and 6-31++G(d,p) basis sets by applying the polarized continuum model (PCM). In addition, DFT calculations of the BHSP ligand, molecular electrostatic potential (MEP), contour map, natural bond orbital (NBO) analysis, frontier molecular orbitals (FMO) analysis, NMR analysis and TD-DFT calculations were conducted. The calculated properties are in agreement with the available experimental data and closely related molecule BSP. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters.

Preparation and characterization of functional poly(vinylidene fluoride) (PVDF) membranes with ultraviolet-absorbing property

NASA Astrophysics Data System (ADS)

Dong, Li; Liu, Xiangdong; Xiong, Zhengrong; Sheng, Dekun; Lin, Changhong; Zhou, Yan; Yang, Yuming

2018-06-01

We first reported a strategy to prepare functional poly(vinylidene fluoride) (PVDF) membranes with excellent ultraviolet-absorbing property through chemically induced grafting. Herein, the polymerizable ultraviolet (UV) absorber 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) made by ourselves was grafted onto the PVDF chains that have been pretreated with tetraethylammonium hydroxide (TEAH) alkaline solution. Moreover, the effect of experiment conditions such as the alkali and monomer concentrations, alkali treatment time on the UV-absorbing property of the obtained PVDF-g-PBPMA membranes were studied in detail. The chemical structure of the modified membranes was confirmed by 1H NMR, FT-IR and XPS measurements. Meanwhile, the thermal and UV-absorbing properties were characterized by TGA, DSC and UV-Vis spectrophotometer, respectively. The results indicated that BPMA side chains were successfully introduced onto PVDF backbones. Most importantly, the obtained PVDF-g-PBPMA membranes exhibited excellent UV-absorbing property. The transmittance of UV light at 300 nm decreased to as low as 0.02% and the UV light below 388 nm could be completely absorbed by the PVDF-g-PBPMA membrane made under optimal condition.

Quantum mechanical and spectroscopic (FT-IR, 13C, 1H NMR and UV) investigations of 2-(5-(4-Chlorophenyl)-3-(pyridin-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole by DFT method

NASA Astrophysics Data System (ADS)

Diwaker

2014-07-01

The electronic, NMR, vibrational, structural properties of a new pyrazoline derivative: 2-(5-(4-Chlorophenyl)-3-(pyridine-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole has been studied using Gaussian 09 software package. Using VEDA 4 program we have reported the PED potential energy distribution of normal mode of vibrations of the title compound. We have also reported the 1H and 13C NMR chemical shifts of the title compound using B3LYP level of theory with 6-311++G(2d,2p) basis set. Using time dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, electronic spectrum of the title compound has been studied and reported. NBO analysis and MEP surface mapping has also been calculated and reported using ab initio methods.

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr; Uenver, H.

2013-01-15

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

Synthesis, spectroscopic investigation and theoretical studies of 2-((E)-(2-(2-cyanoacetyl)hydrazono)methyl)-4-((E)-phenyldiazenyl)phenyl methyl carbonate

NASA Astrophysics Data System (ADS)

Arokiasamy, A.; Manikandan, G.; Thanikachalam, V.; Gokula Krishnan, K.

2017-04-01

Synthesis and computational optimization studies have been carried out by Hartree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-31+G(d, p) basis set for 2-((E)-(2-(2-cyanoacetyl)hydrazono)methyl)-4-((E)-phenyldiazenyl)phenyl methyl carbonate (CHPMC). The stable configuration of CHPMC was confirmed theoretically by potential energy surface scan analysis. The complete vibrational assignments were performed on the basis of total energy distribution (TED) analysis. The vibrational properties studied by IR and Raman spectroscopic data complemented by quantum chemical calculations support the formation of intramolecular hydrogen bond. Furthermore, the UV-Vis spectra are interpreted in terms of TD-DFT quantum chemical calculations. The shapes of the simulated absorption spectra are in good agreement with the experimental data. The comparison between the experimental and theoretical values of FT-IR, FT-Raman vibrational spectra, NMR (1H and 13C) and UV-Vis spectra have also been discussed.

Bimetallic ruthenium complexes bridged by divinylphenylene bearing oligo(ethylene glycol)methylether: synthesis, (spectro)electrochemistry and the lithium cation effect.

PubMed

Tian, Li Yan; Liu, Yuan Mei; Tian, Guang-Xuan; Wu, Xiang Hua; Li, Zhen; Kou, Jun-Feng; Ou, Ya-Ping; Liu, Sheng Hua; Fu, Wen-Fu

2014-03-14

A series of 1,4-disubstituted ruthenium-vinyl complexes, (E,E)-[{(PMe3)3(CO)ClRu}2(μ-HC=CH-Ar-CH=CH)], in which the 1,4-diethenylphenylene bridge bears two oligo(ethylene glycol)methyl ether side chains at different positions (2,5- and 2,3-positions), were prepared. The respective products were characterized by elemental analyses and NMR spectroscopy. The structures of complexes 1b and 1e were established by X-ray crystallography. The electronic properties of the complexes were investigated by cyclic voltammetry, and IR and UV-vis/NIR spectroscopies. Electrochemical studies showed that the 2,5-substituents better stabilized the mixed-valence states; the electrochemical behavior was greatly affected by lithium cations, especially complex 1g with 2,3-substituents, which was further supported by IR and UV-vis/NIR spectra changes. Spectroelectrochemical studies showed that the redox chemistry was dominated by the non-innocent character of the bridging fragment.

Synthesis, characterization, and pharmacological studies of ferrocene-1H-1,2,3-triazole hybrids

NASA Astrophysics Data System (ADS)

Haque, Ashanul; Hsieh, Ming-Fa; Hassan, Syed Imran; Haque Faizi, Md. Serajul; Saha, Anannya; Dege, Necmi; Rather, Jahangir Ahmad; Khan, Muhammad S.

2017-10-01

A series of ferrocene-1H-1,2,3-triazole hybrids namely 1-(4-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (1), 1-(4,4‧-dinitro-2-biphenyl)-4-ferrocenyl-1H-1,2,3-triazole (2), 1-(3-chloro-4-fluorophenyl)-4-ferrocenyl-1H-1,2,3-triazole (3), 1-(4-bromophenyl)-4-ferrocenyl-1H-1,2,3-triazole (4) and 1-(2-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (5) were designed and synthesized by copper-catalyzed azide alkyne cycloaddition (CuAAC) reaction. All the new hybrids were characterized by microanalyses, NMR (1H and 13C), UV-vis, IR, ESI-MS and electrochemical techniques. Crystal structure of the compound (3) was solved by single crystal X-ray diffraction method. The structural (single crystal) and spectroscopic (UV-Vis. and IR) properties of the compound 3 have been analyzed and compared by complementary quantum modeling. Hybrids 1-5 exhibited low toxicity and demonstrated neuroprotective effect.

Efficient Synthesis of Ir-Polyoxometalate Cluster Using a Continuous Flow Apparatus and STM Investigation of Its Coassembly Behavior on HOPG Surface.

PubMed

Zhang, Junyong; Chang, Shaoqing; Suryanto, Bryan H R; Gong, Chunhua; Zeng, Xianghua; Zhao, Chuan; Zeng, Qingdao; Xie, Jingli

2016-06-06

Taking advantage of a continuous-flow apparatus, the iridium(III)-containing polytungstate cluster K12Na2H2[Ir2Cl8P2W20O72]·37H2O (1) was obtained in a reasonable yield (13% based on IrCl3·H2O). Compound 1 was characterized by Fourier transform IR, UV-visible, (31)P NMR, electrospray ionization mass spectrometry (ESI-MS), and thermogravimetric analysis measurements. (31)P NMR, ESI-MS, and elemental analysis all indicated 1 was a new polytungstate cluster compared with the reported K14[(IrCl4)KP2W20O72] compound. Intriguingly, the successful isolation of 1 relied on the custom-built flow apparatus, demonstrating the uniqueness of continuous-flow chemistry to achieve crystalline materials. The catalytic properties of 1 were assessed by investigating the activity on catalyzing the electro-oxidation of ruthenium tris-2,2'-bipyridine [Ru(bpy)3](2+/3+). The voltammetric behavior suggested a coupled catalytic behavior between [Ru(bpy)3](3+/2+) and 1. Furthermore, on the highly oriented pyrolytic graphite surface, 1,3,5-tris(10-carboxydecyloxy) benzene (TCDB) was used as the two-dimensional host network to coassemble cluster 1; the surface morphology was observed by scanning tunneling microscope technique. "S"-shape of 1 was observed, indicating that the cluster could be accommodated in the cavity formed by two TCDB host molecules, leading to a TCDB/cluster binary structure.

Experimental and theoretical studies of a pyrazole-thiazolidin-2,4-di-one hybrid

NASA Astrophysics Data System (ADS)

Mushtaque, Md.; Avecilla, Fernando; Haque, Ashanul; Perwez, Ahmad; Khan, Md. Shahzad; Rizvi, M. Moshahid Alam

2017-08-01

The present work describes synthesis, characterization and biological evaluations of a hybrid compound 10 composed of two intriguing scaffolds pyrazole and thiazolidin-2,4-di-one. The title compound was obtained via multi-step reaction and characterized by a number of techniques (viz. IR, UV-Visible, 1H-NMR, 13C-NMR and MS) including X-ray crystallography. The structural and photophysical data of compound 10 were well supported by theoretical calculations performed at density functional (DFT) level. In-vitro anticancer studies on different human cancer cell lines indicated moderate to low activity of the compounds. The molecular target of the compound was predicted through in-silico studies. Finding of the studies are presented herein.

Synthesis, spectral features and biological activity of some novel hetarylazo dyes derived from 6-amino-1,3-dimethyluracil

NASA Astrophysics Data System (ADS)

Yousefi, Hessamoddin; Yahyazadeh, Asieh; Yazdanbakhsh, Mohammad Reza; Rassa, Mehdi; Moradi-e-Rufchahi, Enayat O.'llah

2012-05-01

A series of hetarylazoaminouracil dyes were prepared by coupling of 6-amino-1,3-dimethyluracil with eight diazotized heterocyclic amines in nitrosyl sulphuric acid. The prepared azo dyes were characterized by UV-Vis, FT-IR, 13C NMR, 1H NMR spectroscopic techniques and elemental analysis. The solvatochromism of dyes was evaluated with respect to wavelength of maximum absorption (λmax) in seven solvents with different polarities: acetic acid, methanol, water, chloroform, acetonitrile, dimethyl sulfoxide and dimethyl formamide. The effects of acid, base and concentration of the dye on the visible absorption spectra were also reported. In addition, the antimicrobial activity of the synthesized dyes was evaluated on Escherichia coli, Bacillus subtilis, Micrococcus leuteus and Pseudomonas aeruginosa.

Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: synthesis, spectral characterization, antimicrobial and nuclease studies.

PubMed

Subbaraj, P; Ramu, A; Raman, N; Dharmaraja, J

2014-01-03

A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA=Schiff base and B=2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, (1)H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, (1)H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique. Copyright © 2013 Elsevier B.V. All rights reserved.

[Study on the chemical constituents in roots of Gentiana dahurica].

PubMed

Chen, Qian-Liang; Shi, Zhang-Yan; Zhang, Ya-Hui; Zheng, Jiang-Bin

2011-08-01

To systematically study the chemical constituents in the roots of Gentiana dahurica. Various column chromatographic techniques were used for isolation and purification. The structures were elucidated on the basis of spectral data (UV, IR, MS, NMR) and identified by comparing with the authentic substance. Seven compounds were isolated and identified as: roburic acid (1), oleanolic acid (2), beta-sitosterol (3), daucosterol (4), gentiopicroside(5), swertiamarine (6), sweroside (7). Compounds 1, 2 and 4 are isolated from this plant for the first time.

Janthinocins A, B and C, novel peptide lactone antibiotics produced by Janthinobacterium lividum. I. Taxonomy, fermentation, isolation, physico-chemical and biological characterization.

PubMed

O'Sullivan, J; McCullough, J; Johnson, J H; Bonner, D P; Clark, J C; Dean, L; Trejo, W H

1990-08-01

Janthinocins A, B and C are novel antibacterial agents produced by Janthinobacterium lividum. They were isolated from fermentation broths and characterized by UV, IR, NMR and mass spectroscopy. They are cyclic decapeptide lactones with marked activity against aerobic and anaerobic Gram-positive bacteria and are 2 to 4 times more potent in vitro than vancomycin. Janthinocins A and B were also found to be effective in a Staphylococcus aureus systemic infection in mice.

Limonoid from the rhizomes of Luvunga scandens (Roxb.) Buch. Ham.

PubMed

Nguyen, Tan Phat; Minh, Nhat Phan; Dat, Trong Bui; Le, Tien Dung; Tran Nguyen, Minh An; Pham, Thi Nhat Trinh; Tri, Dinh Mai

2017-10-01

For first time, the chemical constituents of the rhizomes of Luvunga scandens (Roxb.) Buch. Ham. were investigated and led to the isolation of one new limonoid named Luvunga A (1), together with seven known compounds, including one limonoid (2) and six coumarins (3-8) were isolated for the first time from the species L. scandens by various chromatography methods. Their chemical structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and compared with literatures.

Two new compounds from the fruits of Arctium lappa.

PubMed

He, Jun; Huang, Xiao-Ying; Yang, Ya-Nan; Feng, Zi-Ming; Jiang, Jian-Shuang; Zhang, Pei-Cheng

2016-05-01

Phytochemical investigation of the extract of Arctii Fructus led to the isolation and characterization of two new compounds, named arctiisesquineolignan B (1) and arctiiphenolglycoside A (2). Their structures were elucidated by means of spectroscopic methods (UV, IR, HR-ESI-MS, 1D and 2D NMR) and chemical evidence, as well as by comparison with known analogs in the literature. Compound 2 exhibited stronger antioxidant activity than the positive control ascorbic acid at a concentration of 10 μM.

Spectral analysis, vibrational assignments, NBO analysis, NMR, UV-Vis, hyperpolarizability analysis of 2-aminofluorene by density functional theory.

PubMed

Jone Pradeepa, S; Sundaraganesan, N

2014-05-05

In this present investigation, the collective experimental and theoretical study on molecular structure, vibrational analysis and NBO analysis has been reported for 2-aminofluorene. FT-IR spectrum was recorded in the range 4000-400 cm(-1). FT-Raman spectrum was recorded in the range 4000-50 cm(-1). The molecular geometry, vibrational spectra, and natural bond orbital analysis (NBO) were calculated for 2-aminofluorene using Density Functional Theory (DFT) based on B3LYP/6-31G(d,p) model chemistry. (13)C and (1)H NMR chemical shifts of 2-aminofluorene were calculated using GIAO method. The computed vibrational and NMR spectra were compared with the experimental results. The total energy distribution (TED) was derived to deepen the understanding of different modes of vibrations contributed by respective wavenumber. The experimental UV-Vis spectra was recorded in the region of 400-200 nm and correlated with simulated spectra by suitably solvated B3LYP/6-31G(d,p) model. The HOMO-LUMO energies were measured with time dependent DFT approach. The nonlinearity of the title compound was confirmed by hyperpolarizabilty examination. Using theoretical calculation Molecular Electrostatic Potential (MEP) was investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO) studies on pyrrole-isonicotinyl hydrazine

NASA Astrophysics Data System (ADS)

Rawat, Poonam; Singh, R. N.; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

2017-05-01

As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7 kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, 1H NMR, 13C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π → π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89 × 10- 30 esu, (gas phase); 68.79 × 10- 30 (CHCl3), esu; 76.76 × 10- 30 esu (CH2Cl2), 85.16 × 10- 30 esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram-positive bacteria Bacillus subtilis, respectively. The compound also shows good antituberculosis activity against Mycobacterium tuberculosis H37Rv using the microplate alamar blue assay (MABA).

Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations

NASA Astrophysics Data System (ADS)

Karthikeyan, N.; Joseph Prince, J.; Ramalingam, S.; Periandy, S.

2015-05-01

In the present research work, the FT-IR, FT-Raman and 13C and 1H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, 13C NMR and 1H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed.

Study on the interaction of triadimenol with calf thymus DNA by multispectroscopic methods and molecular modeling

NASA Astrophysics Data System (ADS)

Zhang, Yepeng; Zhang, Guowen; Fu, Peng; Ma, Yadi; Zhou, Jia

2012-10-01

The binding mechanism of triadimenol (NOL) to calf thymus DNA (ctDNA) in physiological buffer (pH 7.4) was investigated by multispectroscopic methods including UV-vis absorption, fluorescence, circular dichroism (CD), Fourier transform infrared (FT-IR), and nuclear magnetic resonance (1H NMR) spectroscopy, coupled with viscosity measurements and atomic force microscopy (AFM) technique. The results suggested that NOL interacted with ctDNA by intercalation mode. CD and AFM assays showed that NOL can damage the base stacking of ctDNA and result in regional cleavage of the two DNA strands. FT-IR and 1H NMR spectra coupled with molecular docking revealed that a specific binding mainly exists between NOL and G-C base pairs of the ctDNA where two hydrogen bonds form. Moreover, the association constants of NOL with DNA at three different temperatures were determined to be in the 103 L mol-1 range. The calculated thermodynamic parameters suggested that the binding of NOL to ctDNA was driven mainly by hydrogen bond and van der Waals.

Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

NASA Astrophysics Data System (ADS)

Boghaei, Davar M.; Gharagozlou, Mehrnaz

2007-07-01

A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

Optoelectronic and photoacoustic studies of an organic dye synthesized through green route

NASA Astrophysics Data System (ADS)

Vijayakumar, S.; Sreelatha, S.; Hatamimoslehabadi, M.; Yelleswarappu, C. S.

2017-10-01

An azo dye was prepared through an environmentally benign and economically feasible synthesis route with cardanol as a starting material. Cardanol is a cost-effective and renewable natural source obtained from Cashew Nut Shell Liquid, a by-product of the cashew industry. The dye was spectrally characterized by IR, UV-Vis, NMR and fluorescence studies. UV-Vis absorption showed a bathochromic shift between solvents of lower and higher polarities. Nonlinear optical and photoacoustic properties were studied using a frequency doubled Nd:YAG laser producing 532 nm laser pulses of 3 ns pulse width. Results show that the nonlinear absorption coefficient decreases with the increase of on-axis intensity, suggesting excited state absorption as the principal mechanism. The observed nonlinearity has applications in optoelectronics.

New 1,3,4-thiadiazole compounds including pyrazine moiety: Synthesis, structural properties and antimicrobial features

NASA Astrophysics Data System (ADS)

Gür, Mahmut; Şener, Nesrin; Muğlu, Halit; Çavuş, M. Serdar; Özkan, Osman Emre; Kandemirli, Fatma; Şener, İzzet

2017-07-01

In the study, some new 1,3,4-thiadiazole compounds were synthesized and we have reported identification of the structures by using UV-Vis, FT-IR, 1H NMR, 13C NMR and Mass spectroscopic methods. Antimicrobial activities of the compounds against three microorganisms, namely, Candida albicans ATCC 26555, Staphylococcus aureus ATCC 9144, and Escherichia coli ATCC 25922 were investigated by using disk diffusion method. These thiadiazoles exhibited an antimicrobial activity against Staphylococcus aureus and Candida albicans. The experimental data was supported by the quantum chemical calculations. Density functional theory (DFT) calculations were carried out to obtain the ground state optimized geometries of the molecules using the B3LYP, M06 and PBE1PBE methods with 3-21 g, 4-31 g, 6-311++g(2d,2p), cc-pvtz and cc-pvqz basis sets in the different combinations. Frontier molecular orbitals (FMOs) energies, band gap energies and some chemical reactivity parameters were calculated by using the aforementioned methods and basis sets, and the results were also compared with the experimental UV-Vis data.

Synthesis, spectral characterization and DNA binding of Schiff-base metal complexes derived from 2-amino-3-hydroxyprobanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2014-11-01

Four new metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H3L) resulted from the condensation of the amino acid 2-amino-3-hydroxyprobanoic acid (serine) and acetylacetone have been synthesized and characterized by, elemental analyses, ES-MS, IR, UV-Vis., 1H NMR, 13C NMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that the Schiff-base ligand acts as bi-negative tridentate through the azomethine nitrogen, the deprotonated carboxylate oxygen and the enolic carbonyl oxygen. The optical band gaps measurements indicated the semi-conducting nature of these complexes. Molecular docking was used to predict the binding between the Schiff base ligand with the receptor of prostate cancer mutant H874Y. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA in an intercalative mode.

Second-sphere coordination in anion binding: Synthesis, characterization and X-ray structures of bis(diethylenetriamine)cobalt(III) complexes containing benzoates

NASA Astrophysics Data System (ADS)

Bala, Ritu; Kaur, Amrinder; Kashyap, Monika; Janzen, Daron E.

2014-04-01

New complexes of composition s-fac-[Co(dien)2]Cl2(Bz)·H2O (1), s-fac-[Co(dien)2]Cl(p-CBz)2·4.5H2O (2) and mer-[Co(dien)2](p-NBz)3·3H2O (3) were obtained by reacting aqueous solutions of bis(diethylenetriamine)cobalt(III) chloride and sodium salts of benzoates ((Bz = benzoate, CBz = p-chlorobenzoate, NBz = p-nitrobenzoate)) in 1:3 molar ratio. These complexes were characterized by TG analysis and spectroscopic studies (IR, NMR and UV-vis). IR and NMR studies were used for the isomeric identification of [Co(dien)2]3+ in new complexes. This cation, contains ligand diethylenetriamine (dien) bearing H-bond donors, capable of forming hydrogen bonds and its binding properties with benzoates have been studied using standard UV-vis spectroscopic titrations in aqueous medium (log k for Bz = 2.11, p-CBz = 3.64 and p-NBz = 3.66). Single crystal X-ray study of complex 2 and 3 reveals that both the structures are dominantly stabilized by second-sphere coordination through H-bonding interactions of type-NH (dien)⋯O (benzoates) and H (water)⋯O (benzoates) in addition to the electrostatic forces of attractions. Further, the NH (dien)⋯Cl- (counter ion) and NH (dien)⋯O (water) types of interactions are also playing a dominant role to stabilize the crystal lattice in complex 2 and 3 respectively.

A comparative experimental and quantum chemical study on monomeric and dimeric structures of 3,5-dibromoanthranilic acid.

PubMed

Karabacak, Mehmet; Cinar, Mehmet

2012-10-01

This study presents the structural and spectroscopic characterization of 3,5-dibromoanthranilic acid with help of experimental techniques (FT-IR, FT-Raman, UV, NMR) and quantum chemical calculations. The vibrational spectra of title compound were recorded in solid state with FT-IR and FT-Raman in the range of 4000-400 and 4000-50 cm(-1), respectively. The vibrational frequencies were also computed using B3LYP method of DFT with 6-311++G(d,p) basis set. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The (1)H, (13)C and DEPT NMR spectra were recorded in DMSO solution and calculated by gauge-invariant atomic orbitals (GIAO) method. The UV absorption spectra of the compound were recorded in the range of 200-400 nm in ethanol, water and DMSO solutions. Solvent effects were calculated using time-dependent density functional theory and CIS method. The ground state geometrical structure of compound was predicted by B3LYP method and compared with the crystallographic structure of similar compounds. All calculations were made for monomeric and dimeric structure of compound. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken atomic charges of neutral and anionic form of the molecule were computed and compared with anthranilic acid. Copyright © 2012 Elsevier B.V. All rights reserved.

Investigation of structure, vibrational and NMR spectra of oxycodone and naltrexone: A combined experimental and theoretical study

NASA Astrophysics Data System (ADS)

Tavakol, Hossein; Esfandyari, Maryam; Taheri, Salman; Heydari, Akbar

2011-08-01

In this work, two important opioid antagonists, naltrexone and oxycodone, were prepared from thebaine and were characterized by IR, 1H NMR and 13C NMR spectroscopy. Moreover, computational NMR and IR parameters were obtained using density functional theory (DFT) at B3LYP/6-311++G** level of theory. Complete NMR and vibrational assignment were carried out using the observed and calculated spectra. The IR frequencies and NMR chemical shifts, determined experimentally, were compared with those obtained theoretically from DFT calculations, showed good agreements. The RMS errors observed between experimental and calculated data for the IR absorptions are 85 and 105 cm -1, for the 1H NMR peaks are 0.87 and 0.17 ppm and for those of 13C NMR are 5.6 and 5.3 ppm, respectively for naltrexone and oxycodone.

Synthesis of copolymers containing diazoketo groups and their application as DUV resists

NASA Astrophysics Data System (ADS)

Kim, Jin-Baek; Kim, Kyoung-Seon

2005-05-01

We synthesized a new type of polymers that have diazoketo groups instead of acid-labile protecting groups. The polymers do not need a photoacid generator for formulation of resists. That is, the new matrix polymers absorb UV light and produce carboxylic groups. Also, there is no necessity for a post-exposure bake step, which is the cause of post-exposure delay effects. New monomer, ethyl 2-diazo-4-methyl-3-oxo-pent-4-enoate was synthesized. This monomer was copolymerized with hydroxystyrene and adamantyl methacrylate. After UV exposure, the polymers became soluble in an aqueous base developer. The polymers showed bleaching effect after UV exposure. Thermal properties of the polymers were measured by TGA and DSC. Characterization of the polymers has been done using other techniques such as FT-IR, NMR, GPC, and UV. The resist patterns of 0.8 μm feature size were resolved using a DUV contact printer and with a tetramethylammonium hydroxide aqueous solution.

Bringing NMR and IR Spectroscopy to High Schools

ERIC Educational Resources Information Center

Bonjour, Jessica L.; Hass, Alisa L.; Pollock, David W.; Huebner, Aaron; Frost, John A.

2017-01-01

Development of benchtop, portable Fourier transform nuclear magnetic resonance (NMR) and infrared (IR) spectrometers has opened up opportunities for creating university-high school partnerships that provide high school students with hands-on experience with NMR and IR instruments. With recent changes to the international baccalaureate chemistry…

Twilight zone sponges from Guam yield theonellin isocyanate and psammaplysins I and J.

PubMed

Wright, Anthony D; Schupp, Peter J; Schrör, Jan-Philipp; Engemann, Anna; Rohde, Sven; Kelman, Dovi; de Voogd, Nicole; Carroll, Anthony; Motti, Cherie A

2012-03-23

From the organic extracts of two Guam sponges, Rhaphoxya sp. and Suberea sp., determined to have cytotoxic and chemopreventive activities, three new compounds, theonellin isocyanate (1) and psammaplysins I and J (5, 6), and six previously reported compounds (2-4, 7-9) were isolated and characterized spectroscopically ((1)H and (13)C NMR, MS, IR, UV, [α](D)). The two new metabolites (5 and 6) isolated from the Suberea sp. sponge are rare examples of compounds containing a bromotyramine moiety rather than the more usual dibromo analogue. For the compounds isolated from the Rhaphoxya sp., this is the first report of the known compounds 2-4 being found in a single sponge. For previously reported compounds 2-4 complete unambiguous (1)H and (13)C NMR data are provided.

Synthesis, characterization and fluorescent properties of water-soluble glycopolymer bearing curcumin pendant residues.

PubMed

Zhang, Haisong; Yu, Meng; Zhang, Hailei; Bai, Libin; Wu, Yonggang; Wang, Sujuan; Ba, Xinwu

2016-08-01

Curcumin is a potential natural anticancer drug with low oral bioavailability because of poor water solubility. The aqueous solubility of curcumin is enhanced by means of modification with the carbohydrate units. Polymerization of the curcumin-containing monomer with carbohydrate-containing monomer gives the water-soluble glycopolymer bearing curcumin pendant residues. The obtained copolymers (P1 and P2) having desirable water solubility were well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV-Vis absorption spectroscopy, and photoluminescence spectroscopy. The copolymer P2 with a molar ratio of 1:6 (curcumin/carbohydrate) calculated from the proton NMR results exhibits a similar anticancer activity compared to original curcumin, which may serve as a potential chemotherapeutic agent in the field of anticancer medicine.

Synthesis, characterization and spectroscopic behavior of novel 2-oxo-1,4-disubstituted-1,2,5,6-tetrahydrobenzo[h]quinoline-3-carbonitrile dyes.

PubMed

Khan, Salman A; Asiri, Abdullah M; Al-Thaqafy, Saad H; Faidallah, Hassan M; El-Daly, Samy A

2014-12-10

Two synthetic pathways were adopted to synthesize the target 2-oxo-1,4-disubstituted-1,2,5,6-tetrahydro-benzo[h]quinoline-3-carbonitriles. Structure of the synthesized compounds has been characterized based on FT-IR, (1)H NMR, (13)C NMR and elemental analyses. UV-Vis and fluorescence spectroscopy measurements provided that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including singlet absorption, extinction coefficient, Stokes shift, oscillator strength and dipole moment were investigated in order to explore the analytical potential of synthesized compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Phytochemical Investigations on Chemical Constituents of Achillea tenuifolia Lam

PubMed Central

Moradkhani, Shirin; Kobarfard, Farzad; Ayatollahi, Seyed Abdol Majid

2014-01-01

Achillea tenuifolia Lam. (Asteraceae) afforded a methanolic extract from which after fractionation in solvents with different polarities, two known flavones 3’, 5- dihydroxy- 4’, 6, 7- trimethoxy flavone (eupatorine, compound 3), 5- hydroxy- 3’,4’, 6, 7- tetramethoxyflavone (compound 4), besides stearic acid (compound 1), lupeol (compound 2), daucosterol (β- sitosterol 3-O- β- D- glucopyranoside, compound 5), 2, 4- dihydroxy methyl benzoate (compound 6) were isolated for the first time. The structure of isolated compounds was elucidated by means of different spectroscopic methods such as UV, IR, Mass and 1H- NMR (1D and 2D) and 13C-NMR. For further confirming the structures of isolated compounds, comparison of the spectral data of them with those reported in the litratures have been done. PMID:25276207

Antidepressent Effect of Two New Benzyl Derivatives from Wild Strawberry Fragaria vesca var. nubicola Lindl. ex Hook.f.

PubMed

Naz, Sadia; Farooq, Umar; Khan, Ajmal; Khan, Haroon; Karim, Nasiara; Sarwar, Rizwana; Hussain, Javid; Rauf, Abdur

2017-01-01

Two new benzyl derivatives were isolated from ethyl acetate fraction of wild strawberry, Fragaria vesca var. nubicola Lindl. ex Hook.f. The structures of these compounds were elucidated to be 5-(4-hydroxy-3-methoxyphenethyl)-7-methoxy-2H-chromen-3-ol ( 1 ) and 5-(4-hydroxy-3-methoxyphenethyl)-4,7-dimethoxy-2H-chromen-3-ol ( 2 ) based on spectroscopic data through IR, UV, 1 H-NMR, 13 C-NMR along with two dimensional (2D) techniques HMBC, HMQC, and COSY. Both compounds 1 and 2 were studied in tail suspension and forced swim tests for antidepressant like effects. A significant dose dependent antidepressant like effect was observed by causing spontaneous anti-immobility at various test doses upon intraperitoneal administration.

Borrelidins C-E: New Antibacterial Macrolides from a Saltern-Derived Halophilic Nocardiopsis sp.

PubMed

Kim, Jungwoo; Shin, Daniel; Kim, Seong-Hwan; Park, Wanki; Shin, Yoonho; Kim, Won Kyung; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Oh, Dong-Chan

2017-06-06

Chemical investigation of a halophilic actinomycete strain belonging to the genus Nocardiopsis inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins C-E ( 1 - 3 ), along with a previously reported borrelidin ( 4 ). The planar structures of borrelidins C-E, which are new members of the rare borrelidin class of antibiotics, were elucidated by NMR, mass, IR, and UV spectroscopic analyses. The configurations of borrelidines C-E were determined by the interpretation of ROESY NMR spectra, J-based configuration analysis, a modified Mosher's method, and CD spectroscopic analysis. Borrelidins C and D displayed inhibitory activity, particularly against the Gram-negative pathogen Salmonella enterica , and moderate cytotoxicity against the SNU638 and K562 carcinoma cell lines.

Unprecedented 22,26-seco physalins from Physalis angulata and their anti-inflammatory potential.

PubMed

Sun, Cheng-Peng; Oppong, Mahmood Brobbey; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

2017-10-25

Two novel physalins, including a 22,26-seco physalin, physalin X (1), and a 11,15-cyclo-9(10),14(17),22(26)-triseco physalin with an unprecedented aromatic ring, aromaphysalin B (2), were isolated from Physalis angulata L. Their structures were determined by IR, UV, HRESIMS, and 2D NMR spectra as well as theoretical calculations. Compounds 1 and 2 exhibited inhibitory activities on NO production with IC 50 values of 68.50 and 29.69 μM, respectively. A plausible biosynthetic pathway for 2 is also discussed.

A new p-hydroxybenzoic acid derivative from an endophytic fungus Penicillium sp. of Nerium indicum.

PubMed

Ma, Yang-Min; Qiao, Ke; Kong, Yang; Guo, Lin-Xin; Li, Meng-Yun; Fan, Chao

2017-12-01

A new p-hydroxybenzoic acid derivative named 4-(2'R, 4'-dihydroxybutoxy) benzoic acid (1) was isolated from the fermentation of Penicillium sp. R22 in Nerium indicum. The structure was elucidated by means of spectroscopic (HR-ESI-MS, NMR, IR, UV) and X-ray crystallographic methods. The antibacterial and antifungal activity of compound 1 was tested, and the results showed that compound 1 revealed potent antifungal activity against Colletotrichum gloeosporioides, Alternaria alternata, and Alteranria brassicae with MIC value of 31.2 μg/ml.

Synthesis and Characterization of Rhodamine B-ethylenediamine-hyaluronan Acid as Potential Biological Functional Materials

NASA Astrophysics Data System (ADS)

Li, Y. L.; Wang, W. X.; Wang, Y.; Zhang, W. B.; Gong, H. M.; Liu, M. X.

2018-05-01

The purpose of this study is to synthesize and characterize fluorescent polymers, rhodamine B-ethylenediamine-hyaluronan acid (RhB-EA-HA). RhB-EA-HA was successfully synthesized by ester ammonolysis reaction and amidation reaction. Moreover, the structural properties of RhB-EA-HA were characterized by 1H-NMR spectra, UV-vis spectrometry and Fourier transform infrared spectroscopy (FT-IR). RhB-EA-HA can be grafted on the surface of silica nanomaterials, which may be potential biological functional materials for drug delivery system.

New cholinesterase inhibitors from Garcinia atroviridis.

PubMed

Tan, Wen-Nee; Khairuddean, Melati; Wong, Keng-Chong; Khaw, Kooi-Yeong; Vikneswaran, Murugaiyah

2014-09-01

A triflavanone, Garcineflavanone A (1) and a biflavonol, Garcineflavonol A (2) have been isolated from the stem bark of Garcinia atroviridis (Clusiaceae), collected in Peninsular Malaysia. Their structures were established using one and two-dimensional NMR, UV, IR and mass spectrometry and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Molecular docking studies of the isolated compounds were performed using docking procedure of AutoDock to disclose the binding interaction and orientation of these molecules into the active site gorge. Copyright © 2014 Elsevier B.V. All rights reserved.

Pyrrole based Schiff bases as colorimetric and fluorescent chemosensors for fluoride and hydroxide anions.

PubMed

Velmathi, Sivan; Reena, Vijayaraghavan; Suganya, Sivalingam; Anandan, Sambandam

2012-01-01

An efficient colorimetric sensor with pyrrole-NH moiety as binding site and nitro group as a signaling unit has been synthesized by a one step procedure and characterized by spectroscopic techniques, which displays excellent selectivity and sensitivity for fluoride and hydroxide ions. The hydrogen bonding with these anions provides remarkable colorimetric responses. (1)H NMR and FT IR studies has been carried out to confirm the hydrogen bonding. UV-vis and fluorescence spectral changes can be exploited for real time and on site application.

Computational study of some fluoroquinolones: Structural, spectral and docking investigations

NASA Astrophysics Data System (ADS)

Sayin, Koray; Karakaş, Duran; Kariper, Sultan Erkan; Sayin, Tuba Alagöz

2018-03-01

Quantum chemical calculations are performed over norfloxacin, tosufloxacin and levofloxacin. The most stable structures for each molecule are determined by thermodynamic parameters. Then the best level for calculations is determined by benchmark analysis. M062X/6-31 + G(d) level is used in calculations. IR, UV-VIS and NMR spectrum are calculated and examined in detail. Some quantum chemical parameters are calculated and the tendency of activity is recommended. Additionally, molecular docking calculations are performed between related compounds and a protein (ID: 2J9N).

Antimicrobial Evaluation of Mangiferin Analogues

PubMed Central

Singh, S. K.; Kumar, Y.; Kumar, S. Sadish; Sharma, V. K.; Dua, K.; Samad, A.

2009-01-01

The naturally occurring xanthone glycoside mangiferin has been isolated by column chromatography from the ethanol extract of stem bark of Mangifera indica. Mangiferin was further converted to 5-(N-phenylaminomethyleno)mangiferin, 5-(N-p-chlorophenylaminomethyleno) mangiferin, 5-(N-2-methylphenylaminomethyleno) mangiferin, 5-(N-p-methoxyphenylaminomethyleno) mangiferin, 5-(N, N-diphenylaminomethyleno) mangiferin, 5-(N--napthylaminomethyleno) mangiferin and 5-(N-4-methylphenylaminomethyleno) mangiferin. Mangiferin and its analogues were characterized by melting point and Rf value determination and through spectral technique like UV, IR, and NMR spectral analysis. The synthesized compounds were screened for antimicrobial activity. PMID:20490307

Photophysical, electrochemical, thermal and aggregation properties of new metal phthalocyanines

NASA Astrophysics Data System (ADS)

Jeong, Jaemyeng; Kumar, Rangaraju Satish; Mergu, Naveen; Son, Young-A.

2017-11-01

In this study, the synthesis of di(ethylene glycol) naphthalene substituted metal-phthalocyanines was reported. These novel phthalocyanines were characterized by elemental and spectroscopic analysis, including 1H NMR, FT-IR, UV-Vis spectral and MALDI-TOF mass data. The aggregation behavior of these phthalocyanines was examined in chloroform at different concentrations, and we confirmed that the phthalocyanines were non-aggregated. Further thermal stability, electrochemical, theoretical studies and metal sensing properties also investigated. In addition, we successfully prepared phthalocyanine (6d) blended polyurethane electrospun (ES) nanofibers.

Keto-enol tautomerism of (E)-2-[(3,4-dimethylphenylimino)methyl]-4-nitrophenol: Synthesis, X-ray, FT-IR, UV-Vis, NMR and quantum chemical characterizations

NASA Astrophysics Data System (ADS)

Özek Yıldırım, Arzu; Yıldırım, M. Hakkı; Albayrak Kaştaş, Çiǧdem

2017-01-01

(E)-2-((3,4-dimethylphenylimino)methyl)-4-nitrophenol, which is a new Schiff base compound, was synthesized and characterized by experimental and computational methods. Molecular geometry, harmonic oscillator model of aromaticity (HOMA) indices, intra- and inter-molecular interactions in the crystal structure were determined by using single crystal X-ray diffraction technique. The optimized structures, which are obtained by Gaussian and Slater type orbitals, were compared to experimental structures to determine how much correlation is found between the experimental and the calculated properties. Intramolecular and hyperconjugative interactions of bonds have been found by Natural Bond Orbital analysis. The experimental infrared spectrum of the compound has been analyzed in detail by the calculated infrared spectra and Potential Energy Distribution analysis. To find out about the correlation between the solvent polarity and the enol-keto equilibrium, experimental UV-Visible spectra of the compound were obtained in benzene, CHCl3, EtOH and DMSO solvents. In these solvents, the UV-Vis spectra and relaxed potential energy surface scan (PES) calculations have been performed to get more insight into the equilibrium dynamics. Solvent effects in UV-Vis and PES calculations have been taken into account by using Polarizable Continuum Modelling method. 1H and 13C NMR spectra of the compound (in DMSO) were analyzed. The computational study of nonlinear optical properties shows that the compound can be used for the development of nonlinear optical materials.

Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV-Visible), Fukui function, antimicrobial and molecular docking study of (E)-1-(3-bromobenzylidene)semicarbazide by DFT method

NASA Astrophysics Data System (ADS)

Raja, M.; Raj Muhamed, R.; Muthu, S.; Suresh, M.; Muthu, K.

2017-02-01

The title compound, (E)-1-(3-bromobenzylidene)semicarbazide (3BSC) was synthesized and characterized by FT-IR, FT-Raman, UV, 1HNMR and 13CNMR spectral analysis. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and the Raman scattering activities were calculated by using density functional theory (DFT) B3LYP method with 6-311++G(d,p) basis set. The calculated HOMO and LUMO energies show that charge transfer within the molecule. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). The hyperpolarizability calculation reveals the present material has a reasonably good propensity for nonlinear optical activity. Molecular electrostatic potential (MEP) and Fukui functions were also performed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the 3BSC at different temperatures have been calculated. The biological applications of 3BSC have been screened for its antimicrobial activity and found to exhibit antifungal and antibacterial effects. In addition, the Molecular docking was also performed for the different receptors.

Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV-Visible), NLO, NBO, HOMO-LUMO, Fukui function and molecular docking study of (E)-1-(5-bromo-2-hydroxybenzylidene)semicarbazide

NASA Astrophysics Data System (ADS)

Raja, M.; Raj Muhamed, R.; Muthu, S.; Suresh, M.

2017-08-01

The title compound, (E)-1-(5-bromo-2-hydroxybenzylidene)semicarbazide (15BHS) was synthesized and characterized by FT-IR, FT-Raman, UV, 1HNMR and 13CNMR spectral analysis. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and the Raman scattering activities were calculated by using density functional theory(DFT) B3LYP method with 6-311++G(d,p) basis set. The detailed interpretation of the vibrational spectra has been carried out by VEDA program. The calculated HOMO and LUMO energies show that charge transfer within the molecule. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). The first order hyperpolarizability, Molecular electrostatic potential (MEP) and Fukui functions were also performed. To study the biological activity of the investigation molecule, molecular docking was done to identify the hydrogen bond lengths and binding energy with different antifungal proteins. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the 15BHS at different temperatures have been calculated.

Fluorometric detection of nitroaromatics by fluorescent lead complexes: A spectroscopic assessment of detection mechanism

NASA Astrophysics Data System (ADS)

Chattopadhyay, Tanmay; Chatterjee, Sourav; Majumder, Ishani; Ghosh, Soumen; Yoon, Sangee; Sim, Eunji

2018-04-01

Three Schiff base ligands such as 2-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL1), 2-[(2-Hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL2), 2-[(3,5-Dichloro-2-hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL3) have been synthesized by condensation of aldehydes (such as 3,5-Dichloro-2-hydroxy benzaldehyde, 2-Hydroxy-benzaldehyde, and 2-Hydroxy-3-methoxy-benzaldehyde) with Tris-(hydroxymethyl)amino methane and characterized by IR, UV-vis and 1H NMR spectroscopy. Then all these three ligands have been used to prepare Pb(II) complexes by reaction with lead(II) acetate tri-hydrate in methanol. In view of analytical and spectral (IR, UV-vis and Mass) studies, it has been concluded that, except HL2, other two ligands form 1:1 metal complexes (1 and 3) with lead. Between two complexes, complex 3 is highly fluorescent and this property has been used to identify the pollutant nitroaromatics. Finally, the quenching mechanism has been established by means of spectroscopic investigation.

Quantum mechanical and spectroscopic (FT-IR, 13C, 1H NMR and UV) investigations of 2-(5-(4-Chlorophenyl)-3-(pyridin-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole by DFT method.

PubMed

Diwaker

2014-07-15

The electronic, NMR, vibrational, structural properties of a new pyrazoline derivative: 2-(5-(4-Chlorophenyl)-3-(pyridine-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole has been studied using Gaussian 09 software package. Using VEDA 4 program we have reported the PED potential energy distribution of normal mode of vibrations of the title compound. We have also reported the (1)H and (13)C NMR chemical shifts of the title compound using B3LYP level of theory with 6-311++G(2d,2p) basis set. Using time dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, electronic spectrum of the title compound has been studied and reported. NBO analysis and MEP surface mapping has also been calculated and reported using ab initio methods. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimicrobial Applications of Transition Metal Complexes of Benzothiazole Based Terpolymer: Synthesis, Characterization, and Effect on Bacterial and Fungal Strains

PubMed Central

Riswan Ahamed, Mohamed A.; Azarudeen, Raja S.; Kani, N. Mujafar

2014-01-01

Terpolymer of 2-amino-6-nitro-benzothiazole-ethylenediamine-formaldehyde (BEF) has been synthesized and characterized by elemental analysis and various spectral techniques like FTIR, UV-Visible, and 1H and 13C-NMR. The terpolymer metal complexes were prepared with Cu2+, Ni2+, and Zn2+ metal ions using BEF terpolymer as a ligand. The complexes have been characterized by elemental analysis and IR, UV-Visible, ESR, 1H-NMR, and 13C-NMR spectral studies. Gel permeation chromatography was used to determine the molecular weight of the ligand. The surface features and crystalline behavior of the ligand and its complexes were analyzed by scanning electron microscope and X-ray diffraction methods. Thermogravimetric analysis was used to analyze the thermal stability of the ligand and its metal complexes. Kinetic parameters such as activation energy (E a) and order of reaction (n) and thermodynamic parameters, namely, ΔS, ΔF, S*, and Z, were calculated using Freeman-Carroll (FC), Sharp-Wentworth (SW), and Phadnis-Deshpande (PD) methods. Thermal degradation model of the terpolymer and its metal complexes was also proposed using PD method. Biological activities of the ligand and its complexes were tested against Shigella sonnei, Escherichia coli, Klebsiella species, Staphylococcus aureus, Bacillus subtilis, and Salmonella typhimurium bacteria and Aspergillus flavus, Aspergillus niger, Penicillium species, Candida albicans, Cryptococcus neoformans, Mucor species fungi. PMID:25298760

Interaction of curcumin with Zn(II) and Cu(II) ions based on experiment and theoretical calculation

NASA Astrophysics Data System (ADS)

Zhao, Xue-Zhou; Jiang, Teng; Wang, Long; Yang, Hao; Zhang, Sui; Zhou, Ping

2010-12-01

Curcumin and its complexes with Zn 2+ and Cu 2+ ions were synthesized and characterized by elemental analysis, mass spectroscopy, IR spectroscopy, UV spectroscopy, solution 1H and solid-state 13C NMR spectroscopy, EPR spectroscopy. In addition, the density functional theory (DFT)-based UV and 13C chemical shift calculations were also performed to view insight into those compound structures and properties. The results show that curcumin easily chelate the metal ions, such as Zn 2+ and Cu 2+, and the Cu(II)-curcumin complex has an ability to scavenge free-radicals. We demonstrated the differences between Zn(II)-curcumin and Cu(II)-curcumin complexes in structure and properties, enhancing the comprehensions about the curcumin roles in the Alzhermer's disease treatment.

Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations.

PubMed

Karthikeyan, N; Joseph Prince, J; Ramalingam, S; Periandy, S

2015-05-15

In the present research work, the FT-IR, FT-Raman and (13)C and (1)H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, (13)C NMR and (1)H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

The new Schiff base 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one: Experimental, DFT calculational studies and in vitro antimicrobial activity

NASA Astrophysics Data System (ADS)

İskeleli, Nazan Ocak; Alpaslan, Yelda Bingöl; Direkel, Şahin; Ertürk, Aliye Gediz; Süleymanoğlu, Nevin; Ustabaş, Reşat

2015-03-01

The synthesized Schiff base, 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (I), has been characterized by 13C NMR, 1H NMR, 2D NMR (1H-1H COSY and 13C APT), FT-IR, UV-vis and X-ray single-crystal techniques. Molecular geometry of the compound I in the ground state, vibrational frequencies and chemical shift values have been calculated by using the density functional method (DFT) with 6-311++G(d,p) basis set. The obtained results indicate that optimized geometry can well reflect the crystal structural parameters. The differences between experimental and calculated results of FT-IR and NMR have supported the existence of intermolecular (O-H⋯O type) and intramolecular (C-H⋯O type) hydrogen bonds in the crystal structure. Molecular electrostatic potential (MEP), frontier molecular orbital analysis (HOMO-LUMO) and electronic absorption spectra were carried out at B3LYP/6-311G++(d,p). HOMO-LUMO electronic transition of 3.92 eV is due to contribution of the bands the n → π∗. The antimicrobial activity of the compound I was determined against the selected 11 bacteria and 8 fungi by microdilution broth assay with Alamar Blue. In vitro studies showed that the compound I has no antifungal effect for selected fungal isolates. However, the compound I shows remarkable antibacterial effect for the bacteria; Streptococcus pneumoniae, Haemophilus influenzae and Enterococcus faecalis.

FT-IR, FT-Raman, NMR and UV-Vis spectra and DFT calculations of 5-bromo-2-ethoxyphenylboronic acid (monomer and dimer structures)

NASA Astrophysics Data System (ADS)

Sas, E. B.; Kose, E.; Kurt, M.; Karabacak, M.

2015-02-01

In this study, the Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of 5-bromo-2-ethoxyphenylboronic acid (5Br2EPBA) are recorded in the solid phase in the region 4000-400 cm-1 and 3500-10 cm-1, respectively. The 1H, 13C and DEPT nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The UV-Vis absorption spectrum of 5Br2EPBA is saved in the range of 200-400 nm in ethanol and water. The following theoretical calculations for monomeric and dimeric structures are supported by experimental results. The molecular geometry and vibrational frequencies in the ground state are calculated by using DFT methods with 6-31G(d,p) and 6-311G(d,p) basis sets. There are four conformers for the present molecule. The computational results diagnose the most stable conformer of 5Br2EPBA as Trans-Cis (TC) form. The complete assignments are performed on the basis of the total energy distribution (TED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method in parallel quantum solutions (PQS) program. The 1H and 13C NMR chemical shifts of 5Br2EPBA molecule are calculated by using the Gauge Invariant Atomic Orbital (GIAO) method in DMSO and gas phase for monomer and dimer structures of the most stable conformer. Moreover, electronic properties, such as the HOMO and LUMO energies (by TD-DFT and CIS methods) and molecular electrostatic potential surface (MEPs) are investigated. Stability of the molecule arising from hyper-conjugative interactions, charge delocalization is analyzed using natural bond orbital (NBO) analysis. Nonlinear optical (NLO) properties and thermodynamic features are presented. All calculated results are compared with the experimental data of the title molecule. The correlation of theoretical and experimental results provides a detailed description of the structural and physicochemical properties of the title molecule.

Synthesis, crystal structure analysis, spectral (NMR, FT-IR, FT-Raman and UV-Vis) investigations, molecular docking studies, antimicrobial studies and quantum chemical calculations of a novel 4-chloro-8-methoxyquinoline-2(1H)-one: An effective antimicrobial agent and an inhibition of DNA gyrase and lanosterol-14α-demethylase enzymes

NASA Astrophysics Data System (ADS)

Murugavel, S.; Sundramoorthy, S.; Lakshmanan, D.; Subashini, R.; Pavan Kumar, P.

2017-03-01

The novel title compound 4-chloro-8-methoxyquinoline-2(1H)-one (4CMOQ) has been synthesized by slow evaporation solution growth technique at room temperature. The synthesized 4CMOQ molecule was characterized experimentally by FT-IR, FT-Raman, UV-Vis, NMR and single crystal diffraction (XRD) and theoretically by quantum chemical calculations. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311++G (d,p) basis set in ground state and compared with the experimental data. The entire vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED) by VEDA 4 programme. The nuclear magnetic resonance spectra (1H and 13C NMR) are obtained by using the gauge-invariant atomic orbital (GIAO) method. The change in electron density (ED) in the antibonding orbital's and stabilization energies E(2) of the molecule have been evaluated by natural bond orbital (NBO) analysis to give clear evidence of stabilization. Moreover, electronic characteristics such as HOMO and LUMO energies, Mulliken atomic charges and molecular electrostatic potential surface are investigated. Absorption spectrum analysis, nonlinear optical properties, chemical reactivity descriptors and thermodynamic features are also outlined theoretically. Molecular docking studies were executed to understand the inhibitory activity of 4CMOQ against DNA gyrase and Lanosterol 14 α-demethylase. The antimicrobial activity of 4CMOQ was determined against bacterial strains such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and fungal strains such as Aspergillus niger, Monascus purpureus and Penicillium citrinum. The obtained results show that the compound exhibited good to moderate antimicrobial activity.

FT-IR, FT-Raman, NMR and UV-Vis spectra and DFT calculations of 5-bromo-2-ethoxyphenylboronic acid (monomer and dimer structures).

PubMed

Sas, E B; Kose, E; Kurt, M; Karabacak, M

2015-02-25

In this study, the Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of 5-bromo-2-ethoxyphenylboronic acid (5Br2EPBA) are recorded in the solid phase in the region 4000-400 cm(-1) and 3500-10 cm(-1), respectively. The (1)H, (13)C and DEPT nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The UV-Vis absorption spectrum of 5Br2EPBA is saved in the range of 200-400 nm in ethanol and water. The following theoretical calculations for monomeric and dimeric structures are supported by experimental results. The molecular geometry and vibrational frequencies in the ground state are calculated by using DFT methods with 6-31G(d,p) and 6-311G(d,p) basis sets. There are four conformers for the present molecule. The computational results diagnose the most stable conformer of 5Br2EPBA as Trans-Cis (TC) form. The complete assignments are performed on the basis of the total energy distribution (TED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method in parallel quantum solutions (PQS) program. The (1)H and (13)C NMR chemical shifts of 5Br2EPBA molecule are calculated by using the Gauge Invariant Atomic Orbital (GIAO) method in DMSO and gas phase for monomer and dimer structures of the most stable conformer. Moreover, electronic properties, such as the HOMO and LUMO energies (by TD-DFT and CIS methods) and molecular electrostatic potential surface (MEPs) are investigated. Stability of the molecule arising from hyper-conjugative interactions, charge delocalization is analyzed using natural bond orbital (NBO) analysis. Nonlinear optical (NLO) properties and thermodynamic features are presented. All calculated results are compared with the experimental data of the title molecule. The correlation of theoretical and experimental results provides a detailed description of the structural and physicochemical properties of the title molecule. Copyright © 2014 Elsevier B.V. All rights reserved.

ACETYL CHOLINESTERASE AND BUTYRYL CHOLINESTERASE INhIBITORY ACTIVITIES OF ZALEYA PENTANDRA.

PubMed

Afzal, Samina; Chaudhry, Bashir Ahmad; Afzal, Khurram; Saeed, Javeria; Akash, Sajd Hamid; Qadir, Muhammad Imran

2017-05-01

The aim of this study was to reveal acetyl cholinesterase (AchE) and butyryl cholinesterase (BchE) inhibitory activities of Zaleya pentandra. The aerial parts of the plant were air, freeze-dried and powdered. The extraction was carried out with methanol at room temperature for 24 h. The extract was concentrated on rotavapor and fractioned by column chromatography. The isolation and purification afforded amorphous solid which was subjected to physical, chemical and spectroscopic techniques i.e., UV, IR, H-NMR, "C-NMR and HREI-MS for the structure elucidation of the isolated compound. The compound was concluded as "Pentandradione" a novel compound. AchE and BchE inhibitory activities were estimated. The result showed that the isolated extract possessed significant activity against butyryl cholinesterase as compared to standard eserine while the extract lacks acetyl cholinesterase inhibitory activity.

[Identity and physicochemical properties of 1-(4-chlorophenyl)-4-morpholino-imidazolin-2-one, AWD 131-138].

PubMed

Heinecke, K; Thiel, W

2001-06-01

The structure of the anticonvulsant 1-(4-chlorophenyl)-4-(4-morpholinyl)-2,5-dihydro-1H-imidazolin-2-one (Code: AWD 131-138, CAS-No.: 188116-07-6) was proved by IR, UV, 1H NMR, 13C NMR and mass spectra. AWD 131-138 is practically insoluble in a neutral aqueous medium at 20 degrees C (S approximately 0.08 g/l). The solubility of the substance in 0.1 N HCl is about 2.7 g/l. In DMF, AWD 131-138 is sparingly soluble (S approximately 28.5 g/l). The pKa-value is about 2.5. The partition coefficients P = COctanol/Cwater at 37 degrees C range from 0.7 at pH approximately 1 to about 20 at pH > or = 6.

Nonlinear optical studies and structure-activity relationship of chalcone derivatives with in silico insights

NASA Astrophysics Data System (ADS)

Kar, Swayamsiddha; Adithya, K. S.; Shankar, Pruthvik; Jagadeesh Babu, N.; Srivastava, Sailesh; Nageswara Rao, G.

2017-07-01

Nine chalcones were prepared via Claisen-Schmidt condensation, and characterized by UV-vis, IR, 1H NMR, 13C NMR and mass spectrometry. One of the representative member 4-NDM-TC has been studied via single crystal XRD and the TGA/DTA technique. SHG efficiency and NLO susceptibilities of the chalcones have been evaluated by the Kurtz and Perry method and Degenerate Four Wave Mixing techniques respectively. 3-Cl-4‧-HC was noted to possess SHG efficiency 1.37 times that of urea while 4-NDM-TC returned the highest third order NLO susceptibilities with respect to CS2. In silico studies help evaluate various physical parameters, in correlating the observed activities. In conclusion, the structure-activity relationship was derived based on the in silico and experimental results for the third order NLO susceptibilities.

In silico modeling and synthesis of phenyl and thienyl analogs of chalcones for potential leads as anti-bacterial agents

NASA Astrophysics Data System (ADS)

Kar, Swayamsiddha; Mishra, Rohit Kumar; Pathak, Ashutosh; Dikshit, Anupam; Golakoti, Nageswara Rao

2018-03-01

In the recent times, the common diseases like food poisoning, pneumonia, diarrhea etc. have been observed to be drug resistant. The present study deals with the synthesis of known chalcone derivatives using the Claisen-Schmidt condensation and further characterization using UV-vis, IR, 1H NMR, 13C NMR and mass spectrometry. These derivatives were first simulated for their anti-bacterial efficacy in silico and consequently confirmed in vitro to confirm the findings. One of the chalcones, 4-NDM-2‧-HC showed excellent in-vitro antibacterial activity with an IC90 0.43 mg/mL against Vibrio cholerae as compared to commercially available antibiotic gentamicin as the standard. Further, all these tested chalcone derivatives fulfill Lipinski's parameters and show tremendous drug likeness score, confirming their potential as antibacterial leads.

Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

PubMed Central

2012-01-01

Background A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results The structure of the dyes was confirmed by UV-vis, FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusions The azo-hydrazone tautomeric equilibration was found to depend on the substituents as well as on the solvent. The geometry data of the investigated dyes were obtained using DFT quantum-chemical calculations. The obtained calculational results are in very good agreement with the experimental data. PMID:22824496

Microwave Assisted Synthesis, Physicochemical, Photophysical, Single Crystal X-ray and DFT Studies of Novel Push-Pull Chromophores.

PubMed

Khan, Salman A; Asiri, Abdullah M; Basisi, Hadi Mussa; Arshad, Muhammad Nadeem; Sharma, Kamlesh

2015-11-01

Two push-pull chromophores were synthesized by knoevenagel condensation under microwave irradiation. The structure of synthesized chromophores were established by spectroscopic (FT-IR, (1)H NMR, (13)C NMR, EI-MS) and elemental analysis. Structure of the chromophores was further conformed by X-ray crystallographic. UV-Vis and fluorescence spectroscopy measurements provided that chromophores were good absorbent and fluorescent properties. Fluorescence polarity studies demonstrated that chromophores were sensitive to the polarity of the microenvironment provided by different solvents. Physicochemical parameters, including singlet absorption, extinction coefficient, stokes shift, oscillator strength, dipole moment and flurescence quantum yield were investigated in order to explore the analytical potential of the synthesized chromophores. In addition, the total energy, frontier molecular orbitals, hardness, electron affinity, ionization energy, electrostatic potential map were also studied computationally by using density functional theoretical method.

Electronic [UV-Visible] and vibrational [FT-IR, FT-Raman] investigation and NMR-mass spectroscopic analysis of terephthalic acid using quantum Gaussian calculations.

PubMed

Karthikeyan, N; Prince, J Joseph; Ramalingam, S; Periandy, S

2015-03-15

In this research work, the vibrational IR, polarization Raman, NMR and mass spectra of terephthalic acid (TA) were recorded. The observed fundamental peaks (IR, Raman) were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The molecular mass spectral data related to base molecule and substitutional group of the compound was analyzed. The modification of the chemical property by the reaction mechanism of the injection of dicarboxylic group in the base molecule was investigated. The (13)C and (1)H NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method and the absolute chemical shifts related to TMS were compared with experimental spectra. The study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by hybrid Gaussian calculation methods. The orbital energies of different levels of HOMO and LUMO were calculated and the molecular orbital lobe overlapping showed the inter charge transformation between the base molecule and ligand group. From the frontier molecular orbitals (FMO), the possibility of electrophilic and nucleophilic hit also analyzed. The NLO activity of the title compound related to Polarizability and hyperpolarizability were also discussed. The present molecule was fragmented with respect to atomic mass and the mass variation depends on the substitutions have also been studied. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Molecular structure investigation of neutral, dimer and anion forms of 3,4-pyridinedicarboxylic acid: A combined experimental and theoretical study

NASA Astrophysics Data System (ADS)

Karabacak, Mehmet; Bilgili, Sibel; Atac, Ahmet

2015-01-01

In this study, the structural and vibrational analysis of 3,4-pyridinedicarboxylic acid (3,4-PDCA) are presented using experimental techniques as FT-IR, FT-Raman, NMR, UV and quantum chemical calculations. FT-IR and FT-Raman spectra of 3,4-pyridinedicarboxylic acid in the solid phase are recorded in the region 4000-400 cm-1 and 4000-50 cm-1, respectively. The geometrical parameters and energies of all different and possible monomer, dimer, anion-1 and anion-2 conformers of 3,4-PDCA are obtained from Density Functional Theory (DFT) with B3LYP/6-311++G(d,p) basis set. There are sixteen conformers (C1sbnd C16) for this molecule (neutral form). The most stable conformer of 3,4-PDCA is the C1 conformer. The complete assignments are performed on the basis of the total energy distribution (TED) of the vibrational modes calculated with scaled quantum mechanics (SQM) method. 1H and 13C NMR spectra are recorded and the chemical shifts are calculated by using DFT/B3LYP methods with 6-311++G(d,p) basis set. The UV absorption spectrum of the studied compound is recorded in the range of 200-400 nm by dissolved in ethanol. The optimized geometric parameters were compared with experimental data via the X-ray results derived from complexes of this molecule. In addition these, molecular electrostatic potential (MEP), thermodynamic and electronic properties, HOMO-LUMO energies and Mulliken atomic charges, are performed.

Synthesis, spectroscopic (FT-IR, FT-Raman, UV and NMR) and computational studies on 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone

NASA Astrophysics Data System (ADS)

Arockia doss, M.; Savithiri, S.; Rajarajan, G.; Thanikachalam, V.; Saleem, H.

2015-09-01

The structural and spectroscopic studies of 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone (PDPOSC) were made by adopting B3LYP/HF levels theory using 6-311++G(d,p) basis set. The FT-IR and Raman spectra were recorded in solid phase, the fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. DFT method indicates that B3LYP is superior to HF method for molecular vibrational analysis. UV-vis spectrum of the compound was recorded in different solvents in the region of 200-800 nm and the electronic properties such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies were evaluated by time-dependent DFT (TD-DFT) approach. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. The hyperconjugative interaction energy (E(2)) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. In addition, MEP and atomic charges of carbon, nitrogen and oxygen were calculated using B3LYP/6-311++G(d,p) level theory. Moreover, thermodynamic properties of the title compound were calculated by B3LYP/HF, levels using 6-311++G(d,p) basis set. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.

Synthesis, spectroscopic, single crystal diffraction and potential nonlinear optical properties of novel pyrazoline derivatives: Interplay of experimental and computational analyses.

PubMed

Arshad, Muhammad Nadeem; Birinji, Abdulhadi Salih; Khalid, Muhammad; Asiri, Abdullah M; Al-Amry, Khalid A; Aqlan, Faisal M S; Braga, Ataualpa A C

2018-09-05

Pyrazoline are widely being studied due to their potential applications in chemical field. Herein, five pyrazolines compounds were synthesized and characterized spectroscopically using nuclear magnetic resonance techniques ( 1 H NMR & 13 C NMR) to determine the structures of molecules along-with UV-Visible and infrared (FT-IR) studies for additional spectroscopic support in characterization of entitle synthesized molecules. Unit cells, specific space groups, bond lengths, bond angles and hydrogen bonding interactions were determined by the x-ray diffraction studies. Further, computational study of compounds with B3LYP/6-311 + G(d,p) level were carried out to explore optimized geometry, spectroscopic data for FT-IR, frontier molecular orbitals (FMOs) and non-linear optical (NLO) parameters. While, UV-Vis spectral were performed by TD-DFT/B3LYP/6-311 + G(d,p) level. The experimental results of spectroscopic and single crystal studies were compared and found in good agreement with the computational. The global reactivity parameters have been calculated with the help of the energy of FMOs. The order for the total first and second order hyperpolarizabilities of 1-5 is found in the following orders: 1 > 4 > 3 > 5 > 2 and 1 > 4 > 5 > 2 > 3 respectively. Overall, greater NLO response than urea molecule prove that investigated molecules are excellent candidate for NLO applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular structure investigation of neutral, dimer and anion forms of 3,4-pyridinedicarboxylic acid: a combined experimental and theoretical study.

PubMed

Karabacak, Mehmet; Bilgili, Sibel; Atac, Ahmet

2015-01-25

In this study, the structural and vibrational analysis of 3,4-pyridinedicarboxylic acid (3,4-PDCA) are presented using experimental techniques as FT-IR, FT-Raman, NMR, UV and quantum chemical calculations. FT-IR and FT-Raman spectra of 3,4-pyridinedicarboxylic acid in the solid phase are recorded in the region 4000-400 cm(-1) and 4000-50 cm(-1), respectively. The geometrical parameters and energies of all different and possible monomer, dimer, anion(-1) and anion(-2) conformers of 3,4-PDCA are obtained from Density Functional Theory (DFT) with B3LYP/6-311++G(d,p) basis set. There are sixteen conformers (C1C16) for this molecule (neutral form). The most stable conformer of 3,4-PDCA is the C1 conformer. The complete assignments are performed on the basis of the total energy distribution (TED) of the vibrational modes calculated with scaled quantum mechanics (SQM) method. (1)H and (13)C NMR spectra are recorded and the chemical shifts are calculated by using DFT/B3LYP methods with 6-311++G(d,p) basis set. The UV absorption spectrum of the studied compound is recorded in the range of 200-400 nm by dissolved in ethanol. The optimized geometric parameters were compared with experimental data via the X-ray results derived from complexes of this molecule. In addition these, molecular electrostatic potential (MEP), thermodynamic and electronic properties, HOMO-LUMO energies and Mulliken atomic charges, are performed. Copyright © 2014 Elsevier B.V. All rights reserved.

Curcumin-Zn(II) complex for enhanced solubility and stability: an approach for improved delivery and pharmacodynamic effects.

PubMed

Sareen, Rashmi; Jain, Nitin; Dhar, K L

2016-08-01

The aim of present investigation was to prepare Curcumin-Zn(II) complex in a view to enhance solubility, stability and pharmacodynamic effect in experimentally induced ulcerative colitis. Curcumin-Zn(II) complex was prepared by stirring curcumin with anhydrous zinc chloride at a molar ratio of 1:1. The prepared curcumin metallocomplex was characterized by TLC, FTIR, UV spectroscopy and (1)H NMR. In vitro kinetic degradation and solubility of Curcumin and Curcumin-Zn(II) complex was analyzed spectrophotometrically. Pharmacodynamic evaluation of curcumin and its metal complex was assessed in ulcerative colitis in mice. Curcumin showed chelation with zinc ion as confirmed by the TLC, FTIR, UV spectroscopy and (1)H NMR. The results of TLC [Rf value], IR Spectroscopy [shifting of stretching vibrations of υ(C=C) and υ(C=O)], UV spectra [deconvoluted with absorption band at 432-466.4 nm] of Curcumin-Zn(II) complex compared to curcumin confirmed the formation of metallocomplex. (1)HNMR spectra of Curcumin-Zn(II) showed the upfield shift of Ha and Hb. Kinetic stability studies showed metallocomplex with zinc exhibited good stability. In vivo study revealed significant reduction in severity and extent of colonic damage with Curcumin-Zn(II) which were further confirmed by histopathological study. This study recognizes higher solubility and stability of Curcumin-Zn(II) complex and suggested better pharmacodynamic effects.

Phosphorescent binuclear iridium complexes based on terpyridine-carboxylate: an experimental and theoretical study.

PubMed

Andreiadis, Eugen S; Imbert, Daniel; Pécaut, Jacques; Calborean, Adrian; Ciofini, Ilaria; Adamo, Carlo; Demadrille, Renaud; Mazzanti, Marinella

2011-09-05

The phosphorescent binuclear iridium(III) complexes tetrakis(2-phenylpyridine)μ-(2,2':6',2''-terpyridine-6,6''-dicarboxylic acid)diiridium (Ir1) and tetrakis(2-(2,4-difluorophenyl) pyridine))μ-(2,2':6',2''-terpyridine-6,6''-dicarboxylic acid)diiridium (Ir2) were synthesized in a straightforward manner and characterized using X-ray diffraction, NMR, UV-vis absorption, and emission spectroscopy. The complexes have similar solution structures in which the two iridium centers are equivalent. This is further confirmed by the solid state structure of Ir2. The newly reported complexes display intense luminescence in dichloromethane solutions with maxima at 538 (Ir1) and 477 nm (Ir2) at 298 K (496 and 468 nm at 77 K, respectively) and emission quantum yields reaching ~18% for Ir1. The emission quantum yield for Ir1 is among the highest values reported for dinuclear iridium complexes. It shows only a 11% decrease with respect to the emission quantum yield reported for its mononuclear analogue, while the molar extinction coefficient is roughly doubled. This suggests that such architectures are of potential interest for the development of polymetallic assemblies showing improved optical properties. DFT and time-dependent-DFT calculations were performed on the ground and excited states of the complexes to provide insights into their structural, electronic, and photophysical properties.

Fire Protection System for Hardened Aircraft Shelters. Volume 1. Discussion and Appendixes A-C

DTIC Science & Technology

1987-10-01

in any configuration, for exanple IR, lR-lR, UV -IR, UV , UV -IR- UV . The advantage of multiwavelength detectors is a reduced likelihood of false alarm. B...11late is ,ai led the work function if the metal. Th, operating envelope of a UV detector is . function u (i) the Inc-tal used fir the cathode, and Ŗ...second or two longer. E. DI1AL-CHANNEL UV /IR JETIT .OIRS iiarmy false alar.m sources for UV and IR detectors are mutally exclusive. Th -. has led to the

Isolation and structural characterization of a novel sibutramine analogue, chlorosipentramine, in a slimming dietary supplement, by using HPLC-PDA, LC-Q-TOF/MS, FT-IR, and NMR.

PubMed

Yun, Jisuk; Shin, Kye Jung; Choi, Jangduck; Jo, Cheon-Ho

2018-05-01

A novel sibutramine analogue was detected in a slimming formula by high performance liquid chromatography with a photo diode detector array (HPLC-PDA). The unknown compound exhibited an ultraviolet (UV) spectrum that was similar to that of chlorosibutramine, despite having a different HPLC retention time. Further analysis of the slimming formula by LC-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) showed that the unknown compound had the formula C 18 H 27 Cl 2 N. To elucidate the structure of this new sibutramine analogue, the target compound in the slimming formula was isolated on a preparative-LC system equipped with a PDA. After analysis by fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy, the unknown compound was identified as a sibutramine analogue in which the iso-butyl group on the side chain is replaced with an iso-pentyl group. This new sibutramine analogue was identified to be 1-(1-(3,4-dichlorophenyl)cyclobutyl)-N,N,4-trimethylpentan-1-amine and has been named as chlorosipentramine. Copyright © 2018 Elsevier B.V. All rights reserved.

Novel water soluble morpholine substituted Zn(II) phthalocyanine: Synthesis, characterization, DNA/BSA binding, DNA photocleavage and topoisomerase I inhibition.

PubMed

Barut, Burak; Demirbaş, Ümit; Özel, Arzu; Kantekin, Halit

2017-12-01

In this study, novel peripherally tetra 3-morpholinophenol substituted zinc(II) phthalocyanine (4) and its water soluble form quaternized zinc(II) phthalocyanine (ZnQ) were synthesized for the first time. These novel compounds were characterized by a combination of different spectroscopic techniques such as FT-IR, 1 H NMR, 13 C NMR, UV-vis and mass. The DNA binding of ZnQ was investigated using UV-vis absorption titration, competitive ethidium bromide, thermal denaturation and viscosity experiments that the ZnQ bound to CT-DNA via intercalation mode. ZnQ indicated photocleavage activity on supercoiled pBR322 plasmid DNA via formation of singlet oxygen under irradiation at 700nm. Besides, the topoisomerase I inhibitory effect experiments showed that ZnQ inhibited topoisomerase I enzyme in a concentration-dependent manner. The bovine serum albumin (BSA) binding experiments indicated that ZnQ bound to proteins through a static quenching mechanism. All of these results claim that ZnQ has potential agent for photodynamic therapy owing to its nucleic acid interactions and photobiological or photochemical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural investigation of a self-assembled monolayer material 5-[(3-methylphenyl) (phenyl) amino] isophthalic acid for organic light-emitting devices.

PubMed

Saş, E Babur; Kurt, M; Can, M; Okur, S; İçli, S; Demiç, S

2014-12-10

The molecular structure and vibrations of 5-[(3-methylphenyl) (phenyl) amino] isophthalic acid (MePIFA) were investigated by infrared and Raman spectroscopies, UV-Vis, (1)H and (13)C NMR spectroscopic techniques and NBO analysis. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. (1)H and (13)C NMR spectra and UV-Vis spectrum were recorded in DMSO solution. HOMO-LUMO analysis and molecular electrostatic potential (MEP) analysis were performed. The theoretical calculations for the molecular structure and spectroscopies were performed with DFT (B3LYP) and 6-311G(d,p) basis set calculations using the Gaussian 09 program. After the geometry of the molecule was optimized, vibration wavenumbers and fundamental vibration wavenumbers were assigned on the basis of the potential energy distribution (PED) of the vibrational modes calculated with VEDA 4 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analysis were made using GaussSum 2.2 program. The results of theoretical calculations for the spectra of the title compound were compared with the observed spectra. Copyright © 2014 Elsevier B.V. All rights reserved.

Structural investigation of a self-assembled monolayer material 5-[(3-methylphenyl) (phenyl) amino] isophthalic acid for organic light-emitting devices

NASA Astrophysics Data System (ADS)

Saş, E. Babur; Kurt, M.; Can, M.; Okur, S.; İçli, S.; Demiç, S.

2014-12-01

The molecular structure and vibrations of 5-[(3-methylphenyl) (phenyl) amino] isophthalic acid (MePIFA) were investigated by infrared and Raman spectroscopies, UV-Vis, 1H and 13C NMR spectroscopic techniques and NBO analysis. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H and 13C NMR spectra and UV-Vis spectrum were recorded in DMSO solution. HOMO-LUMO analysis and molecular electrostatic potential (MEP) analysis were performed. The theoretical calculations for the molecular structure and spectroscopies were performed with DFT (B3LYP) and 6-311G(d,p) basis set calculations using the Gaussian 09 program. After the geometry of the molecule was optimized, vibration wavenumbers and fundamental vibration wavenumbers were assigned on the basis of the potential energy distribution (PED) of the vibrational modes calculated with VEDA 4 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analysis were made using GaussSum 2.2 program. The results of theoretical calculations for the spectra of the title compound were compared with the observed spectra.

DNA Binding, Cleavage and Antibacterial Activity of Mononuclear Cu(II), Ni(II) and Co(II) Complexes Derived from Novel Benzothiazole Schiff Bases.

PubMed

Vamsikrishna, Narendrula; Kumar, Marri Pradeep; Tejaswi, Somapangu; Rambabu, Aveli; Shivaraj

2016-07-01

A series of novel bivalent metal complexes M(L1)2 and M(L2)2 where M = Cu(II), Ni(II), Co(II) and L1 = 2-((benzo [d] thiazol-6-ylimino)methyl)-4-bromophenol [BTEMBP], L2 = 1-((benzo [d] thiazol-6-ylimino)methyl) naphthalen-2-ol [BTEMNAPP] were synthesized. All the compounds have been characterized by elemental analysis, SEM, Mass, (1)H NMR, (13)C NMR, UV-Vis, IR, ESR, spectral data and magnetic susceptibility measurements. Based on the analytical and spectral data four-coordinated square planar geometry is assigned to all the complexes. DNA binding properties of these complexes have been investigated by electronic absorption spectroscopy, fluorescence and viscosity measurements. It is observed that these binary complexes strongly bind to calf thymus DNA by an intercalation mode. DNA cleavage efficacy of these complexes was tested in presence of H2O2 and UV light by gel electrophoresis and found that all the complexes showed better nuclease activity. Finally the compounds were screened for antibacterial activity against few pathogens and found that the complexes have potent biocidal activity than their free ligands.

Vibrational, NMR and UV-visible spectroscopic investigation and NLO studies on benzaldehyde thiosemicarbazone using computational calculations

NASA Astrophysics Data System (ADS)

Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Pandian, G. V.; Anbusrinivasan, P.

2016-04-01

In order to investigate the vibrational, electronic and NLO characteristics of the compound; benzaldehyde thiosemicarbazone (BTSC), the XRD, FT-IR, FT-Raman, NMR and UV-visible spectra were recorded and were analysed with the calculated spectra by using HF and B3LYP methods with 6-311++G(d,p) basis set. The XRD results revealed that the stabilized molecular systems were confined in orthorhombic unit cell system. The cause for the change of chemical and physical properties behind the compound has been discussed makes use of Mulliken charge levels and NBO in detail. The shift of molecular vibrational pattern by the fusing of ligand; thiosemicarbazone group with benzaldehyde has been keenly observed. The occurrence of in phase and out of phase molecular interaction over the frontier molecular orbitals was determined to evaluate the degeneracy of the electronic energy levels. The thermodynamical studies of the temperature region 100-1000 K to detect the thermal stabilization of the crystal phase of the compound were investigated. The NLO properties were evaluated by the determination of the polarizability and hyperpolarizability of the compound in crystal phase. The physical stabilization of the geometry of the compound has been explained by geometry deformation analysis.

DNA damage and repair in plants under ultraviolet and ionizing radiations.

PubMed

Gill, Sarvajeet S; Anjum, Naser A; Gill, Ritu; Jha, Manoranjan; Tuteja, Narendra

2015-01-01

Being sessile, plants are continuously exposed to DNA-damaging agents present in the environment such as ultraviolet (UV) and ionizing radiations (IR). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315-400 nm; UV-B, 280-315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damage. On the other hand, IR causes water radiolysis, which generates highly reactive hydroxyl radicals (OH(•)) and causes radiogenic damage to important cellular components. However, to maintain genomic integrity under UV/IR exposure, plants make use of several DNA repair mechanisms. In the light of recent breakthrough, the current minireview (a) introduces UV/IR and overviews UV/IR-mediated DNA damage products and (b) critically discusses the biochemistry and genetics of major pathways responsible for the repair of UV/IR-accrued DNA damage. The outcome of the discussion may be helpful in devising future research in the current context.

Synthesis, thermogravimetric, spectroscopic and theoretical characterization of copper(II) complex with 4-chloro-2-nitrobenzenosulfonamide

NASA Astrophysics Data System (ADS)

Camí, G.; Chacón Villalba, E.; Di Santi, Y.; Colinas, P.; Estiu, G.; Soria, D. B.

2011-05-01

4-Chloro-2-nitrobenzenesulfonamide (ClNbsa) was purified and characterized. A new copper(II) complex, [Cu(ClNbsa) 2(NH 3) 2], has been prepared using the sulfonamide as ligand. The thermal behavior of both, the ligand and the Cu(II) complex, was investigated by thermogravimetric analyses (TG) and differential thermal analysis (DT), and the electronic characteristics analyzed by UV-VIS, FTIR, Raman and 1H NMR spectroscopies. The experimental IR, Raman and UV-VIS spectra have been assigned on the basis of DFT calculations at the B3LYP level of theory using the standard (6-31 + G ∗∗) basis set. The geometries have been fully optimized in vacuum and in modeled dimethylsulfoxide (DMSO) solvent, using for the latter a continuum solvation model that reproduced the experimental conditions of the UV-VIS spectroscopy. The theoretical results converged to stable conformations for the free sulfonamide and for the complex, suggesting for the latter a distorted square planar geometry in both environments.

Ligubenzocycloheptanone A, a Novel Tricyclic Butenolide with a 6/7/5 Skeleton from Ligusticum chuanxiong

PubMed Central

Han, Bing; Zhang, Xu; Feng, Zi-Ming; Jiang, Jian-Shuang; Li, Li; Yang, Ya-Nan; Zhang, Pei-Cheng

2016-01-01

Ligubenzocycloheptanone A (1), a novel tricyclic butenolide with a 6/7/5-membered ring skeleton, was isolated from the rhizome of Ligusticum chuanxiong. Its unusual structure was determined using UV, IR, HRESIMS, 1D and 2D NMR data, X-ray diffraction crystallography and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. 1 possessed a benzocycloheptanone core featuring butyrolactone, which is rarely observed in nature. A possible biosynthetic pathway was proposed. Ligubenzocycloheptanone A showed strong radical scavenging activity with an IC50 value of 2.3 μM. PMID:27461841

Synthesis and study of conjugated polymers containing Di- or Triphenylamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sukwattanasinitt, M.

1996-06-21

This thesis consists of two separate parts. The first part addresses the synthesis and study of conjugated polymers containing di- or triphenylamine. Two types of polymers: linear polymers and dendrimers, were synthesized. The polymers were characterized by NMR, IR, UV, GPC, TGA and DSC. Electronic and optical properties of the polymers were studied through the conductivity measurements and excitation- emission spectra. the second part of this thesis deals with a reaction of electron-rich acetylenes with TCNE. The discovery of the reaction from charge transfer complex studies and the investigation of this reaction on various electron-rich acetylenes are presented.

New tetradentate Schiff bases of 2-amino-3,5-dibromobenzaldehyde with aliphatic diamines and their metal complexes: synthesis, characterization and thermal stability.

PubMed

Mohammadi, Khosro; Azad, Seyyedeh Sedigheh; Amoozegar, Ameneh

2015-07-05

The tetradentate Schiff base ligands (L(1)-L(4)), were synthesized by reaction between 2-amino-3,5-dibromobenzaldehyde and aliphatic diamines. Then, nickel and oxovanadium(IV) complexes of these ligands were synthesized and characterized by (1)H NMR, Mass, IR, UV-Vis spectroscopy and thermogravimetry. The kinetic parameters of oxovanadium(IV) complexes were calculated from thermal studies. According to the results of thermogravimetric data, the thermal stability of oxovanadium(IV) complexes is as follow: [Formula: see text]. Copyright © 2015 Elsevier B.V. All rights reserved.

Chalcones and other constituents of Dorstenia prorepens and Dorstenia zenkeri.

PubMed

Abegaz, Berhanu M; Ngadjui, Bonaventure T; Dongo, Etienne; Ngameni, Bathelemy; Nindi, Mathew N; Bezabih, Merhatibeb

2002-04-01

The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,3'-(3,7-dimethyl-2,6-octadienyl)-3,4, 2',4'-tetrahydroxychalcone while Dorstenia zenkeri yielded the 3',4'-(3-hydroxy-2,2-dimethyldihydropyrano)-4,2'-dihydroxychalcone and a bichalcone. 4-Hydroxylonchocarpin was found in both plants. D. prorepens also yielded the known compounds: psoralen, bergapten, beta-sitosterol and its D-glucopyranosyl derivative. D. zenkeri yielded p-hydroxybenzaldehyde, dorsmanin A, 4,2',4'-trihydroxychalcone and 4,2',4'-trihydroxy-3'-prenylchalcone. Structures of the new compounds were established by UV, IR, MS and 2-D NMR analysis.

Enteridinines A and B from slime mold Enteridium lycoperdon.

PubMed

Rezanka, Tomás; Dvoráková, Radmila; Hanus, Lumír O; Dembitsky, Valery M

2004-02-01

Two novel deoxysugar esters, named enteridinines A and B, were isolated from the slime mold Enteridium lycoperdon. Their structures, including the absolute configurations of the hydroxyl and methyl groups, were determined by means of extensive spectroscopic data such as UV, IR, MS, 1D and 2D NMR spectra. Enteridinines A and B have unique structures containing 1,7-dioxaspiro[5.5]undecanes with an O-beta-D-mycarosyl-(1-->4)-beta-D-olivosyl and an O-beta-L-olivomycosyl-(1-->4)-beta-D-amicetosyl-(1-->4)-beta-L-digitoxosyl unit, respectively, and showed growth inhibitory activities against Gram positive bacteria.

Synthesis, structural elucidation and pharmacological properties of some 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H) -pyrimidinones.

PubMed

Yarim, M; Sarac, S; Ertan, M; Batu, O S; Erol, K

1999-06-30

In this study, the synthesis of some new 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H)-pyrimidinones has been reported. The compounds were prepared by the Biginelli reaction of acetylacetone with aromatic aldehydes and urea. The structures of the compounds were characterized by UV, IR, 1H NMR, 13C NRM, mass spectra and elementary analysis. The calcium antagonistic activity of these compounds was tested in vitro on rat ileum precontracted with 4 x 10(-3) M barium chloride.

[Chemical constituents from the rhizoma of Arundina graminifolia].

PubMed

Liu, Mei-feng; Han, Yun; Xing, Dong-ming; Wang, Wei; Xu, Li-zhen; Du, Li-jun; Ding, Yi

2004-02-01

To isolate and elucidate the chemical constituents from the tuber of Arundina graminifolia. The compounds were extracted by 95% alcohol and isolated by column chromatography on silica gel, SephedaxLH-20 and ODS. The structures were determined by UV, IR, NMR and MS spectral analysis. Five compounds were isolated, and their structures were identified as (2E)-, 2-propenoic acid, 3-(4-hydroxy-3-methoxyphenyl)-decosyl ester (I), p-hydroxybenzyl alcohol (II), triacontanol (III) and p-hydroxybenzylethyl ether (IV), 3-hydroxy-5-methoxybibenzyl (V), respectively. All compounds were isolated from the genus of Arundina for the first time.

Valsartan.

PubMed

Ardiana, Febry; Suciati; Indrayanto, Gunawan

2015-01-01

Valsartan is an antihypertensive drug which selectively inhibits angiotensin receptor type II. Generally, valsartan is available as film-coated tablets. This review summarizes thermal analysis, spectroscopy characteristics (UV, IR, MS, and NMR), polymorphism forms, impurities, and related compounds of valsartan. The methods of analysis of valsartan in pharmaceutical dosage forms and in biological fluids using spectrophotometer, CE, TLC, and HPLC methods are discussed in details. Both official and nonofficial methods are described. It is recommended to use LC-MS method for analyzing valsartan in complex matrices such as biological fluids and herbal preparations; in this case, MRM is preferred than SIM method. © 2015 Elsevier Inc. All rights reserved.

Flavonoids from the roots of Artocarpus heterophyllus.

PubMed

Yuan, Wen-Jun; Yuan, Jin-Bin; Peng, Jia-Bing; Ding, Yuan-Qing; Zhu, Ji-Xiao; Ren, Gang

2017-03-01

Four new flavonoids, artoheteroids A-D (1-4), together with six known ones (5-10), were isolated from the roots of Artocarpus heterophyllus. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR, UV, IR, CD, and HR-ESI-MS. All isolated compounds were screened for their inhibitory abilities against cathepsin K (CatK). Among them, compounds 1-2, 4-6, and 10 were found to have suppression capabilities against CatK with IC 50 values ranging from 1.4 to 93.9μM. Copyright © 2017 Elsevier B.V. All rights reserved.

New Gel-Like Polymers as Selective Weak-Base Anion Exchangers

PubMed Central

Gierczyk, Błażej; Cegłowski, Michał; Zalas, Maciej

2015-01-01

A group of new anion exchangers, based on polyamine podands and of excellent ion-binding capacity, were synthesized. The materials were obtained in reactions between various poly(ethyleneamines) with glycidyl derivatives of cyclotetrasiloxane. The final polymeric, strongly cross-linked materials form gel-like solids. Their structures and interactions with anions adsorbed were studied by spectroscopic methods (CP-MAS NMR, FR-IR, UV-Vis). The sorption isotherms and kinetic parameters were determined for 29 anions. Materials studied show high ion capacity and selectivity towards some important anions, e.g., selenate(VI) or perrhenate. PMID:25946220

Verticillosides A-M: Polyoxygenated pregnane glycosides from Asclepias verticillata L.

PubMed

Araya, Juan J; Binns, Franklin; Kindscher, Kelly; Timmermann, Barbara N

2012-06-01

As part of our ongoing effort to explore the chemical diversity of plants of the United States Midwest region, the isolation and identification of 13 pregnane glycosides named verticillosides A-M from Asclepias verticillata L. are reported. The structures of these compounds were elucidated by various spectroscopic techniques, including 1D and 2D NMR, IR, UV, and HRMS. The cytotoxicity of the isolates was evaluated against paired breast cell lines Hs578T (cancer) and Hs578Bst (normal), however, no significant growth inhibition was observed. Copyright © 2012 Elsevier Ltd. All rights reserved.

DNA Damage and Repair in Plants under Ultraviolet and Ionizing Radiations

PubMed Central

Gill, Sarvajeet S.; Gill, Ritu; Jha, Manoranjan; Tuteja, Narendra

2015-01-01

Being sessile, plants are continuously exposed to DNA-damaging agents present in the environment such as ultraviolet (UV) and ionizing radiations (IR). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315–400 nm; UV-B, 280–315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damage. On the other hand, IR causes water radiolysis, which generates highly reactive hydroxyl radicals (OH•) and causes radiogenic damage to important cellular components. However, to maintain genomic integrity under UV/IR exposure, plants make use of several DNA repair mechanisms. In the light of recent breakthrough, the current minireview (a) introduces UV/IR and overviews UV/IR-mediated DNA damage products and (b) critically discusses the biochemistry and genetics of major pathways responsible for the repair of UV/IR-accrued DNA damage. The outcome of the discussion may be helpful in devising future research in the current context. PMID:25729769

Synthesis, spectroscopy and computational studies of some biologically important hydroxyhaloquinolines and their novel derivatives

NASA Astrophysics Data System (ADS)

Malecki, Grzegorz; Nycz, Jacek E.; Ryrych, Ewa; Ponikiewski, Lukasz; Nowak, Maria; Kusz, Joachim; Pikies, Jerzy

2010-04-01

A series crystalline compounds of methyl and phosphinyl derivatives of 2-methylquinolin-8-ol ( 1a) and related 5,7-dichloro-2-methylquinolin-8-ol ( 1b) were quantitatively prepared and characterized by microanalysis, IR, UV-vis and multinuclear NMR spectroscopy. Five of them have been characterized by single crystal X-ray diffraction method. The known compounds, 8-methoxy-2-methylquinoline ( 2a) and 8-methoxyquinoline ( 2d), were synthesised by a new route. NMR solution spectra at ambient temperature, showed readily diagnostic H-1 and C-13 signals from methyl groups. The geometries of the studied compounds were optimized in singlet states using the density functional theory (DFT) method with B3LYP functional. In general, the predicted bond lengths and angles are in a good agreement with the values based on the X-ray crystal structure data. Electronic spectra were calculated by TDDFT method.

Coordination Polymer: Synthesis, Spectral Characterization and Thermal Behaviour of Starch-Urea Based Biodegradable Polymer and Its Polymer Metal Complexes

PubMed Central

Malik, Ashraf; Parveen, Shadma; Ahamad, Tansir; Alshehri, Saad M.; Singh, Prabal Kumar; Nishat, Nahid

2010-01-01

A starch-urea-based biodegradable coordination polymer modified by transition metal Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) was prepared by polycondensation of starch and urea. All the synthesized polymeric compounds were characterized by Fourier transform-infrared spectroscopy (FT-IR), 1H-NMR spectroscopy, 13C-NMR spectroscopy, UV-visible spectra, magnetic moment measurements, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The results of electronic spectra and magnetic moment measurements indicate that Mn(II), Co(II), and Ni(II) complexes show octahedral geometry, while Cu(II) and Zn(II) complexes show square planar and tetrahedral geometry, respectively. The thermogravimetric analysis revealed that all the polymeric metal complexes are more thermally stable than the parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM standards of biodegradable polymers by CO2 evolution method. PMID:20414461

Synthesis, characterization, antimicrobial, DNA-cleavage and antioxidant activities of 3-((5-chloro-2-phenyl-1H-indol-3-ylimino)methyl)quinoline-2(1H)-thione and its metal complexes

NASA Astrophysics Data System (ADS)

Vivekanand, B.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

2015-01-01

Schiff base 3-((5-chloro-2-phenyl-1H-indol-3-ylimino)methyl)quinoline-2(1H)-thione and its Cu(II), Co(II), Ni(II), Zn(II) and Fe(III), complexes have been synthesized and characterized by elemental analysis, UV-Visible, IR, 1H NMR, 13C NMR and mass spectra, molar conductance, magnetic susceptibility, ESR and TGA data. The ligand and its metal complexes have been screened for their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, antifungal activity against Aspergillus niger and Aspergillus flavus in minimum inhibition concentration (MIC) by cup plate method respectively, antioxidant activity using 1,1-diphenyl-2-picryl hydrazyl (DPPH), which was compared with that of standard drugs vitamin-C and vitamin-E and DNA cleavage activity using calf-thymus DNA.

Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes based on salicylaldehyde-o-aminophenol

NASA Astrophysics Data System (ADS)

Tan, Yu-Xing; Zhang, Zhi-Jian; Liu, Yang; Yu, Jiang-Xi; Zhu, Xiao-Ming; Kuang, Dai-Zhi; Jiang, Wu-Jiu

2017-12-01

Schiff base organotin(IV) complexes C1 ∼ C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ∼ L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have been characterized by IR, UV-Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base ligand and complexes C1 ∼ C5b against five species of cancer cell which are Hela, MCF7, HepG2, Colo205, NCIsbnd H460 were tested respectively, the tests showed that C1 ∼ C5b exhibited significant anticancer activity for the cancer cells in comparison with the ligand, and the activity was greater than carboplatin.

New derivatives of (E,E)-azomethines: Design, quantum chemical modeling, spectroscopic (FT-IR, UV/Vis, polarization) studies, synthesis and their applications: Experimental and theoretical investigations

NASA Astrophysics Data System (ADS)

Sheikhi, Masoome; Shahab, Siyamak; Filippovich, Liudmila; Yahyaei, Hooriye; Dikusar, Evgenij; Khaleghian, Mehrnoosh

2018-01-01

In present work, Polarization, Excited States, FT-IR, 1H, 13C NMR, Trans-Cis (E → Z) Isomerization Properties and Anisotropy of Thermal and Electrical Conductivity of the three new Azomethines dyes such as: 4-((E)-((4-((E)-phenyldiazenyl)phenyl)imino)methyl)benzoic acid (I), 5-phenyl-N-(pyrimidin-2-yl)isoxazole-3-carboxamide (II) and (Z)-1-(4-((E)-((4-phenylcyclopenta-1,4-dien-1-yl)methylene)amino)phenyl)ethanone oxime (III) in the presence of polyvinyl alcohol (PVA) matrix were studied. The absorption spectrum of the I, II and III in dimethylformamide (DMF) solution was calculated. The nature of absorption peaks of the dyes in the UV/Vis spectral regions was interpreted. The molecular HOMO-LUMO, excitation energies and oscillator strengths for E and Z isomers of the I, II and III have also been calculated and presented. Optical Properties of the PVA-films containing these new synthesized dyes have investigated. Polarizing Efficiency (PE) of obtained PVA-film is 97-98% at Stretching Degree (Rs) 3.5. Anisotropy of thermal and electrical conductivity of the PVA-films containing the title compounds was also measured and discussed.

Group 6 metal pentacarbonyl complexes of air-stable primary, secondary, and tertiary ferrocenylethylphosphines.

PubMed

Rabiee Kenaree, Amir; Sauvé, Ethan R; Ragogna, Paul J; Gilroy, Joe B

2016-02-21

The synthesis and characterization of a series of Group 6 metal pentacarbonyl complexes of air stable primary, secondary, and tertiary phosphines containing ferrocenylethyl substituents are reported [M(CO)5L: M = Cr, Mo, W; L = PH2(CH2CH2Fc), PH(CH2CH2Fc)2, P(CH2CH2Fc)3]. The structure and composition of the complexes were confirmed by multinuclear NMR spectroscopy, IR and UV-Vis absorption spectroscopy, mass spectrometry, X-ray crystallography, and elemental analysis. The solid-state structural data reported revealed trends in M-C and M-P bond lengths that mirrored those of the atomic radii of the Group 6 metals involved. UV-Vis absorption spectroscopy and cyclic voltammetry highlighted characteristics consistent with electronically isolated ferrocene units including wavelengths of maximum absorption between 435 and 441 nm and reversible one-electron (per ferrocene unit) oxidation waves between 10 and -5 mV relative to the ferrocene/ferrocenium redox couple. IR spectroscopy confirmed that the σ donating ability of the phosphines increased as ferrocenylethyl substituents were introduced and that the tertiary phosphine ligand described is a stronger σ donor than PPh3 and a weaker σ donor than PEt3, respectively.

Molecular structure activity on pharmaceutical applications of Phenacetin using spectroscopic investigation

NASA Astrophysics Data System (ADS)

Madanagopal, A.; Periandy, S.; Gayathri, P.; Ramalingam, S.; Xavier, S.

2017-01-01

The pharmaceutical compound; Phenacetin was investigated by analyzing FT-IR, FT-Raman and 1H &13C NMR spectra. The hybrid efficient computational calculations performed for computing physical and chemical parameters. The cause of pharmaceutical activity due to the substitutions; carboxylic, methyl and amine groups in appropriate positions on the pedestal compound was deeply investigated. Moreover, 13C NMR and 1H NMR chemical shifts correlated with TMS standard to explain the truth of compositional ratio of base and ligand groups. The bathochromic shift due to chromophores over the energy levels in UV-Visible region was strongly emphasized the Anti-inflammatory chemical properties. The chemical stability was pronounced by the strong kubo gap which showed the occurring of charge transformation within the molecule. The occurrence of the chemical reaction was feasibly interpreted by Gibbs free energy profile. The standard vibrational analysis stressed the active participation of composed ligand groups for the existence of the analgesic as well as antipyretic properties of the Phenacetin compound. The strong dipole interaction energy utilization for the transition among non-vanishing donor and acceptor for composition of the molecular structure was interpreted.

Discovering [superscript 13]C NMR, [superscript 1]H NMR, and IR Spectroscopy in the General Chemistry Laboratory through a Sequence of Guided-Inquiry Exercises

ERIC Educational Resources Information Center

Iler, H. Darrell; Justice, David; Brauer, Shari; Landis, Amanda

2012-01-01

This sequence of three guided-inquiry labs is designed for a second-semester general chemistry course and challenges students to discover basic theoretical principles associated with [superscript 13]C NMR, [superscript 1]H NMR, and IR spectroscopy. Students learn to identify and explain basic concepts of magnetic resonance and vibrational…

Monoterpene Unknowns Identified Using IR, [to the first power]H-NMR, [to the thirteenth power]C-NMR, DEPT, COSY, and HETCOR

ERIC Educational Resources Information Center

Alty, Lisa T.

2005-01-01

A study identifies a compound from a set of monoterpenes using infrared (IR) and one-dimensional (1D) nuclear magnetic resonance (NMR) techniques. After identifying the unknown, each carbon and proton signal can be interpreted and assigned to the structure using the information in the two-dimensional (2D) NMR spectra, correlation spectroscopy…

Synthesis, spectroscopic characterization, DFT studies and antifungal activity of (E)-4-amino-5-[N'-(2-nitro-benzylidene)-hydrazino]-2,4-dihydro-[1,2,4]triazole-3-thione

NASA Astrophysics Data System (ADS)

Joshi, Rachana; Pandey, Nidhi; Yadav, Swatantra Kumar; Tilak, Ragini; Mishra, Hirdyesh; Pokharia, Sandeep

2018-07-01

The hydrazino Schiff base (E)-4-amino-5-[N'-(2-nitro-benzylidene)-hydrazino]-2,4-dihydro-[1,2,4]triazole-3-thione was synthesized and structurally characterized by elemental analysis, FT-IR, Raman, 1H and 13C-NMR and UV-Vis studies. A density functional theory (DFT) based electronic structure calculations were accomplished at B3LYP/6-311++G(d,p) level of theory. A comparative analysis of calculated vibrational frequencies with experimental vibrational frequencies was carried out and significant bands were assigned. The results indicate a good correlation (R2 = 0.9974) between experimental and theoretical IR frequencies. The experimental 1H and 13C-NMR resonance signals were also compared to the calculated values. The theoretical UV-Vis spectral studies were carried out using time dependent-DFT method in gas phase and IEFPCM model in solvent field calculation. The geometrical parameters were calculated in the gas phase. Atomic charges at selected atoms were calculated by Mulliken population analysis (MPA), Hirshfeld population analysis (HPA) and Natural population analysis (NPA) schemes. The molecular electrostatic potential (MEP) map was calculated to assign reactive site on the surface of the molecule. The conceptual-DFT based global and local reactivity descriptors were calculated to obtain an insight into the reactivity behaviour. The frontier molecular orbital analysis was carried out to study the charge transfer within the molecule. The detailed natural bond orbital (NBO) analysis was performed to obtain an insight into the intramolecular conjugative electronic interactions. The titled compound was screened for in vitro antifungal activity against four fungal strains and the results obtained are explained through in silico molecular docking studies.

Crystal structure, spectral and thermal properties of 1,2-bis[2-(4,4,4-trifluoro-1-hydroxy-3-oxobut-1-enyl)phenoxy]-ethane and luminescent properties of its complexes with Al(III) and Eu(III)

NASA Astrophysics Data System (ADS)

Khamidullina, Liliya A.; Obydennov, Konstantin L.; Slepukhin, Pavel A.; Puzyrev, Igor S.

2016-12-01

Describing the crystal structure, packing, FT-IR, UV-Vis and NMR spectra and thermal properties of new polydentate O-ligand based on aryl-β-diketone moieties connected by ethylene glycol spacer is the subject of this article. The results of IR, UV-Vis and 1H NMR spectroscopy as well X-ray crystallography of 1,2-bis[2-(4,4,4-trifluoro-1-hydroxy-3-oxobut-1-enyl)phenoxy]-ethane (BTFPE) indicate that the compound exists in solution and in solid as enol. The crystal structure analysis shows that BTFPE has C2/c group of the monoclinic system. Typical S(6) intramolecular hydrogen bond occurs in each 1,3-diketo moiety. This bond is asymmetric and the H atom is closest to the O atom adjacent to the phenyl ring. The packing of the crystal is sustained by numerous Csbnd H⋯O, Osbnd H⋯F, Csbnd H⋯F interactions. In the crystal, supramolecular zig-zag chains are formed along the c-axis. Short contacts interconnect the molecules into a two-dimensional layered structure wherein each molecule is node between chains. According to the thermal investigation this compound is stable up to 200 °C in air atmosphere, above this temperature it decomposes. Photoluminescent properties of aluminum(III) and europium(III) complexes of BTFPE were evaluated in chloroform solution and in the solid state. Aluminum complex of BTFPE shows blue luminescence with maximum at 445 nm. Europium complex exhibits intense red color luminescence at 613 nm from central Eu(III) ion through the excitation of the ligand.

Exploring the relevance of gas-phase structures to biology: cold ion spectroscopy of the decapeptide neurokinin A.

PubMed

Pereverzev, A Y; Boyarkin, O V

2017-02-01

Linking the intrinsic tertiary structures of biomolecules to their native geometries is a central prerequisite for making gas-phase studies directly relevant to biology. The isolation of molecules in the gas phase eliminates hydrophilic interactions with solvents, to some extent mimicking a hydrophobic environment. Intrinsic structures therefore may resemble native ones for peptides that in vivo reside in a hydrophobic environment (e.g., binding pockets of receptors). In this study, we investigate doubly protonated neurokinin A (NKA) using IR-UV double resonance cold ion spectroscopy and find only five conformers of this decapeptide in the gas phase. In contrast, NMR data show that in aqueous solutions, NKA exhibits high conformational heterogeneity, which reduces to a few well-defined structures in hydrophobic micelles. Do the gas-phase structures of NKA resemble these native structures? The IR spectra reported here allow the validation of future structural calculations that may answer this question.

Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

NASA Astrophysics Data System (ADS)

Refat, Moamen S.

2013-03-01

Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

Electrochemical and spectroelectrochemical study on novel non-peripherally tetra 1,2,4-triazole substituted phthalocyanines

NASA Astrophysics Data System (ADS)

Demirbaş, Ümit; Akyüz, Duygu; Akçay, Hakkı Türker; Koca, Atıf; Bekircan, Olcay; Kantekin, Halit

2018-03-01

In the present study novel tetra 4-(4-fluorophenyl)-5-(4-methoxyphenyl)-4H-1,2,4-triazole-3-thio substituted non-peripherally metal free (4), zinc(II) (5), lead (II) (6) and copper(II) (7) phthalocyanines were synthesized. The obtained novel compounds were characterized by a combination of FT-IR, 1H NMR, UV-Vis and MALDI-TOF techniques. The redox properties of the complexes have been investigated via cyclic voltammetry, square wave voltammetry and in situ spectroelectrochemistry. The compounds displayed ring-based, reversible and/or quasi-reversible reduction and oxidation processes and aggregation of the complexes influenced the redox character of the processes. The color changes during the redox processes of metallo phthalocyanine were recorded by in-situ spectroelectrochemical measurements. In situ UV-vis spectroelectrochemical measurements, which was associated with color change of the complexes, showed their applicability in the fields of the electrochemical technologies.

Molecular structure and spectroscopic investigation of sodium(E)-2-hydroxy-5-((4-sulfonatophenyl)diazenyl)benzoate: A DFT study

NASA Astrophysics Data System (ADS)

Shahab, Siyamak; Kumar, Rakesh; Darroudi, Mahdieh; Yousefzadeh Borzehandani, Mostafa

2015-03-01

Quantum-chemical calculations using the Density Functional Theory (DFT) approach for structural analysis of new azodye sodium(E)-2-hydroxy-5-((4-sulfonatophenyl)diazenyl) (trans isomer) is carried out using B3LYP methods with 6-31G∗ basis set. The comparison of measured UV-Vis data, IR and NMR spectra of the molecule with the experimental data were also described which allowed assignment of major spectral features of title molecule. The optimized geometrical parameters obtained by B3LYP methods show a good agreement with experimental data. On the basis of polyvinyl alcohol (PVA) and the dichroic synthesized dye polarizer absorbing in the UV region of the spectrum (λmax = 353 nm) with the effect of polarization in the absorption maximum 96% was developed. The spectral-polarization parameters of stretched PVA-films were calculated.

Synthesis, spectroscopic properties and theoretical studies of bis-Schiff bases derived from polyamine and pyrazolones.

PubMed

Ren, Tiegang; Liu, Shuyun; Li, Guihui; Zhang, Jinglai; Guo, Jia; Li, Weijie; Yang, Lirong

2012-11-01

A series of novel bis-Schiff base were synthesized from 1-aryl-3-methyl-4-benzoyl-5-pyrazolones and diethylenetriamine (or triethylenetetramine) as the starting materials. All of these bis-Schiff bases were characterized by means of NMR, IR, and MS. The UV-vis absorption spectra and fluorescent spectra of these bis-Schiff bases were also measured. Moreover, the B3LYP/6-31G(d) method was used to optimize the ground state geometry of the bis-Schiff bases; and the UV-vis spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVDZ basis set of TD-B3LYP method. It has been found that all of these bis-Schiff bases show a remarkable absorption peak in a wavelength range of 270-340 nm; and their maximum emission peaks are around 348 nm. Copyright © 2012 Elsevier B.V. All rights reserved.

Mixed-ligand Ru(II) complexes with 2,2'-bipyridine and aryldiazo-beta-diketonato auxillary ligands: synthesis, physico-chemical study and antitumour properties.

PubMed

Mishra, Lallan; Yadaw, Ajay K; Bhattacharya, Subrato; Dubey, Santosh K

2005-05-01

The complexes of Ru(II)-2,2'-bipyridyl with substituted diazopentane-2,4-diones (L1H-L5H) were synthesized and characterized by elemental analyses, conductance, FAB (fast atom bombardment) mass and spectral (IR, UV/Vis (UV/visible), NMR) studies. Molecular geometry optimization of the complexes was also made. None of the complexes luminesce. However, facilitated oxidation of Ru(II) to Ru(III) was evidenced from their lower reduction potential data. The ligands and their complexes were tested for their antitumour activity against a variety of tumour cell lines. Though activity is found to vary with the type of tumour cell lines used, yet complex 5 with naphtyldiazopentane-2,4-dione as co-ligand was found to be a potential compound as it showed in general significant activity against all cell lines studied.

Structure Characterization and Lead Detoxification Effect of Carboxymethylated Melanin Derived from Lachnum Sp.

PubMed

Zong, Shuai; Li, Lan; Li, Jinglei; Shaikh, Farnaz; Yang, Liu; Ye, Ming

2017-06-01

In the present study, an intracellular melanin, named LIM205, was separated from Lachnum YM205 mycelia and was purified on a Sephadex G-15 column. The molecular weight of LIM205 was determined as 522 Da, and its molecular formula was speculated as C 28 H 14 N 2 O 7 S. The possible chemical structure of LIM205 was determined according to the results of Fourier transform infrared (FT-IR), 1 H NMR, 13 C NMR, and pyrolysis/GC-MS analysis. With the aim to increase its water solubility, its carboxymethylated derivative, named CLIM205, was formed by the substitution of hydrogen atoms in LIM205 with one, two, and three carboxymethylate groups. FT-IR, UV, and ESI-MS analysis demonstrated that the carboxymethylate groups were conjugated onto LIM205. The lead detoxification activities of LIM205 and CLIM205 had also been investigated. In vivo test showed that both LIM205 and CLIM205 reduced the tissue lead concentration, enhanced lead excretion, and reversed lead-induced alterations in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) concentrations in mice, with CLIM205 showed better efficacy. The study indicates that LIM205 and CLIM205 have significant lead detoxification effect which will contribute to solve related problems.

KK parity in warped extra dimension

NASA Astrophysics Data System (ADS)

Agashe, Kaustubh; Falkowski, Adam; Low, Ian; Servant, Géraldine

2008-04-01

We construct models with a Kaluza-Klein (KK) parity in a five-dimensional warped geometry, in an attempt to address the little hierarchy problem present in setups with bulk Standard Model fields. The lightest KK particle (LKP) is stable and can play the role of dark matter. We consider the possibilities of gluing two identical slices of AdS5 in either the UV (IR-UV-IR model) or the IR region (UV-IR-UV model) and discuss the model-building issues as well as phenomenological properties in both cases. In particular, we find that the UV-IR-UV model is not gravitationally stable and that additional mechanisms might be required in the IR-UV-IR model to address flavor issues. Collider signals of the warped KK parity are different from either the conventional warped extra dimension without KK parity, in which the new particles are not necessarily pair-produced, or the KK parity in flat universal extra dimensions, where each KK level is nearly degenerate in mass. Dark matter and collider properties of a TeV mass KK Z gauge boson as the LKP are discussed.

Evaluation of the structural, electronic, topological and vibrational properties of N-(3,4-dimethoxybenzyl)-hexadecanamide isolated from Maca (Lepidium meyenii) using different spectroscopic techniques

NASA Astrophysics Data System (ADS)

Chain, Fernando; Iramain, Maximiliano Alberto; Grau, Alfredo; Catalán, César A. N.; Brandán, Silvia Antonia

2017-01-01

N-(3,4-dimethoxybenzyl)-hexadecanamide (DMH) was characterized by using Fourier Transform infrared (FT-IR) and Raman (FT-Raman), Ultraviolet- Visible (UV-Visible) and Hydrogen and Carbon Nuclear Magnetic Resonance (1H and 13C NMR) spectroscopies. The structural, electronic, topological and vibrational properties were evaluated in gas phase and in n-hexane employing ONIOM and self-consistent force field (SCRF) calculations. The atomic charges, molecular electrostatic potentials, stabilization energies and topological properties of DMH were analyzed and compared with those calculated for N-(3,4-dimethoxybenzyl)-acetamide (DMA) in order to evaluate the effect of the side chain on the properties of DMH. The reactivity and behavior of this alkamide were predicted by using the gap energies and some descriptors. Force fields and the corresponding force constants were reported for DMA only in gas phase and n-hexane due to the high number of vibration normal modes showed by DMH, while the complete vibrational assignments are presented for DMA and both forms of DMH. The comparisons between the experimental FTIR, FT-Raman, UV-Visible and 1H and 13C NMR spectra with the corresponding theoretical ones showed a reasonable concordance.

Preparation, characterization and binding behaviors of host-guest inclusion complexes of metoclopramide hydrochloride with α- and β-cyclodextrin molecules

NASA Astrophysics Data System (ADS)

Barman, Siti; Barman, Biraj Kumar; Roy, Mahendra Nath

2018-03-01

The supramolecular interaction of metoclopramide hydrochloride (MP) with α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) has been inspected by ultraviolet-visible (UV-vis) light, infra-red (IR) light, fluorescence and 1H NMR spectroscopy. The formation of an inclusion complex greatly affects the physical-chemical properties of the guest molecules, such as solubility, chemical reactivity and the spectroscopic and electrochemical properties. Thus the changes in the spectral properties and physico-chemical properties confirm the inclusion complex formation. Surface tension, conductivity studies and Job's plot indicate a 1: 1 stoichiometry of the MP:CD host-guest inclusion complexes. The binding/association constants have been evaluated by both UV-Vis and fluorescence spectroscopic study indicating a higher degree of encapsulation for β-cyclodextrin (β-CD). Furthermore, the negative value of thermodynamic parameter (ΔG°) of the host-guest system suggests that the inclusion process proceeded spontaneously at 298.15 K. Based on the NMR data, the plausible mode of interaction of MP:α-CD and MP:β-CD complexes were proposed, which suggested that lipophilic aromatic ring of the MP entered into the cavity of CDs from the wider side, with the amide (sbnd CONH) and methoxy (-OMe) residues inside the CD cavity.

Experimental and theoretical elucidation of structural and antioxidant properties of vanillylmandelic acid and its carboxylate anion

NASA Astrophysics Data System (ADS)

Dimić, Dušan; Milenković, Dejan; Ilić, Jelica; Šmit, Biljana; Amić, Ana; Marković, Zoran; Dimitrić Marković, Jasmina

2018-06-01

Vanillylmandelic acid (VMA), an important metabolite of catecholamines that is routinely screened as tumor marker, was investigated by the various spectroscopic techniques (IR, Raman, UV-Vis, antioxidant decolorization assay and NMR). Structures optimized by the employment of five common functionals (M05-2X, M06-2X, B3LYP, CAM-B3LYP, B3LYP-D3) were compared with the crystallographic data. The M05-2X functional reproduced the most reliable experimental bond lengths and angles (correlation coefficient >0.999). The importance of intramolecular hydrogen bonds for structural stability was discussed and quantified by the NBO analysis. The most prominent bands in vibrational spectrum were analyzed and compared to the experimental data. The positions of the carbon and hydrogen atoms in NMR spectra were well reproduced. The differences in UV-Vis spectrum were investigated by adding the explicit solvent and by performing NBO and QTAIM analyses. The discrepancy in the two spectra of about 50 nm could be explained by the solvent effect on carboxyl group. The most probable antioxidant activity mechanism was discussed for VMA and its carboxylate anion. The Molecular Docking study with the C - reactive protein additionally proved that variety of functional groups present in VMA and its anion allowed strong hydrogen and hydrophobic interactions.

Synthesis and molecular structure of a zinc complex of the vitamin K3 analogue phthiocol

NASA Astrophysics Data System (ADS)

Kathawate, Laxmi; Sproules, Stephen; Pawar, Omkar; Markad, Ganesh; Haram, Santosh; Puranik, Vedavati; Salunke-Gawali, Sunita

2013-09-01

The complex [Zn(phthiocol)2(H2O)2]; 1, where phthiocol is 2-hydroxy-3-methyl-1,4-naphthoquinone, has been synthesized and characterized by elemental analysis, FT-IR, 1H NMR, UV-vis spectroscopy, thermogravimetric (TG) analysis, electrochemical and single crystal X-ray diffraction studies. The νCO stretch shifts to lower frequencies upon complexation of phthiocol to Zn2+. 1H NMR spectra show an upfield shift of the benzenoid ring protons in 1. There is a bathochromic shift of the LMCT band in the UV-vis spectra of 1. Single crystal X-ray structure of 1 show distorted octahedral geometry around Zn2+. Two phthiocol ligands are in plane with the metal, while water molecules are trans to this plane. Coordination of deprotonated phthiocol ligands is 'trans, trans' to Zn2+. Intra as well as intermolecular interactions are observed in 1. Molecules of 1 show three dimensional network through CH⋯O and OH⋯O interactions. Additional anodic peaks are observed in cyclic voltammogram of phthiocol ligand due to oxidation of reduced species formed during reduction. One-electron reduction of 1 is shown to be reversible and DFT studies define this redox event as ligand-centered.

Change in the Chemical Profile of Mangifera indica Leaves after their Metabolism in the Tropidacris collaris Grasshopper.

PubMed

da Silva, Rodolfo R; Moraes, Marcilio M; Camara, Claudio A G; Ramos, Clécio S

2015-11-01

This present work addresses research on the discovery of new compounds from natural sources. It is based on a study of Mangifera indica leaf metabolism by the Tropidacris collaris grasshopper. We found that the grasshopper hydrolyzed the flavonoid isoquercitrin to quercetin when the O-glycosidic bond was broken and sugar released as a probable energy source for the insect. There was not, however, hydrolysis of the major compound in the leaves, mangiferin, which contains the C-glycosidic bond. All compounds were isolated and their chemical structure determined by UV, IR, MS, 1H and 13C NMR.

Pestalactams A-C: novel caprolactams from the endophytic fungus Pestalotiopsis sp.

PubMed

Davis, Rohan A; Carroll, Anthony R; Andrews, Katherine T; Boyle, Glen M; Tran, Truc Linh; Healy, Peter C; Kalaitzis, John A; Shivas, Roger G

2010-04-21

Chemical investigations of a fermentation culture from the endophytic fungus Pestalotiopsis sp. yielded three novel caprolactams, pestalactams A-C (). The structures of were determined by analysis of 1D and 2D-NMR, UV, IR, and MS data. The structure of pestalactam A was confirmed following single crystal X-ray diffraction analysis. Pestalactams A-C are the first C-7 alkylated caprolactam natural products to be reported. Pestalactams A () and B () were tested against two different strains of the malaria parasite Plasmodium falciparum (3D7 and Dd2), and the mammalian cell lines, MCF-7 and NFF, and showed modest in vitro activity in all assays.

Synthesis of electroactive tetraaniline grafted polyethylenimine for tissue engineering

NASA Astrophysics Data System (ADS)

Dong, Shilei; Han, Lu; Cai, Muhang; Li, Luhai; Wei, Yan

2015-07-01

Tetraaniline grafted polyethylenimine (AT-PEI) was successfully synthesized in this study. Proton Nuclear Magnetic Resonance (1H NMR) Spectroscopy was used to determine the structure of carboxyl-capped aniline tetramer (AT-COOH) and AT-PEI. UV-Vis spectroscopy and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize the absorption spectrum of the obtained AT-PEI samples. The morphology of AT-PEI copolymers in aqueous solution was determined by Scanning electron microscope (SEM). Moreover, AT-PEI copolymers demonstrated excellent solubility in aqueous solution and possessed electroactivity by cyclic voltammogram (CV) curves, which showed its potential application in the field of tissue engineering.

Synthesis, crystal growth, structural, thermal and optical properties of naphthalene picrate an organic NLO material.

PubMed

Chandramohan, A; Bharathikannan, R; Kandavelu, V; Chandrasekaran, J; Kandhaswamy, M A

2008-12-01

Crystalline substance of naphthalene picrate (NP) was synthesized and single crystals were grown using slow evaporation solution growth technique. The solubility of the naphthalene picrate complex was estimated using different solvents such as chloroform and benzene. The material was characterized by elemental analysis, powder X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and fourier transform-infrared (FT-IR) techniques. The electronic absorption was studied through UV-vis spectrophotometer. Thermal behavior and stability of the crystal were studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The second harmonic generation (SHG) of the material was confirmed using Nd:YAG laser.

Colorimetric detection of hydrogen peroxide by dioxido-vanadium(V) complex containing hydrazone ligand: synthesis and crystal structure

NASA Astrophysics Data System (ADS)

Kurbah, Sunshine D.; Syiemlieh, Ibanphylla; Lal, Ram A.

2018-03-01

Dioxido-vanadium(V) complex has been synthesized in good yield, the complex was characterized by IR, UV-visible and 1H NMR spectroscopy. Single crystal X-ray crystallography techniques were used to assign the structure of the complex. Complex crystallized with monoclinic P21/c space group with cell parameters a (Å) = 39.516(5), b (Å) = 6.2571(11), c (Å) = 17.424(2), α (°) = 90, β (°) = 102.668(12) and γ (°) = 90. The hydrazone ligand is coordinate to metal ion in tridentate fashion through -ONO- donor atoms forming a distorted square pyramidal geometry around the metal ion.

Highly soluble 3,4-(dimethoxyphenylthio) substituted phthalocyanines: Synthesis, photophysical and photochemical studies

NASA Astrophysics Data System (ADS)

Öztürk, Cansu; Erdoğmuş, Ali; Durmuş, Mahmut; Uğur, Ahmet Lütfi; Kılıçarslan, Fatma Aytan; Erden, İbrahim

2012-02-01

The synthesis of a new 3,4-(dimethoxyphenylthio) substituted phthalonitrile ( 1) and its soluble metal free ( 2), zinc (II) ( 3), oxo-titanium (IV) ( 4) and nickel (II) ( 5) phthalocyanine derivatives are reported for the first time. The new compounds have been characterized by elemental analysis, FT-IR, 1H NMR, UV-Vis, fluorescence spectroscopies and mass spectra. General trends are described for fluorescence, photodegradation and singlet oxygen quantum yields and fluorescence lifetimes of oxo-titanium (IV) and zinc (II) phthalocyanine compounds in dimethylsulfoxide (DMSO). The effects of the metal ion on the photophysical and photochemical parameters for these phthalocyanines ( 3 and 4) are also reported.

ARTICLES: Microwave Assisted Synthesis of a New Triplet Iridium(III) Pyrazine Complex

NASA Astrophysics Data System (ADS)

Wu, Qiu-hua; Wang, Chuan-hong; Song, Xi-ming; Zhang, Guo-lin

2010-06-01

A new cyclometalated iridium(III) complex Ir(DPP)3 (DPP = 2,3-diphenylpyrazine) was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confirmed by elemental analysis, 1H NMR, and mass spectroscopy. The UV-Vis absorption and photoluminescent properties of the complex were investigated. The complex shows strong 1MLCT (singlet metal to ligand charge-transfer) and 3MLCT (triplet metal to ligand charge-transfer) absorption at 382 and 504 nm, respectively. The complex also shows strong photoluminescence at 573 nm at room temperature. These results suggest the complex to be a promising phosphorescent material.

Synthesis and characterization of a new porphyrin-polyoxometalate hybrid material and investigation of its catalytic activity.

PubMed

Araghi, Mehdi; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammdpoor-Baltork, Iraj

2012-03-14

In the present work, the preparation of a new organic-inorganic hybrid material in which tetrakis(p-aminophenylporphyrin) is covalently linked to a Lindqvist structure of polyoxometalate, is reported. This new porphyrin-polyoxometalate hybrid material was characterized by (1)H NMR, FT-IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided spectral data of the synthesis of this compound. Cyclic voltammetry showed the influence of the porphyrin on the redox process of the polyoxometalate. The catalytic activity of this hybrid material was investigated in the alkene epoxidation with NaIO(4).

Spectral, coordination and thermal properties of 5-arylidene thiobarbituric acids

NASA Astrophysics Data System (ADS)

Masoud, Mamdouh S.; El-Marghany, Adel; Orabi, Adel; Ali, Alaa E.; Sayed, Reham

2013-04-01

Synthesis of 5-arylidine thiobarbituric acids containing different functional groups with variable electronic characters were described and their Co2+, Ni2+ and Cu2+ complexes. The stereochemistry and mode of bonding of 5-(substituted benzylidine)-2-TBA complexes were achieved based on elemental analysis, spectral (UV-VIS, IR, 1H NMR, MS), magnetic susceptibility and conductivity measurements. The ligands were of bidentate and tridentate bonding through S, N and O of pyrimidine nucleolus. All complexes were of octahedral configuration. The thermal data of the complexes pointed to their stability. The mechanism of the thermal decomposition is discussed. The thermodynamic parameters of the dissociation steps were evaluated and discussed.

Polypropionate lactones of deoxysugars glycosides from slime mold Lycogala epidendrum.

PubMed

Rezanka, Tomás; Dvoráková, Radmila

2003-08-01

Two novel polypropionate lactone glycosides (1 and 2, i.e. lycogalinosides A and B) were isolated from the slime mold Lycogala epidendrum. Their structures, including the absolute configurations of the hydroxyl and methyls groups, were determined by means of extensive spectroscopic data such as mass, IR, UV, and 1D and 2D NMR spectra and chemical degradation followed by spectroscopic and chromatographic analysis. Compounds 1 and 2 are unique in structure containing a 2-deoxy-alpha-L-fucopyranosyl-(1-4)-6-deoxy-beta-D-gulopyranosyl unit and a beta-D-olivopyranosyl-(1-4)-beta-D-fucopyranosyl unit, respectively, and showed growth inhibitory activities against Gram-positive bacteria.

Three new biflavonoids from the branches and leaves of Cephalotaxus oliveri and their antioxidant activity.

PubMed

Xiao, Shu; Mu, Zhen-Qiang; Cheng, Chun-Ru; Ding, Jie

2018-03-15

Three new biflavonoids, named oliveriflavones A-C (1-3), together with two known flavonoids (quercetin (4) and rutin (5)), were isolated from the endangered plant Cephalotaxus oliveri. The chemical structures of these compounds were elucidated by comprehensive spectroscopic methods including NMR, HRESIMS, IR, UV, and CD spectra. Compounds 1-5 were first isolated from the genus Cephalotaxus. All the compounds were tested for their antioxidant activity. Compounds 4 and 5 showed excellent activity with IC 50 values of 0.03 ± 0.06 μM and 0.02 ± 0.10 μM, respectively.

The aggregation of the merocyanine dyes, depending of the type of the counterions.

PubMed

Kolev, Tsonko; Koleva, Bojidarka B; Stoyanov, Stanimir; Spiteller, Michael; Petkov, Ivan

2008-10-01

Counterions affect on the substructures formation in the case of the merocyanine dye, 1-methyl-4-[2-(4-hydroxyphenyl)ethenyl)]piridinium] hydrogensquarate both in gas and condense phase. Spectroscopically and structural elucidation of these aggregates have been performed, using solid-state conventional and linear-polarized IR-spectroscopy of oriented colloids as a nematic liquid crystal suspension, UV-vis spectroscopy, HPLC tandem ESI mass spectrometry, 1H and 13C NMR, TGV and DSC. Quantum chemical DFT calculations have been carried out as well. Experimental and theoretical data are compared with analogous ones of corresponding iodide salt of dye studied.

Transition metal complexes of quinolino[3,2-b]benzodiazepine and quinolino[3,2-b]benzoxazepine: synthesis, characterization, and antimicrobial studies.

PubMed

Basavaraju, B; Naik, Halehatty S Bhojya; Prabhakara, Mustur C

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand.

[Phenanthrene constituents from rhizome of Arundina graminifolia].

PubMed

Liu, Mei-feng; Ding, Yi; Zhang, Dong-ming

2005-03-01

To isolate and elucidate the constituents from rhizome of Arundina graminifolia. Theconstituents were extracted with 95% alcohol and isolated by chromatography on silica gel, Sephedax LH-20. The structures were determined by UV, IR, NMR and MS spectral analysis. Five phenanthrene constituents were identified as 7-hydroxy-2, 4-dimethoxy-9, 10-dihydrophenanthrene( I ), 4, 7-dihydroxy-2-methoxy-9, 10-dihydrophenanthrene ( II ), 2, 7-dihydroxy-4-methoxy-9, 10-dihydrophenanthrene ( III ), 7-hydroxy-2-methoxyphenanthrene-1,4-dione ( IV ), 7-hydroxy-2-methoxy-9, 10-dihydrophenanthrene-1,4-dione (V), respectively. All compounds were isolated from rhizome of A. graminifolia for the first time.

Phenylethanoid glycosides from Phlomis integrifolia Hub.-Mor.

PubMed

Saracoglu, Iclal; Varel, Mehtap; Hada, Junko; Hada, Noriyasu; Takeda, Tadahiro; Donmez, Ali A; Calis, Ihsan

2003-01-01

Two new phenylethanoid glycosides integrifoliosides A (2) and B (3), along with a known phenylethanoid glycoside alyssonoside (1) and a flavone glucoside chrysoeriol-7-O-beta-D-glucopyranoside (4) were isolated from the aerial parts of Phlomis integrifolia. The structures of the new compounds were identified as 3,4-dihydroxy-beta-phenylethoxy-O-beta-D-apiofuranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 3)-4-O-feruloyl-beta-D-glucopyranoside (2) and 3-hydroxy-4-methoxy-beta-phenylethoxy-O-beta-D-apiofuranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 3)-4-O-feruloyl-beta-D-glucopyranoside (3), on the basis of spectroscopic (UV, IR, 1D- and 2D-NMR, and HR-FABMS) methods.

[Synthesis, solubility, lipids-lowering and liver-protection activities of sulfonated formononetin].

PubMed

Wang, Qiu-ya; Meng, Qing-hua; Zhang, Zun-ting; Tian, Zhen-jun; Liu, Hui

2009-04-01

A water-soluble compound, sodium formononetin-3'-sulfonate with good lipid-lowering and liver-protection activities was synthesized. It was synthesized by sulfonation reaction, and its structure was characterized by IR, NMR and elemental analyses. The solubility of sodium formononetin-3'-sulfonate in water and n-octanol/water partition coefficient were determined by UV spectrophotometry. The lipid-lowering and liver-protection activities of sodium formononetin-3'-sulfonate were tested by using rat's high fat model induce by feeding with high fat food. The results showed that sodium formononetin-3'-sulfonate not only had favorable water, solubility but also had good lipid-lowering and liver-protection activities.

Investigation of silicate mineral sanidine by vibrational and NMR spectroscopic methods

NASA Astrophysics Data System (ADS)

Anbalagan, G.; Sankari, G.; Ponnusamy, S.; kumar, R. Thilak; Gunasekaran, S.

2009-10-01

Sanidine, a variety of feldspar minerals has been investigated through optical absorption, vibrational (IR and Raman), EPR and NMR spectroscopic techniques. The principal reflections occurring at the d-spacings, 3.2892, 3.2431, 2.9022 and 2.6041 Å confirm the presence of sanidine structure in the mineral. Sanidine shows five prominent characteristic infrared absorption bands in the region 1200-950, 770-720, 590-540 and 650-640 cm -1. The Raman spectrum shows the strongest band at 512 cm -1 characteristic of the feldspar structure, which contains four membered rings of tetrahedra. The UV-vis-NIR absorption spectrum had strong absorption features at 6757, 5780 and 5181 cm -1 due to the combination of fundamental OH- stretching. The bands at 11236 and 8196 cm -1and the strong, well-defined band at (30303 cm -1 attest the presence of Fe 2+ and Fe 3+, respectively, in the sample. The signals at g = 4.3 and 3.7 are interpreted in terms of Fe 3+ at two distinct tetrahedral positions Tl and T2 of the monoclinic crystal structure The 29Si NMR spectrum shows two peaks at -97 and -101 ppm corresponding to T2 and T1, respectively, and one peak in 27Al NMR for Al(IV).

Investigation of silicate mineral sanidine by vibrational and NMR spectroscopic methods.

PubMed

Anbalagan, G; Sankari, G; Ponnusamy, S; Kumar, R Thilak; Gunasekaran, S

2009-10-01

Sanidine, a variety of feldspar minerals has been investigated through optical absorption, vibrational (IR and Raman), EPR and NMR spectroscopic techniques. The principal reflections occurring at the d-spacings, 3.2892, 3.2431, 2.9022 and 2.6041 A confirm the presence of sanidine structure in the mineral. Sanidine shows five prominent characteristic infrared absorption bands in the region 1200-950, 770-720, 590-540 and 650-640 cm(-1). The Raman spectrum shows the strongest band at 512 cm(-1) characteristic of the feldspar structure, which contains four membered rings of tetrahedra. The UV-vis-NIR absorption spectrum had strong absorption features at 6757, 5780 and 5181 cm(-1) due to the combination of fundamental OH- stretching. The bands at 11236 and 8196 cm(-1)and the strong, well-defined band at (30303 cm(-1) attest the presence of Fe(2+) and Fe(3+), respectively, in the sample. The signals at g = 4.3 and 3.7 are interpreted in terms of Fe(3+) at two distinct tetrahedral positions Tl and T2 of the monoclinic crystal structure The (29)Si NMR spectrum shows two peaks at -97 and -101 ppm corresponding to T2 and T1, respectively, and one peak in (27)Al NMR for Al(IV).

Study of interaction between ionic liquids and orange G in aqueous solution with UV-vis spectroscopy and conductivity meter.

PubMed

Zha, Jin-Ping; Zhu, Meng-Ting; Qin, Li; Wang, Xin-Hong

2018-05-05

The interactions between Orange G (OG) with three kinds of ionic liquid surfactants (C 10 mimBF 4 , C 12 mimBF 4 , C 16 mimBF 4 ) and CTAB were studied with UV-Vis spectra and conductivity measurements. The systematic changes in UV-Vis spectra with an increase of carbon-chain length may be observed in presence of OG. They correspond to CMC of every system, respectively, and the CMCs of four systems have exhibit the decrease of CMCs compared to pure surfactant. The binding constants are calculated from the results of conductivity measurements in the order of C 16 mimBF 4 >CTAB>C 12 mimBF 4 >C 10 mimBF 4 . Furthermore, system behaviors presented significant association of complex formation and micelles formation, i.e. the change in UV-Vis spectra before and after the formation of micelles in mixed systems. In addition, Fourier-transform infrared (FT-IR) spectroscopy and 1 H NMR analysis further confirmed that the complexes are formed by hydrogen bond and van der Waal force. These findings could provide scientific guidance for extraction and separation of dyes. Copyright © 2018 Elsevier B.V. All rights reserved.

Study of interaction between ionic liquids and orange G in aqueous solution with UV-vis spectroscopy and conductivity meter

NASA Astrophysics Data System (ADS)

Zha, Jin-Ping; Zhu, Meng-Ting; Qin, Li; Wang, Xin-Hong

2018-05-01

The interactions between Orange G (OG) with three kinds of ionic liquid surfactants (C10mimBF4, C12mimBF4, C16mimBF4) and CTAB were studied with UV-Vis spectra and conductivity measurements. The systematic changes in UV-Vis spectra with an increase of carbon-chain length may be observed in presence of OG. They correspond to CMC of every system, respectively, and the CMCs of four systems have exhibit the decrease of CMCs compared to pure surfactant. The binding constants are calculated from the results of conductivity measurements in the order of C16mimBF4 > CTAB > C12mimBF4 > C10mimBF4. Furthermore, system behaviors presented significant association of complex formation and micelles formation, i.e. the change in UV-Vis spectra before and after the formation of micelles in mixed systems. In addition, Fourier-transform infrared (FT-IR) spectroscopy and 1H NMR analysis further confirmed that the complexes are formed by hydrogen bond and van der Waal force. These findings could provide scientific guidance for extraction and separation of dyes.

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blasberger, Avi; Behar, Ehud; Perets, Hagai B.

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorptionmore » and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.« less

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

NASA Astrophysics Data System (ADS)

Blasberger, Avi; Behar, Ehud; Perets, Hagai B.; Brosch, Noah; Tielens, Alexander G. G. M.

2017-02-01

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μm IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μm IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ˜15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ˜15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

Effect of UV-A and UV-B irradiation on the metabolic profile of aqueous humor in rabbits analyzed by 1H NMR spectroscopy.

PubMed

Tessem, May-Britt; Bathen, Tone F; Cejková, Jitka; Midelfart, Anna

2005-03-01

This study was conducted to investigate metabolic changes in aqueous humor from rabbit eyes exposed to either UV-A or -B radiation, by using (1)H nuclear magnetic resonance (NMR) spectroscopy and unsupervised pattern recognition methods. Both eyes of adult albino rabbits were irradiated with UV-A (366 nm, 0.589 J/cm(2)) or UV-B (312 nm, 1.667 J/cm(2)) radiation for 8 minutes, once a day for 5 days. Three days after the last irradiation, samples of aqueous humor were aspirated, and the metabolic profiles analyzed with (1)H NMR spectroscopy. The metabolic concentrations in the exposed and control materials were statistically analyzed and compared, with multivariate methods and one-way ANOVA. UV-B radiation caused statistically significant alterations of betaine, glucose, ascorbate, valine, isoleucine, and formate in the rabbit aqueous humor. By using principal component analysis, the UV-B-irradiated samples were clearly separated from the UV-A-irradiated samples and the control group. No significant metabolic changes were detected in UV-A-irradiated samples. This study demonstrates the potential of using unsupervised pattern recognition methods to extract valuable metabolic information from complex (1)H NMR spectra. UV-B irradiation of rabbit eyes led to significant metabolic changes in the aqueous humor detected 3 days after the last exposure.

Molecular vibrational investigation [FT-IR, FT-Raman, UV-Visible and NMR] on Bis(thiourea) Nickel chloride using HF and DFT calculations.

PubMed

Anand, S; Sundararajan, R S; Ramachandraraja, C; Ramalingam, S; Durga, R

2015-03-05

In the present research work, the FT-IR, FT-Raman spectra of the Bis(thiourea) Nickel chloride (BTNC) were recorded and analyzed. The observed fundamental frequencies in finger print and functional group regions were assigned according to their uniqueness region. The computational calculations were carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The present organo-metallic compound was made up of covalent and coordination covalent bonds. The modified vibrational pattern of the complex molecule associated with ligand group was analyzed. Furthermore, the (13)C NMR and (1)H NMR spectral data were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP/6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A investigation on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Organic Spectroscopy Laboratory: Utilizing IR and NMR in the Identification of an Unknown Substance

ERIC Educational Resources Information Center

Glagovich, Neil M.; Shine, Timothy D.

2005-01-01

A laboratory experiment that emphasizes the interpretation of both infrared (IR) and nuclear magnetic resonance (NMR) spectra in the elucidation of the structure of an unknown compound was developed. The method helps students determine [to the first power]H- and [to the thirteenth power]C-NMR spectra from the structures of compounds and to…

Computational NMR, IR/RAMAN calculations in sodium pravastatin: Investigation of the Self-Assembled Nanostructure of Pravastatin-LDH (Layered Double Hydroxides) Systems

NASA Astrophysics Data System (ADS)

Petersen, Philippe; Cunha, Vanessa; Gonçalves, Marcos; Petrilli, Helena; Constantino, Vera; Instituto de Física, Departamento de Física de Materiais e Mecânica Team; Instituto de Química, Departamento de Química Fundamental Team

2013-03-01

Layered double hydroxides (LDH) can be used as nanocontainers for immobilization of Pravastatin, in order to obtain suitable drug carriers. The material's structure and spectroscopic properties were analyzed by NMR, IR/RAMAN and supported by theoretical calculations. Density Functional Theory (DFT) calculations were performed using the Gaussian03 package. The geometry optimizations were performed considering the single crystal X-ray diffraction data of tert-octylamonium salt of Pravastatin. Tetramethylsilane (TMS), obtained with the same basis set, was used as reference for calculating the chemical shift of 13C. A scaling factor was used to compare theoretical and experimental harmonic vibrational frequencies. Through the NMR and IR/RAMAN spectra, we were able to make precise assignments of the NMR and IR/RAMAN of Sodium Pravastatin. We acknowledge support from CAPES, INEO and CNPQ.

Structural characterization, surface characteristics and non covalent interactions of a heterocyclic Schiff base: Evaluation of antioxidant potential by UV-visible spectroscopy and DFT

NASA Astrophysics Data System (ADS)

Chithiraikumar, S.; Gandhimathi, S.; Neelakantan, M. A.

2017-06-01

A heterocyclic Schiff base, (E)-4-(1-((pyridin-2-ylmethyl)imino)ethyl)benzene-1,3-diol (L) was synthesized and isolated as single crystals. Its structure was characterized by FT-IR, UV, 1H and 13C NMR, and further confirmed by X-ray crystallography. Qualitatively and quantitatively the various interactions in the crystal structure of L has been analyzed by Hirshfeld surfaces and 2D fingerprint plots. Non covalent interactions have been studied by electron localization function (ELF) and mapped with reduced density gradient (RDG) analysis. The molecular structure was studied computationally by DFT-B3LYP/6-311G(d,p) calculations. HOMO-LUMO energy levels, chemical reactivity descriptors and thermodynamic parameters have been investigated at the same level of theory. The antioxidant potential of L was evaluated experimentally by measuring DPPH free radical scavenging effect using UV-visible spectroscopy and theoretically by DFT. Theoretical parameters, such as bond dissociation enthalpy (BDE) and spin density calculated suggests that antioxidant potential of L is due to H atom abstraction from the sbnd OH group.

UV-visible-DAD and 1H-NMR spectroscopy data fusion for studying the photodegradation process of azo-dyes using MCR-ALS.

PubMed

Fernández, Cristina; Pilar Callao, M; Larrechi, M Soledad

2013-12-15

The photodegradation process of three azo-dyes - Acid Orange 61, Acid Red 97 and Acid Brown 425 - was monitored simultaneously by ultraviolet-visible spectroscopy with diode array detector (UV-vis-DAD) and (1)H-nuclear magnetic resonance ((1)H-NMR). Multivariate curve resolution-alternating least squares (MCR-ALS) was applied to obtain the concentration and spectral profile of the chemical compounds involved in the process. The analysis of the H-NMR data suggests there are more intermediate compounds than those obtained with the UV-vis-DAD data. The fusion of UV-vis-DAD and the (1)H-NMR signal before the multivariate analysis provides better results than when only one of the two detector signals was used. It was concluded that three degradation products were present in the medium when the three azo-dyes had practically degraded. This study is the first application of UV-vis-DAD and (1)H-NMR spectroscopy data fusion in this field and illustrates its potential as a quick method for evaluating the evolution of the azo-dye photodegradation process. © 2013 Elsevier B.V. All rights reserved.

EVIDENCE FOR A WIDE RANGE OF ULTRAVIOLET OBSCURATION IN z {approx} 2 DUSTY GALAXIES FROM THE GOODS-HERSCHEL SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penner, Kyle; Dickinson, Mark; Dey, Arjun

Dusty galaxies at z {approx} 2 span a wide range of relative brightness between rest-frame mid-infrared (8 {mu}m) and ultraviolet wavelengths. We attempt to determine the physical mechanism responsible for this diversity. Dust-obscured galaxies (DOGs), which have rest-frame mid-IR to UV flux density ratios {approx}> 1000, might be abnormally bright in the mid-IR, perhaps due to prominent emission from active galactic nuclei and/or polycyclic aromatic hydrocarbons, or abnormally faint in the UV. We use far-infrared data from the GOODS-Herschel survey to show that most DOGs with 10{sup 12} L {sub Sun} {approx}< L {sub IR} {approx}< 10{sup 13} L {submore » Sun} are not abnormally bright in the mid-IR when compared to other dusty galaxies with similar IR (8-1000 {mu}m) luminosities. We observe a relation between the median IR to UV luminosity ratios and the median UV continuum power-law indices for these galaxies, and we find that only 24% have specific star formation rates that indicate the dominance of compact star-forming regions. This circumstantial evidence supports the idea that the UV- and IR-emitting regions in these galaxies are spatially coincident, which implies a connection between the abnormal UV faintness of DOGs and dust obscuration. We conclude that the range in rest-frame mid-IR to UV flux density ratios spanned by dusty galaxies at z {approx} 2 is due to differing amounts of UV obscuration. Of galaxies with these IR luminosities, DOGs are the most obscured. We attribute differences in UV obscuration to either (1) differences in the degree of alignment between the spatial distributions of dust and massive stars or (2) differences in the total dust content.« less

Photodissociation Spectroscopy of Cold Protonated Synephrine: Surprising Differences between IR-UV Hole-Burning and IR Photodissociation Spectroscopy of the O-H and N-H Modes.

PubMed

Nieuwjaer, N; Desfrançois, C; Lecomte, F; Manil, B; Soorkia, S; Broquier, M; Grégoire, G

2018-04-19

We report the UV and IR photofragmentation spectroscopies of protonated synephrine in a cryogenically cooled Paul trap. Single (UV or IR) and double (UV-UV and IR-UV) resonance spectroscopies have been performed and compared to quantum chemistry calculations, allowing the assignment of the lowest-energy conformer with two rotamers depending on the orientation of the phenol hydroxyl (OH) group. The IR-UV hole burning spectrum exhibits the four expected vibrational modes in the 3 μm region, i.e., the phenol OH, C β -OH, and two NH 2 + stretches. The striking difference is that, among these modes, only the free phenol OH mode is active through IRPD. The protonated amino group acts as a proton donor in the internal hydrogen bond and displays large frequency shifts upon isomerization expected during the multiphoton absorption process, leading to the so-called IRMPD transparency. More interestingly, while the C β -OH is a proton acceptor group with moderate frequency shift for the different conformations, this mode is still inactive through IRPD.

On-line high-performance liquid chromatography-ultraviolet-nuclear magnetic resonance method of the markers of nerve agents for verification of the Chemical Weapons Convention.

PubMed

Mazumder, Avik; Gupta, Hemendra K; Garg, Prabhat; Jain, Rajeev; Dubey, Devendra K

2009-07-03

This paper details an on-flow liquid chromatography-ultraviolet-nuclear magnetic resonance (LC-UV-NMR) method for the retrospective detection and identification of alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs), the markers of the toxic nerve agents for verification of the Chemical Weapons Convention (CWC). Initially, the LC-UV-NMR parameters were optimized for benzyl derivatives of the APAs and AAPAs. The optimized parameters include stationary phase C(18), mobile phase methanol:water 78:22 (v/v), UV detection at 268nm and (1)H NMR acquisition conditions. The protocol described herein allowed the detection of analytes through acquisition of high quality NMR spectra from the aqueous solution of the APAs and AAPAs with high concentrations of interfering background chemicals which have been removed by preceding sample preparation. The reported standard deviation for the quantification is related to the UV detector which showed relative standard deviations (RSDs) for quantification within +/-1.1%, while lower limit of detection upto 16mug (in mug absolute) for the NMR detector. Finally the developed LC-UV-NMR method was applied to identify the APAs and AAPAs in real water samples, consequent to solid phase extraction and derivatization. The method is fast (total experiment time approximately 2h), sensitive, rugged and efficient.

Quantification of taurine in energy drinks using ¹H NMR.

PubMed

Hohmann, Monika; Felbinger, Christine; Christoph, Norbert; Wachter, Helmut; Wiest, Johannes; Holzgrabe, Ulrike

2014-05-01

The consumption of so called energy drinks is increasing, especially among adolescents. These beverages commonly contain considerable amounts of the amino sulfonic acid taurine, which is related to a magnitude of various physiological effects. The customary method to control the legal limit of taurine in energy drinks is LC-UV/vis with postcolumn derivatization using ninhydrin. In this paper we describe the quantification of taurine in energy drinks by (1)H NMR as an alternative to existing methods of quantification. Variation of pH values revealed the separation of a distinct taurine signal in (1)H NMR spectra, which was applied for integration and quantification. Quantification was performed using external calibration (R(2)>0.9999; linearity verified by Mandel's fitting test with a 95% confidence level) and PULCON. Taurine concentrations in 20 different energy drinks were analyzed by both using (1)H NMR and LC-UV/vis. The deviation between (1)H NMR and LC-UV/vis results was always below the expanded measurement uncertainty of 12.2% for the LC-UV/vis method (95% confidence level) and at worst 10.4%. Due to the high accordance to LC-UV/vis data and adequate recovery rates (ranging between 97.1% and 108.2%), (1)H NMR measurement presents a suitable method to quantify taurine in energy drinks. Copyright © 2013 Elsevier B.V. All rights reserved.

Structural, antimicrobial and computational characterization of 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea.

PubMed

Atiş, Murat; Karipcin, Fatma; Sarıboğa, Bahtiyar; Taş, Murat; Çelik, Hasan

2012-12-01

A new thiourea derivative, 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea (bcht) has been synthesized from the reaction of 2-amino-4-chlorophenol with benzoyl isothiocyanate. The title compound has been characterized by elemental analyses, FT-IR, (13)C, (1)H NMR spectroscopy and the single crystal X-ray diffraction analysis. The structure of bcht derived from X-ray diffraction of a single crystal has been presented. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The complete assignments of all vibrational modes were performed on the basis of the total energy distributions (TED). Isotropic chemical shifts ((13)C NMR and (1)H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. Theoretical calculations of bond parameters, harmonic vibration frequencies and nuclear magnetic resonance are in good agreement with experimental results. The UV absorption spectra of the compound that dissolved in ACN and MeOH were recorded. Bcht was also screened for antimicrobial activity against pathogenic bacteria and fungi. Copyright © 2012 Elsevier B.V. All rights reserved.

NBO, conformational, NLO, HOMO-LUMO, NMR and electronic spectral study on 1-phenyl-1-propanol by quantum computational methods

NASA Astrophysics Data System (ADS)

Xavier, S.; Periandy, S.; Ramalingam, S.

2015-02-01

In this study, FT-IR, FT-Raman, NMR and UV spectra of 1-phenyl-1-propanol, an intermediate of anti-depressant drug fluoxetine, has been investigated. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been found in good agreement with the corresponding experimental data. 1H and 13C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies are performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The local reactivity of the molecule has been studied using the Fukui function. NLO properties related to polarizability and hyperpolarizability are also discussed.

A new Schiff base compound N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone): synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, 1H NMR and 13C NMR spectra.

PubMed

Saheb, Vahid; Sheikhshoaie, Iran

2011-10-15

The Schiff base compound, N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone) (NDHA) is synthesized through the condensation of 2-hydroxylacetophenone and 2,2-dimethyl 1,3-amino propane in methanol at ambient temperature. The yellow crystalline precipitate is used for X-ray single-crystal determination and measuring Fourier transform infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP, PBEPBE and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the FTIR, (1)H NMR and (13)C NMR spectra of the compound. Time-dependent density functional theory (TDDFT) method is used to calculate the UV-visible spectrum of NDHA. Vibrational frequencies are determined experimentally and compared with those obtained theoretically. Vibrational assignments and analysis of the fundamental modes of the compound are also performed. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR and (13)C NMR chemical shifts calculated by all DFT methods are consistent with the experimental data. However, the NMR shielding tensors computed at the B3LYP/6-31+G(d,p) level of theory are in better agreement with experimental (1)H NMR and (13)C NMR spectra. The electronic absorption spectrum calculated at the B3LYP/6-31+G(d,p) level by using TD-DFT method is in accordance with the observed UV-visible spectrum of NDHA. In addition, some quantum descriptors of the molecule are calculated and conformational analysis is performed and the results were compared with the crystallographic data. Copyright © 2011 Elsevier B.V. All rights reserved.

Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

NASA Astrophysics Data System (ADS)

Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

2013-02-01

New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

Synthesis, spectroscopic characterization, DFT study and antimicrobial activity of novel alkylaminopyrazole derivatives

NASA Astrophysics Data System (ADS)

Zalaru, Christina; Dumitrascu, Florea; Draghici, Constantin; Tarcomnicu, Isabela; Tatia, Rodica; Moldovan, Lucia; Chifiriuc, Mariana-Carmen; Lazar, Veronica; Marinescu, Maria; Nitulescu, Mihai George; Ferbinteanu, Marilena

2018-03-01

A new series of substituted N,N-bis-[(1H-pyrazol-1-yl)methyl]-aminohexadecane Mannich bases were synthesized, characterized by IR, 1H NMR 13C NMR, UV-Vis, MS and elemental analysis, and tested for their biological activity. All the synthesized compounds were tested for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using erythromycin and clotrimazole as standards. Most of the synthesized compounds demonstrated very good activity at minimum inhibitory concentrations (MICs). Compound 3b with an halogen atom into the pharmacophore structure exhibited the most significant activity against Bacillus subtilis (MIC = 0.007 μgmLL-1) versus erythromycin as standard. In vitro cytotoxicity of the new compounds was studied using MTT assay. The analysis of the test cells showed that the newly synthesized alkylaminopyrazoles derivatives were biocompatible until a concentration of 5 μgmL-1; two compounds presented a high degree of biocompatibility on the studied concentration range.

Synthesis of 21,23-selenium- and tellurium-substituted 5-porphomethenes, 5,10-porphodimethenes, 5,15-porphodimethenes, and porphotrimethenes and their interactions with mercury.

PubMed

Ahmad, Sohail; Yadav, Kumar Karitkey; Bhattacharya, Soumee; Chauhan, Prashant; Chauhan, S M S

2015-04-17

The 3+1 condensation of symmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols in the presence of BF3-etheratre or BF3-methanol followed by oxidation with DDQ gave 5,10-porphodimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave 5-porphomethenes. In addition, the reaction of unsymmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the corresponding porphotrimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the 5,15-porphodimethenes. The structures of different products were characterized by IR, (1)H and (13)C NMR, (1)H-(1)H COSY, CHN analysis, and mass spectrometry. The binding of mercury with the calix[4]phyrins mentioned above had been observed in the decreasing order of porphodimethenes > porphomethenes > porphotrimethenes by UV-vis and (1)H NMR spectroscopy.

Synthesis, characterization, antibacterial activities and carbonic anhydrase enzyme inhibitor effects of new arylsulfonylhydrazone and their Ni(II), Co(II) complexes

NASA Astrophysics Data System (ADS)

Özdemir, Ümmühan Özmen; Arslan, Fatma; Hamurcu, Fatma

2010-01-01

Ethane sulfonic acide hydrazide ( esh: CH 3CH 2SO 2NHNH 2) derivatives as 5-methylsalicyl-aldehydeethanesulfonylhydrazone ( 5msalesh), 5-methyl-2-hydroxyacetophenoneethane sulfonylhydrazone ( 5mafesh) and their Ni(II), Co(II) complexes have been synthesized for the first time. The structure of these compounds has been investigated by elemental analysis, FT-IR, 1H NMR, 13C NMR, LC/MS, UV-vis spectrophotometric method, magnetic susceptibility, thermal studies and conductivity measurements. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus, Bacillus subtilis, Bacillus magaterium and Gram negative bacteria; Salmonella enteritidis, Escherichia coli by using the microdilution broth method. The biological activity screening showed that ligands have more activity than complexes against the tested bacteria. The inhibition activities of these compounds on carbonic anhydrase II (CA II) have been investigated by comparing IC 50 and Ki values and it has been found that 5msalesh and its complexes have more enzyme inhibition efficiency than other compounds.

Autonomous driving in NMR.

PubMed

Perez, Manuel

2017-01-01

The automatic analysis of NMR data has been a much-desired endeavour for the last six decades, as it is the case with any other analytical technique. This need for automation has only grown as advances in hardware; pulse sequences and automation have opened new research areas to NMR and increased the throughput of data. Full automatic analysis is a worthy, albeit hard, challenge, but in a world of artificial intelligence, instant communication and big data, it seems that this particular fight is happening with only one technique at a time (let this be NMR, MS, IR, UV or any other), when the reality of most laboratories is that there are several types of analytical instrumentation present. Data aggregation, verification and elucidation by using complementary techniques (e.g. MS and NMR) is a desirable outcome to pursue, although a time-consuming one if performed manually; hence, the use of automation to perform the heavy lifting for users is required to make the approach attractive for scientists. Many of the decisions and workflows that could be implemented under automation will depend on the two-way communication with databases that understand analytical data, because it is desirable not only to query these databases but also to grow them in as much of an automatic manner as possible. How these databases are designed, set up and the data inside classified will determine what workflows can be implemented. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Modelling a man-portable air-defence (MANPAD) system with a rosette scan two-colour infrared (IR) and ultraviolet (UV) seeker

NASA Astrophysics Data System (ADS)

Kumar, Devinder; Smith, Leon; Richardson, Mark A.; Ayling, Richard; Barlow, Nick

2014-10-01

The Ultraviolet (UV) band of the electromagnetic (EM) spectrum has the potential to be used as the host medium for the operation of guided weapons. Unlike in the Infrared (IR), a target propelled by an air breathing jet engine produces no detectable radiation in the UV band, and is opaque to the background UV produced by the Sun. Successful engineering of spectral airborne IR countermeasures (CM) against existing two colour IR seekers has encouraged missile counter-countermeasure (CCM) designers to utilise the silhouette signature of an aircraft in the UV as a means of distinguishing between a true target and a flare CM. In this paper we describe the modelling process of a dual band IR and UV rosette scan seeker using CounterSim, a missile engagement and countermeasure simulation software package developed by Chemring Countermeasures Ltd. Results are shown from various simulated engagements of the dual band MANPAD with a C-130 Hercules modelled by Chemring Countermeasures. These results have been used to estimate the aircrafts' vulnerability to this MANPAD threat. A discussion on possible future optical countermeasures against dual band IR-UV seekers is given in conclusion to the simulation results.

LC-UV-solid-phase extraction-NMR-MS combined with a cryogenic flow probe and its application to the identification of compounds present in Greek oregano.

PubMed

Exarchou, Vassiliki; Godejohann, Markus; van Beek, Teris A; Gerothanassis, Ioannis P; Vervoort, Jacques

2003-11-15

Structure elucidation of natural products usually relies on a combination of NMR spectroscopy with mass spectrometry whereby NMR trails MS in terms of the minimum sample amount required. In the present study, the usefulness of on-line solid-phase extraction (SPE) in LC-NMR for peak storage after the LC separation prior to NMR analysis is demonstrated. The SPE unit allows the use of normal protonated solvents for the LC separation and fully deuterated solvents for flushing the trapped compounds to the NMR probe. Thus, solvent suppression is no longer necessary. Multiple trapping of the same analyte from repeated LC injections was utilized to solve the problem of low concentration and to obtain 2D heteronuclear NMR spectra. In addition, a combination of the SPE unit with a recently developed cryoflow NMR probe and an MS was evaluated. This on-line LC-UV-SPE-NMR-MS system was used for the automated analysis of a Greek oregano extract. Combining the data provided by the UV, MS, and NMR spectra, the flavonoids taxifolin, aromadendrin, eriodictyol, naringenin, and apigenin, the phenolic acid rosmarinic acid, and the monoterpene carvacrol were identified. This automated technique is very useful for natural product analysis, and the large sensitivity improvement leads to significantly reduced NMR acquisition times.

Self-assembly of chiral molecular polygons.

PubMed

Jiang, Hua; Lin, Wenbin

2003-07-09

Treatment of 2,2'-diacetyl-1,1'-binaphthyl-6,6'-bis(ethyne), L-H2, with 1 equiv of trans-Pt(PEt3)2Cl2 led to a mixture of different sizes of chiral metallocycles [trans-(PEt3)2Pt(L)]n (n = 3-8, 1-6). Each of the chiral molecular polygons 1-6 was purified by silica gel column chromatography and characterized by 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, MS, IR, UV-vis, and circular dichroism spectroscopies, and microanalysis. The presence of tunable cavities (1.4-4.3 nm) and chiral functionalities in these molecular polygons promises to make them excellent receptors for a variety of guests.

Intramolecular charge transfer effects on 4-hydroxy-3-methoxybenzaldehyde

NASA Astrophysics Data System (ADS)

Rajendiran, N.; Balasubramanian, T.

2008-03-01

The absorption and fluorescence spectral characteristics of 4-hydroxy-3-methoxybenzaldehyde (HMB) have been studied in different solvents, pH and β-cyclodextrin (β-CD) and compared with 4-hydroxy-3,5-dimethoxybenzaldehyde (HDMB). The inclusion complex of HMB with β-CD is analysed by UV-vis, fluorimetry, FT-IR, 1H NMR, SEM and AM1 methods. In HMB, the normal emission (B band) is originates from a locally excited state and the longer emission (A band) is due to intramolecular charge transfer state (ICT). The OH group of HMB is present in the interior part of the β-CD cavity and aldehyde group present in the upper part of the β-CD cavity.

Synthesis, structural, thermal and optical studies of 1-ethyl-2,6-dimethyl-4-hydroxy pyridinium halides.

PubMed

Dhanuskodi, S; Manivannan, S; Kirschbaum, K

2006-05-15

1-Ethyl-2,6-dimethyl-4-hydroxy pyridinium chloride dihydrate and bromide dihydrate salts have been synthesized and their single crystals were grown by the slow evaporation of aqueous solution at 30 degrees C. The grown crystals were characterized by elemental analysis, FT-NMR and FT-IR techniques to confirm the formation of the expected compound. Optical transmittance window in aqueous solution was found to be 275-1100 nm by UV-vis-NIR technique. Thermogravimetric and differential thermal analyses reveal thermal stability and the presence of two water molecules in the crystal lattices. The crystal structure of chloride salt was also determined by X-ray diffraction method.

Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

PubMed Central

Wang, Kun; Xu, Feng; Sun, Runcang

2010-01-01

Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules. PMID:21152286

New Cerebroside and Nucleoside Derivatives from a Red Sea Strain of the Marine Cyanobacterium Moorea producens.

PubMed

Youssef, Diaa T A; Ibrahim, Sabrin R M; Shaala, Lamiaa A; Mohamed, Gamal A; Banjar, Zainy M

2016-03-09

In the course of our ongoing efforts to identify marine-derived bioactive compounds, the marine cyanobacterium Moorea producens was investigated. The organic extract of the Red Sea cyanobacterium afforded one new cerebroside, mooreaside A (1), two new nucleoside derivatives, 3-acetyl-2'-deoxyuridine (2) and 3-phenylethyl-2'-deoxyuridine (3), along with the previously reported compounds thymidine (4) and 2,3-dihydroxypropyl heptacosanoate (5). The structures of the compounds were determined by different spectroscopic studies (UV, IR, 1D, 2D NMR, and HRESIMS), as well as comparison with the literature data. Compounds 1-5 showed variable cytotoxic activity against three cancer cell lines.

Synthesis and characterization of copper complexes of Schiff base derived from isatin and salicylic hydrazide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lekshmy, R. K., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com; Thara, G. S., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com

A series of novel metal complexes of Schiff base have been prepared by the interaction of Cu(II) with isatin salicylic hydrazide. All the new compounds were characterized by elemental analysis, conductance measurement, magnetic moment determination, IR, UV, NMR, Mass and EPR spectral studies, thermal studies and microbial activities. The results indicate that the ligand acts as a tridentate chelating ligand coordinating through nitrogen and oxygen atoms. The ligand and complexes show inactive against Escherichia coli and active against Staphylococcus aureus and B.substilis. By analyzing the results of spectral, thermal and elemental analysis square planar geometry is proposed for all themore » complexes.« less

Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

PubMed

Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

2014-01-01

Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

New benzophenone and quercetin galloyl glycosides from Psidium guajava L.

PubMed

Matsuzaki, Keiichi; Ishii, Rie; Kobiyama, Kaori; Kitanaka, Susumu

2010-07-01

New benzophenone and flavonol galloyl glycosides were isolated from an 80% MeOH extract of Psidium guajava L. (Myrtaceae) together with five known quercetin glycosides. The structures of the novel glycosides were elucidated to be 2,4,6-trihydroxybenzophenone 4-O-(6''-O-galloyl)-beta-D: -glucopyranoside (1, guavinoside A), 2,4,6-trihydroxy-3,5-dimethylbenzophenone 4-O-(6''-O-galloyl)-beta-D: -glucopyranoside (2, guavinoside B), and quercetin 3-O-(5''-O-galloyl)-alpha-L: -arabinofuranoside (3, guavinoside C) by NMR, MS, UV, and IR spectroscopies. Isolated phenolic glycosides showed significant inhibitory activities against histamine release from rat peritoneal mast cells, and nitric oxide production from a murine macrophage-like cell line, RAW 264.7.

Computational and spectroscopic data correlation study of N,N'-bisarylmalonamides (Part II).

PubMed

Arsovski, Violeta M; Božić, Bojan Đ; Mirković, Jelena M; Vitnik, Vesna D; Vitnik, Željko J; Petrović, Slobodan D; Ušćumlić, Gordana S; Mijin, Dušan Ž

2015-09-01

To complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data ((1)H and (13)C NMR chemical shifts as well as FT-IR absorption frequency) applied to N,N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6-311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained. The overall results presented in this paper show that N,N'-bisarylmalonamides are prominent candidates for model molecules.

Transition Metal Complexes of Quinolino[3,2-b]benzodiazepine and Quinolino[3,2-b]benzoxazepine: Synthesis, Characterization, and Antimicrobial Studies

PubMed Central

Basavaraju, B.; Bhojya Naik, Halehatty S.; Prabhakara, Mustur C.

2007-01-01

The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand. PMID:18273383

Dye Foils With Increased Durability For Passive Q-Switching In A 1064 Nm Laser.

NASA Astrophysics Data System (ADS)

Mierczyk, Z.; Kwasny, M.; Czeszko, J.

1987-10-01

The results of spectral (IR, UV-VIS, H NMR) , gel permeation chromatography and differential thermal analysis investigations of structures of dye foils consisting of bis-(4-dimethyl-amino-dithio-benzil)-nickel dye suspended in polymethylmethacrylate matrix, to be used for passive Q-switching in a 1064 nm laser, are reported. Results of experimental measurements and of numerical calculations of thermal and generating properties, and of the endurance of passive foil type Q-switches in the resona-tor of YAG:Nd3+ laser are also presented. Optimization of polymerization conditions has enabled the production of dye foils with high thermal and photochemical resistance, which give stable operation of a giant pulsed laser.

The spectroscopy of singlets and triplets excites electronic states, spatial and electronic structure of hydrocarbons and quantum classifications in chemmotology

NASA Astrophysics Data System (ADS)

Obukhov, A. E.

2017-01-01

In this work we demonstrate the physical foundations of the spectroscopy of the grounds states: E- and X-ray, (RR) Raman scattering the NMR 1H and 13C and IR-, EPR- absorption and the singlets and triplets electronic excited states in the multinuclear hydrocarbons in chemmotology. The parameters of UV-absorption, RR-Raman scattering of light, the fluorescence and the phosphorescence and day-lasers at the pumping laser and lamp, OLEDs and OTETs- are measurements. The spectral-energy properties are briefly studied. The quantum-chemical LCAO-MO SCF expanded-CI PPP/S and INDO/S methods in the electronic and spatial structure hidrocarbons are considered.

Synthesis, characterization, spectroscopic studies and antimicrobial activity of three new Schiff bases derived from Heterocyclic moiety

NASA Astrophysics Data System (ADS)

Mesbah, Mounira; Douadi, Tahar; Sahli, Farida; Issaadi, Saifi; Boukazoula, Soraya; Chafaa, Salah

2018-01-01

Three new Schiff-bases compounds (I-III) were synthesized by a condensation reaction in 1:2 M ratios of 4,4‧-diaminodiphenyl sulfide and pyrrol/thiophene/furan-2-carboxaldehyde in ethanol. The structural determinations of the Schiff-bases were identified with the help of elemental analysis then confirmed by UV-Vis, FT-IR and 1H NMR. The products were obtained in excellent yields. On the other hand, the in vitro antibacterial and antifungal activities of the synthesized compounds were investigated using disc diffusion method. Schiff bases synthesized individually exhibited varying degrees of inhibitory effects on the growth of the tested microbial species.

A novel tridentate Schiff base dioxo-molybdenum(VI) complex: synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, ¹H NMR and ¹³C NMR spectra.

PubMed

Saheb, Vahid; Sheikhshoaie, Iran; Stoeckli-Evans, Helen

2012-09-01

A new dioxo-molybdenum(VI) complex [MoO(2)(L)(H(2)O)] has been synthesized, using 5-methoxy 2-[(2-hydroxypropylimino)methyl]phenol as tridentate ONO donor Schiff base ligand (H(2)L) and MoO(2)(acac)(2). The yellow crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the UV-visible, FTIR, (1)H NMR and (13)C NMR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TDDFT) method is used to calculate the electronic transitions of the complex. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR shielding tensors computed at the B3LYP/DGDZVP level of theory is in agreement with experimental (1)H NMR spectra. However, the (13)C NMR shielding tensors computed at the B3LYP level, employing a combined basis set of DGDZVP for Mo and 6-31+G(2df,p) for other atoms, are in better agreement with experimental (13)C NMR spectra. The electronic transitions calculated at the B3LYP/DGDZVP level by using TD-DFT method is in accordance with the observed UV-visible spectrum of the compound. Copyright © 2012 Elsevier B.V. All rights reserved.

Metal based biologically active compounds: Design, synthesis, DNA binding and antidiabetic activity of 6-methyl-3-formyl chromone derived hydrazones and their metal (II) complexes.

PubMed

Philip, Jessica Elizabeth; Shahid, Muhammad; Prathapachandra Kurup, M R; Velayudhan, Mohanan Puzhavoorparambil

2017-10-01

Two chromone hydrazone ligands HL 1 and HL 2 were synthesized and characterized by elemental analyses, IR, 1 H NMR & 13 C NMR, electronic absorption and mass spectra. The reactions of the chromone hydrazones with transition metals such as Ni, Cu, and Zn (II) salts of acetate afforded mononuclear metal complexes. Characterization and structure elucidation of the prepared chromone hydrazone metal (II) complexes were done by elemental, IR, electronic, EPR spectra and thermo gravimetric analyses as well as conductivity and magnetic susceptibility measurements. The spectroscopic data showed that the ligand acts as a mono basic bidentate with coordination sites are azomethine nitrogen and hydrazonic oxygen, and they exhibited distorted geometry. The biological studies involved antidiabetic activity i.e. enzyme inhibition of α-amylase and α-glucosidase, Calf Thymus - DNA (CT-DNA) interaction and molecular docking. Potential capacity of synthesized compounds to inhibit the α-amylase and α-glucosidase activity was assayed whereas DNA interaction studies were carried out with the help UV-Vis absorption titration and viscosity method. The docking studies of chromone hydrazones show that they are minor groove binders. Complexes were found to be good DNA - intercalates. Chromone hydrazones and its transition metal complexes have shown comparable antidiabetic activity with a standard drug acarbose. Copyright © 2017 Elsevier B.V. All rights reserved.

The Use and Evaluation of Scaffolding, Student Centered-Learning, Behaviorism, and Constructivism to Teach Nuclear Magnetic Resonance and IR Spectroscopy in a Two-Semester Organic Chemistry Course

ERIC Educational Resources Information Center

Livengood, Kimberly; Lewallen, Denver W.; Leatherman, Jennifer; Maxwell, Janet L.

2012-01-01

Since 2002, infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectrometry have been introduced at the beginning of the first-semester organic chemistry lab course at this university. Starting in 2008, each individual student was given 20 unique homework problems that consisted of multiple-choice [superscript 1]H NMR and IR problems…

Spectroscopic, electrochemical and photovoltaic properties of Pt(ii) and Pd(ii) complexes of a chelating 1,10-phenanthroline appended perylene diimide.

PubMed

Işık Büyükekşi, Sebile; Şengül, Abdurrahman; Erdönmez, Seda; Altındal, Ahmet; Orman, Efe Baturhan; Özkaya, Ali Rıza

2018-02-20

In this study, a bis-chelating bridging perylene diimide ditopic ligand, namely N,N'-di(1,10-phenanthroline)-1,6,7,12-tetrakis-(4-methoxyphenoxy)perylene tetracarboxylic acid diimide (1), was synthesized and characterized. Further reactions of 1 with d 8 metal ions such as Pt(ii) and Pd(ii) having preferential square-planar geometry afforded the novel triads [(Cl 2 )M(ii)-(1)-M(ii)(Cl 2 )] where M(ii) = Pt(ii) (2), and Pd(ii) (3), respectively. The isolated triads and the key precursor were fully characterized by FT-IR, 1D-NMR ( 1 H NMR and 13 C DEPT NMR), 2D-NMR ( 1 H- 1 H COSY, 1 H- 13 C HSQC, 1 H- 13 C HMBC), MALDI-TOF mass and UV/Vis spectroscopy. The electrochemical properties of 1, 2 and 3 were investigated by cyclic voltammetry as well as in situ spectroelectrochemistry and also in situ electrocolorimetric measurements. These compounds were shown to exhibit net colour changes suitable for electrochromic applications. The compounds exhibited remarkably narrow HOMO-LUMO gaps, leading to their ease of reduction at low negative potentials. More importantly, dye-sensitized solar cells (DSSCs) were also fabricated using 1-3 to clarify the potential use of these complexes as a sensitizer. Analysis of the experimental data indicated that 2 has good potential as a sensitizer material for DSSCs.

Spectroscopic studies, antimicrobial activities and crystal structures of N-(2-hydroxy-3-methoxybenzalidene)1-aminonaphthalene

NASA Astrophysics Data System (ADS)

Ünver, Hüseyin; Yıldız, Mustafa; Dülger, Başaran; Özgen, Özen; Kendi, Engin; Durlu, Tahsin Nuri

2005-03-01

Schiff base N-(2-hydroxy-3-methoxybenzalidene)1-aminonaphthalene has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with 1-aminonaphthalene. The compound were characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR and UV-visible techniques. The UV-visible spectra of the Schiff base were studied in polar and nonpolar solvents in acidic and basic media. The structure of the compound has been examined cyrstallographically. There are two independent molecules in the asymmetric unit. It crystallizes in the monoclinic space group P21/c, with unit cell parameters: a=14, 602(2), b=5,800(1), c=16, 899(1) Å, V=1394.4(2) Å 3, Dx=1.321 g cm -3 and Z=4. The crystal structure was solved by direct methods and refined by full-matrix least squares to a find R=0.041 of for 1179 observed reflections. The title compound's antimicrobial activities also have been studied. The antimicrobial activities of the ligand has been screened in vitro against the organisms Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae UC57, Micrococcus luteus La 2971, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis CCM 2067, Bacillus cereus ATCC 7064 and Listeria monocytogenes ATCC 15313, the yeast cultures Candida albicans ATCC 10231, Kluyveromyces fragilis NRRL 2415, Rhodotorula rubra DSM 70403, Debaryomyces hansenii DSM 70238 and Hanseniaspora guilliermondii DSM 3432.

Synthesis, spectral characterization, thermal and photoluminescence properties of Zn(II) and Cd(II)-azido/thiocyanato complexes with thiazolylazo dye and 1,2-bis(diphenylphoshino)ethane.

PubMed

Yamgar, B A; Sawant, V A; Bharate, B G; Chavan, S S

2011-01-01

A series of complexes of the type [M(L)(dppe)X2]; where M=Zn(II) or Cd(II); L=4-(2'-thiazolylazo)chlorobenzene (L1), 4-(2'-thiazolylazo)bromobenzene (L2) and 4-(2'-thiazolylazo) iodobenzene (L3); dppe=1,2-bis(diphenylphosphino)ethane; X=N3- or NCS- have been prepared and characterized on the basis of their microanalysis, molar conductance, thermal, IR, UV-vis and 1H NMR spectral studies. IR spectra show that the ligand L is coordinated to the metal atom in bidentate manner via azo nitrogen and thiazole nitrogen. An octahedral structure is proposed for all the complexes. The thermal behavior of the complexes revealed that the thiocyanato complexes are thermally more stable than the azido complexes. All the complexes exhibit blue-green emission with high quantum yield as the result of the fluorescence from the intraligand emission excited state. Copyright © 2010 Elsevier B.V. All rights reserved.

Synthesis, spectral, thermal and antimicrobial studies of transition metal complexes of 14-membered tetraaza[N4] macrocyclic ligand

NASA Astrophysics Data System (ADS)

Shankarwar, Sunil G.; Nagolkar, Bhagwat B.; Shelke, Vinod A.; Chondhekar, Trimbak K.

2015-06-01

A series of metal complexes of Mn(II), Co(II), Ni(II), Cu(II), have been synthesized with newly synthesized biologically active macrocyclic ligand. The ligand was synthesized by condensation of β-diketone 1-(4-chlorophenyl)-3-(2-hydroxyphenyl)propane-1,3-dione and o-phenylene diamine. All the complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, 1H-NMR, UV-Vis spectroscopy and mass spectroscopy. From the analytical data, stoichiometry of the complexes was found to be 1:2 (metal:ligand). Thermal behavior (TG/DTA) and kinetic parameters suggest more ordered activated state in complex formation. All the complexes are of high spin type and six coordinated. On the basis of IR, electronic spectral studies and magnetic behavior, an octahedral geometry has been assigned to these complexes. The antibacterial and antifungal activities of the ligand and its metal complexes, has been screened in vitro against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma respectively.

Spectroscopic and theoretical investigations of alkali metal linoleates and oleinates

NASA Astrophysics Data System (ADS)

Świsłocka, Renata; Regulska, Ewa; Jarońko, Paweł; Lewandowski, Włodzimierz

2017-11-01

The influence of lithium, sodium, potassium, rubidium and cesium on the electronic system of the linoleic (cis-9,cis-12-octadecadienoic) and oleic (cis-9-octadecenoic) acids was investigated. The complementary analytical methods: vibrational (IR, Raman) and electronic (UV) molecular absorption spectroscopy as well as DFT quantum mechanical calculations (charge distribution, angles between bonds, bond lengths, theoretical IR and NMR spectra) were carried out. The regular shifts of bands connected with carboxylate anion in the spectra of studied salts were observed. Some bonds and angles reduced or elongated in the series: acid→Li→Na→K linoleates/oleinates. The highest changes were noted for bond lengths and angles concerning COO- ion. The electronic charge distribution in studied molecules was also discussed. Total atomic charges of carboxylate anion decrease as a result of the replacement of hydrogen atom with alkali metal cation. The increasing values of dipole moment and decreasing values of total energy in the order: linoleic/oleic acid→lithium→sodium→potassium linoleates/oleinates indicate an increase in stability of the compounds.

Conformational, electronic, and spectroscopic characterization of isophthalic acid (monomer and dimer structures) experimentally and by DFT

NASA Astrophysics Data System (ADS)

Bardak, F.; Karaca, C.; Bilgili, S.; Atac, A.; Mavis, T.; Asiri, A. M.; Karabacak, M.; Kose, E.

2016-08-01

Isophthalic acid (C6H4(CO2H)2) is a noteworthy organic compound widely used in coating and synthesis of resins and the production of commercially important polymers such as drink plastic bottles. The effects of isophthalic acid (IPA) on human health, toxicology, and biodegradability are the main focus of many researchers. Because structural and spectroscopic investigation of molecules provides a deep understanding of interactional behaviors of compounds, this study stands for exploring those features. Therefore, the spectroscopic, structural, electronic, and thermodynamical properties of IPA were thoroughly studied in this work experimentally using UV-Vis, 1H and 13C NMR, FT-IR, FT-Raman and theoretically via DFT and TD-DFT calculations. The UV-Vis absorption spectrum in water was taken in the region 200-400 nm. The NMR chemical shifts (1H and 13C) were recorded in DMSO solution. The infrared and Raman spectra of the solid IPA were recorded in the range of 4000-400 cm- 1 and 3500-50 cm- 1, respectively. DFT and TD-DFT calculations were performed at the level of B3LYP/6-311++G(d,p) in determination of geometrical structure, electronic structure analysis and normal mode. The 13C and 1H nuclear magnetic resonance (NMR) spectra were estimated by using the gauge-invariant atomic orbital (GIAO) method. The scaled quantum mechanics (SQM) method was used to determine the total energy distribution (TED) to assign the vibrational modes accurately. Weak interactions such as hydrogen bonding and Van der Walls were analyzed via reduced density gradient (RDG) analysis in monomeric and dimeric forms. Furthermore, the excitation energies, density of state (DOS) diagram, thermodynamical properties, molecular electro-static potential (MEP), and nonlinear optical (NLO) properties were obtained.

Dye-sensitized solar cells and complexes between pyridines and iodines. A NMR, IR and DFT study.

PubMed

Hansen, Poul Erik; Nguyen, Phuong Tuyet; Krake, Jacob; Spanget-Larsen, Jens; Lund, Torben

2012-12-01

Interactions between triiodide (I(3)(-)) and 4-tert-butylpyridine (4TBP) as postulated in dye-sensitized solar cells (DSC) are investigated by means of (13)C NMR and IR spectroscopy supported by DFT calculations. The charge transfer (CT) complex 4TBP·I(2) and potential salts such as (4TBP)(2)I(+), I(3)(-) were synthesized and characterized by IR and (13)C NMR spectroscopy. However, mixing (butyl)(4)N(+), I(3)(-) and 4TBP at concentrations comparable to those of the DSC solar cell did not lead to any reaction. Neither CT complexes nor cationic species like (4TBP)(2)I(+) were observed, judging from the (13)C NMR spectroscopic evidence. This questions the previously proposed formation of (4TBP)(2)I(+) in DSC cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Generation of photocurrent by visible-light irradiation of conjugated dawson polyoxophosphovanadotungstate-porphyrin copolymers.

PubMed

Azcarate, Iban; Huo, Zhaohui; Farha, Rana; Goldmann, Michel; Xu, Hualong; Hasenknopf, Bernold; Lacôte, Emmanuel; Ruhlmann, Laurent

2015-05-26

Four hybrid polyoxometalate-porphyrin copolymer films were obtained by the electrooxidation of zinc octaethylporphyrin in the presence of four different Dawson-type polyoxometalates bearing two pyridyl groups (POM(py)2) with various spacers. The POM monomers were designed around 1,3,5-trisubstituted benzene rings. Two of the substituents of the benzene ring are linked to the pyridyl groups, and the third is connected to the POM subunit. The four monomers vary in the relative positions of the nitrogen atoms of the pyridine rings or in the distance from the carbonyl group. The monomers were fully characterized by (1)H, (31)P, and (13)C NMR spectroscopy, electrospray mass spectrometry, IR and UV/Vis spectroscopy, and electrochemistry. The copolymers were characterized by UV/Vis spectroscopy, X-ray photoelectron spectroscopy, electrochemistry, and AFM. Their photovoltaic performance under visible light irradiation was investigated by photocurrent transient measurements under visible illumination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photo-reorganization of 3-alkoxy-6-chloro-2-(benzo[b]thiophen-2-yl)-4H-chromen-4-ones: a green and convenient synthesis of angular pentacyclics.

PubMed

Dalal, Aarti; Khanna, Radhika; Kumar, Parvin; Kamboj, Ramesh C

2017-05-17

Photo-reorganization of 3-alkoxy-6-chloro-2-(benzo[b]thiophen-2-yl)-4H-chromen-4-ones in methanol with Pyrex filtered UV-light from a medium pressure 125 W Hg-vapor lamp led to the formation of angular pentacyclic compounds (dihydro and aromatic products) along with some rearranged chromenones where the product(s) distribution depended upon the structure of 3-alkoxy groups (methoxy, ethoxy, allyloxy and benzyloxy). The phenyl moiety in the 3-benzyloxy group had a profound effect on the dihydro product(s) formation as the latter was in high yield when the alkoxy group was benzyloxy followed by allyloxy, ethoxy and methoxy groups. The present photochemical study represents a general method for the synthesis of some angular pentacyclic - benzothiophene fused xanthenone derivatives in a single step without using any specific and toxic reagent. The structures of the new organic scaffolds obtained were established by their spectral data (UV, IR and NMR).

Potentiometric and Conductometric Study of Aqueous Solutions of Lithium and Sodium Salts of Poly(thiophen-3-ylacetic acid).

PubMed

Hostnik, Gregor; Vlachy, Vojko; Bondarev, Dmitrij; Jiří, Vohlídal; Cerar, Janez

2012-09-01

The title polymer, PTAA, practically free of ester groups was obtained by oxidative polymerization of methyl thiophen-3-ylacetate and subsequent basic hydrolysis of primary polymer. Poly(thiophen-3-ylacetic acid) has been thoroughly characterized by NMR, IR, Raman, and UV/Vis spectroscopy. The polyacid behavior during neutralization titrations with lithium and sodium hydroxides, carried out under nitrogen atmosphere, has been studied by conductometry and potentiometry. Henderson-Hasselbach plots of potentiometric titration curves show a break point at pH around 6, where the curve slope drops from 1.8 (at lower pH) to a value from 1.05 to 1.3 (at higher pH values). The UV/Vis spectra monitored during back titration show: (i) monotonous decrease of both λmax and εmax as pH decreases, (ii) the presence of the isosbestic point at 401 nm that can be ascribed to conformational transition of PTAA chains, and (iii) absence of the isosbestic point at 392 nm reported previously by other authors.

Optical, Fluorescence with quantum analysis of hydrazine (1, 3- Dinitro Phenyl) by DFT and Ab initio approach

NASA Astrophysics Data System (ADS)

Cecily Mary Glory, D.; Sambathkumar, K.; Madivanane, R.; Velmurugan, G.; Gayathri, R.; Nithiyanantham, S.; Venkatachalapathy, M.; Rajkamal, N.

2018-07-01

Experimental and computational study of molecular structure, vibrational and UV-spectral analysis of Hydrazine (1, 3- Dinitrophenyl) (HDP) derivatives. The crystal was grown by slow cooling method and the crystalline perfection of single crystals was evaluated by high resolution X-ray diffractometry (HRXRD) using a multicrystal X-ray diffractometer. Fluorescence, FT-IR and FT-Raman spectra of HDP crystal were recorded. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) followed by scaled quantum force field methodology (SQMFF). NMR studies have confirmed respectively the crystal structure and functional groups of the grown crystal. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) result complements the experimental findings. The calculated MESP, UV, HOMO-LUMO energies show that charge transfer done within the molecule. And various thermodynamic parameters are studied. Fukui determines the local reactive site of electrophilic, nucleophilic, descriptor.

Isolation, characterization, spectroscopic properties and quantum chemical computations of an important phytoalexin resveratrol as antioxidant component from Vitis labrusca L. and their chemical compositions.

PubMed

Güder, Aytaç; Korkmaz, Halil; Gökce, Halil; Alpaslan, Yelda Bingöl; Alpaslan, Gökhan

2014-12-10

In this study, isolation and characterization of trans-resveratrol (RES) as an antioxidant compound were carried out from VLE, VLG and VLS. Furthermore, antioxidant activities were evaluated by using six different methods. Finally, total phenolic, flavonoid, ascorbic acid, anthocyanin, lycopene, β-carotene and vitamin E contents were carried out. In addition, the FT-IR, (13)C and (1)H NMR chemical shifts and UV-vis. spectra of trans-resveratrol were experimentally recorded. Quantum chemical computations such as the molecular geometry, vibrational frequencies, UV-vis. spectroscopic parameters, HOMOs-LUMOs energies, molecular electrostatic potential (MEP), natural bond orbitals (NBO) and nonlinear optics (NLO) properties of title molecule have been calculated by using DFT/B3PW91 method with 6-311++G(d,p) basis set in ground state for the first time. The obtained results show that the calculated spectroscopic data are in a good agreement with experimental data. Copyright © 2014 Elsevier B.V. All rights reserved.

Isolation, characterization, spectroscopic properties and quantum chemical computations of an important phytoalexin resveratrol as antioxidant component from Vitis labrusca L. and their chemical compositions

NASA Astrophysics Data System (ADS)

Güder, Aytaç; Korkmaz, Halil; Gökce, Halil; Alpaslan, Yelda Bingöl; Alpaslan, Gökhan

2014-12-01

In this study, isolation and characterization of trans-resveratrol (RES) as an antioxidant compound were carried out from VLE, VLG and VLS. Furthermore, antioxidant activities were evaluated by using six different methods. Finally, total phenolic, flavonoid, ascorbic acid, anthocyanin, lycopene, β-carotene and vitamin E contents were carried out. In addition, the FT-IR, 13C and 1H NMR chemical shifts and UV-vis. spectra of trans-resveratrol were experimentally recorded. Quantum chemical computations such as the molecular geometry, vibrational frequencies, UV-vis. spectroscopic parameters, HOMOs-LUMOs energies, molecular electrostatic potential (MEP), natural bond orbitals (NBO) and nonlinear optics (NLO) properties of title molecule have been calculated by using DFT/B3PW91 method with 6-311++G(d,p) basis set in ground state for the first time. The obtained results show that the calculated spectroscopic data are in a good agreement with experimental data.

An Octanuclear Metallosupramolecular Cage Designed To Exhibit Spin-Crossover Behavior.

PubMed

Struch, Niklas; Bannwarth, Christoph; Ronson, Tanya K; Lorenz, Yvonne; Mienert, Bernd; Wagner, Norbert; Engeser, Marianne; Bill, Eckhard; Puttreddy, Rakesh; Rissanen, Kari; Beck, Johannes; Grimme, Stefan; Nitschke, Jonathan R; Lützen, Arne

2017-04-24

By employing the subcomponent self-assembly approach utilizing 5,10,15,20-tetrakis(4-aminophenyl)porphyrin or its zinc(II) complex, 1H-4-imidazolecarbaldehyde, and either zinc(II) or iron(II) salts, we were able to prepare O-symmetric cages having a confined volume of ca. 1300 Å 3 . The use of iron(II) salts yielded coordination cages in the high-spin state at room temperature, manifesting spin-crossover in solution at low temperatures, whereas corresponding zinc(II) salts led to the corresponding diamagnetic analogues. The new cages were characterized by synchrotron X-ray crystallography, high-resolution mass spectrometry, and NMR, Mössbauer, IR, and UV/Vis spectroscopy. The cage structures and UV/Vis spectra were independently confirmed by state-of-the-art DFT calculations. A remarkably high-spin-stabilizing effect through encapsulation of C 70 was observed. The spin-transition temperature T 1/2 is lowered by 20 K in the host-guest complex. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, growth, structure and nonlinear optical properties of a semiorganic 2-carboxy pyridinium dihydrogen phosphate single crystal

NASA Astrophysics Data System (ADS)

Nagapandiselvi, P.; Baby, C.; Gopalakrishnan, R.

2015-09-01

A new semiorganic compound namely, 2-carboxy pyridinium dihydrogen phosphate (2CPDP) was synthesised and grown as single crystals by slow evaporation solution growth technique. Single crystal XRD showed that 2CPDP belongs to monoclinic crystal system with space group P21/n. The molecular structure was further confirmed by modern spectroscopic techniques like FT-NMR (1H, 13C &31P), FT-IR, UV-Vis-NIR and Fluorescence. The UV-Vis-NIR analysis revealed suitability of the crystal for nonlinear optical applications. The photo active nature of the material is established from fluorescence studies. TG-DSC analysis showed that 2CPDP was thermally stable up to 170 °C. The dependence of dielectric properties on frequency and temperature were also studied. Nonlinear optical absorption determined from open aperture Z-Scan analysis by employing picosecond Nd-YAG laser, revealed that 2CPDP can serve as a promising candidate for optical limiting applications.

Digital UV/IR photography for tattoo evaluation in mummified remains.

PubMed

Oliver, William R; Leone, Lisa

2012-07-01

The presence and location of tattoos can be an important component in the identification of remains in the extended postmortem period if remnants of skin persist. However, when there is significant mummification, visualization of tattoos can be problematic. Multiple methods have been proposed to make tattoos more visible, but all have limitation. In this case report, a mummified body was discovered. The presumptive victim was reported to have a small tattoo on her hand but it was not visible to the naked eye. The hand was photographed using ultraviolet (UV) and infrared (IR) light. A tattoo matching the description was noted in the photographs. In contrast to film-based IR and UV photography, digital UV and IR photography allows rapid visual evaluation of results and optimization of image utility. The ability to quickly modify photographic parameters quickly greatly increases the utility of IR and UV photography in the autopsy suite. © 2012 American Academy of Forensic Sciences.

Investigation of synthesized new vanadium(III) complexes of ditolyldithiophosphate ligands by spectroscopic, cyclic voltammetric, DFT, antimicrobial and cytotoxic studies

NASA Astrophysics Data System (ADS)

Kumar, Sandeep; Syed, Atiya; Andotra, Savit; Kaur, Ramanpreet; Vikas; Pandey, Sushil K.

2018-02-01

Vanadium(III) complexes with sulfur donor dithiophosphate ligands corresponding to [{(ArO)2PS2}3V] and [{(ArO)2PS2}2VCl.L] (Ar = o-, m-, p-CH3C6H4 and p-Cl-m-CH3C6H3; L = NC5H5, P(C6H5)3, have been synthesized and characterized by various physico-chemical techniques like elemental analyses, magnetic studies, ESI-Mass, IR, UV and heteronuclear NMR (1H, 13C and 31P) spectral studies. These analyses have contributed to the prediction of structure: by exhibiting significant v(P-S) and v(Pdbnd S) band shifting in comparative IR spectra; shifting of resonance signal in comparative 31P NMR spectra of ligands and complexes and stability of V(III) ion in the complexed state is confirmed by magnetic and UV studies. Therefore, the six coordinated geometry stabilizing the trivalent vanadium atom in the complexes and adducts, respectively has been confirmed. The cyclic voltammetric analyses presented the redox aptitude of the complex under analysis which can be utilized as catalyst in organic synthesis. The geometry of ligands and complexes has been optimized using density functional theory (DFT). The structural parameters, vibrational bands and energy gaps of frontier orbitals (HOMO-LUMO) have also been calculated. The calculated geometric and spectral results reproduced the experimental data with well agreement. The DFT computed frontier molecular orbitals (HOMO-LUMO) and their energies suggest charge transfer occurs within the complexes. Antimicrobial screening of the complexes against two bacterial strains: Gram-positive, Enterrococcus faecalis and Gram-negative, Eischerichia coli and fungus Fusarium oxysporum have shown potential bioactivity. A preliminary cytotoxic analysis has been carried out using the cultivated human cell lines: lung adeno carcinoma cell line A-549, leukemia cell line THP-1, prostate cancer cell line PC3 and colorectal cancer cell line HCT-116.

NMR, FT-IR, Raman and UV-Vis spectroscopic investigation and DFT study of 6-Bromo-3-Pyridinyl Boronic Acid

NASA Astrophysics Data System (ADS)

Dikmen, Gökhan; Alver, Özgür

2015-11-01

Possible stable conformers and geometrical molecular structures of 6-Bromo-3-Pyridinyl Boronic acid (6B3PBA; C5H5BBrNO2) were studied experimentally and theoretically using FT-IR and Raman spectroscopic methods. FT-IR and Raman spectra were recorded in the region of 4000-400 cm-1 and 3700-400 cm-1, respectively. The structural properties were investigated further, using 1H, 13C, 1H coupled 13C, HETCOR, COSY and APT NMR techniques. The optimized geometric structures were searched by Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. Vibrational wavenumbers of 6B3PBA were calculated whereby B3LYP density functional methods including 6-311++G(d, p), 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. The comparison of the experimentally and theoretically obtained results using mean absolute error and experimental versus calculated correlation coefficients for the vibrational wavenumbers indicates that B3LYP method with 6-311++G(d, p) gives more satisfactory results for predicting vibrational wavenumbers when compared to the 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. However, this method and none of the mentioned methods here seem suitable for the calculations of OH stretching modes, most likely because increasing unharmonicity in the high wave number region and possible intra and inter molecular interactions at OH edges lead some deviations between experimental and theoretical results. Moreover, reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated using scaled quantum mechanical (SQM) method.

Spectroscopic (FT-IR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of organic 2,4,5-trichloroaniline.

PubMed

Govindarajan, M; Karabacak, M; Periandy, S; Tanuja, D

2012-11-01

In this work, the experimental and theoretical study on the molecular structure and vibrational spectra of 2,4,5-trichloroaniline (C(6)H(4)NCl(3), abbreviated as 2,4,5-TClA) were studied. The FT-IR and FT-Raman spectra were recorded. The molecular geometry and vibrational frequencies in the ground state were calculated by using the Hartree-Fock (HF) and density functional theory (DFT) methods (B3LYP) with 6-311++G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of 2,4,5-TClA with calculated results by HF and DFT indicates that B3LYP is superior to HF method for molecular vibrational problems. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and the first hyperpolarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4,5-TClA molecule may have microscopic nonlinear optical (NLO) behavior with non-zero values. Mulliken atomic charges of 2,4,5-TClA was calculated and compared with aniline and chlorobenzene molecules. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of the substituents on the photophysical, electrochemical and electroluminescence properties of OLED dopant Iridium bis(2-phenylbenzothiozolato- N,C2')(acetylacetonate)

NASA Astrophysics Data System (ADS)

Ivanov, P.; Tomova, R.; Petrova, P.

2014-12-01

The effect of two substituents: clorine and 1,3-diphenylpropane-1,3-dionate, placed on different position in the molecule of Iridium (III) bis(2-phenylbenzothiozolato-N,C2')- (acetylacetonate) (bt)2Ir(acac), on its electrochemical behaviour, photophysical and electroluminescence properties were investigated. Three complexes (bt)2Ir(acac), Iridium (III) bis[2-(4-chlorophenyl)benzothiazolato-N,C2']-acetylacetonate (Clbt)2Ir(acac), in which the Cl atom was introduced on the 4-position in the benzothiazole ring, and the new Iridium (Ill) bis[2 -phenylbenzothiazolato -N,C2'] -(1,3 -diphenylpropane-1,3 -dionate) (bt)2Ir(dbm), where ancillary acetylacetonate ligand was replaced by 1,3-diphenylpropane-1,3-dionate, were synthesized and characterised by 1H-NMR and elemental analysis. The HOMO/LUMO energy levels of the complexes were determined by cyclic voltammetry (CV) and their properties were established by UV-Visible and fluorescence spectroscopy. The application of (Clbt)2Ir(acac), (bt)2Ir(bsm) and (bt)2Ir(acac) as dopants in hole transporting layer (HTL) of Organic light- emitting diodes(OLEDs). It was found that with respect to the reference (bt)2Ir(acac): both LUMO and HOMO of the substituted complexes were shifted to more positive values accordingly with 0.23 and 0.19 eV for (Clbt)2Ir(acac) and 0.14 and 0.12 eV for (bt)2Ir(dbm). OLEDs doped with 1 w% of the complexes irradiated the warm white light with Commission internationale de l'eclairage (CIE) coordinates: 0.24;0.38 for (Clbt)2Ir(acac), 0.30;0.44 for (bt)2Ir(acac) and 0.28;0.46 for (bt)2Ir(dbm). Devices doped with 10 w% of all complexes irradiated in the yellow orange region of the spectrum.

Use of diffusion-ordered NMR spectroscopy and HPLC-UV-SPE-NMR to identify undeclared synthetic drugs in medicines illegally sold as phytotherapies.

PubMed

Silva, Lorena M A; Filho, Elenilson G A; Thomasi, Sérgio S; Silva, Bianca F; Ferreira, Antonio G; Venâncio, Tiago

2013-09-01

The informal (and/or illegal) e-commerce of pharmaceutical formulations causes problems that governmental health agencies find hard to control, one of which concerns formulas sold as natural products. The purpose of this work was to explore the advantages and limitations of DOSY and HPLC-UV-SPE-NMR. These techniques were used to identify the components of a formula illegally marketed in Brazil as an herbal medicine possessing anti-inflammatory and analgesic properties. DOSY was able to detect the major components present at higher concentrations. Complete characterization was achieved using HPLC-UV-SPE-NMR, and 1D and 2D NMR analyses enabled the identification of known synthetic drugs. These were ranitidine and a mixture of orphenadrine citrate, piroxicam, and dexamethasone, which are co-formulated in a remedy called Rheumazim that is used to relieve severe pain, but it is prohibited in Brazil because of a lack of sufficient pharmacokinetic and pharmacodynamic information. Copyright © 2013 John Wiley & Sons, Ltd.

Synthesis, spectroscopic, molecular structure, antioxidant, antimicrobial and antitumor behavior of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of O2N type tridentate chromone-2-carboxaldehyde Schiff's base ligand

NASA Astrophysics Data System (ADS)

Ammar, Reda A.; Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Al-Bedair, Lamia A.

2017-08-01

Tridentate Schiff's base (HL) ligand was synthesized via condensation of salicylaldehyde and 3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR), magnetic moment, EPR, and thermal measurements. The IR spectra showed that HL was coordinated to the metal ions in tridentate manner with O2N donor sites of the azomethine N, deprotonated phenolic-OH and carbonyl-O. The activation of thermodynamic parameters are calculated using Coast-Redfern and Horowitz-Metzger (HM). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations, UV-Vis and magnetic moment measurements, ESR and ligand field parameters. Antioxidant activities have also been performed for all the compounds. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all inspected compounds were evaluated towards human liver Carcinoma (HepG2) cell line.

Synthesis, structural, conformational and pharmacological study of some amides derived from 3 -methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-amine

NASA Astrophysics Data System (ADS)

Iriepa, I.; Bellanato, J.; Gálvez, E.; Gil-Alberdi, B.

2010-07-01

Some mono-substituted amides ( 2- 5) derived from 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-amine were synthesized and studied by IR, 1H and 13C NMR spectroscopy. The crystal structure of 3-methyl-2,4-diphenyl-9α-(3,5-dichlorobenzamido)-3-azabicyclo[3.3.1]nonane ( 3) was determined by X-ray diffraction. NMR data showed that all compounds adopt in CDCl 3 a preferred flattened chair-chair conformation with the N-CH 3 group in equatorial disposition. X-ray data agreed with this conformation in the case of compound 3. IR data revealed that compounds 2 and 3 present a C dbnd O⋯HN intermolecular bond in the solid state. This conclusion was also confirmed by X-ray data of compound 3. In the case of compound 5, IR results suggested intermolecular NH⋯N-heterocyclic bonding. On the contrary, in the pyrazine derivative ( 4), IR, 1H and 13C NMR data showed the presence of an intramolecular NH⋯N1″-heterocyclic hydrogen bond in the solid state and solution. Moreover, NMR and IR data showed a preferred trans disposition for the NH-C dbnd O group. NMR also revealed free rotation of the -NH-CO-R group around C9-NH bond. Pharmacological assays on mice were drawn to evaluate analgesic activity.

Molecular structure, NMR, UV-Visible, vibrational spectroscopic and HOMO, LUMO analysis of (E)-1-(2, 6-bis (4-methoxyphenyl)-3, 3-dimethylpiperidine-4-ylidene)-2-(3-(3, 5-dimethyl-1H-pyrazol-1-yl) pyrazin-2-yl) hydrazine by DFT method

NASA Astrophysics Data System (ADS)

Alphonsa, A. Therasa; Loganathan, C.; Anand, S. Athavan Alias; Kabilan, S.

2016-02-01

We have synthesized (E)-1-(2, 6-bis (4-methoxyphenyl)-3, 3-dimethylpiperidine-4-ylidene)-2-(3-(3, 5-dimethyl-1H-pyrazol-1-yl) pyrazin-2-yl) hydrazine (PM6). It was characterized using FT-IR, FT-Raman, 1H NMR, 13C NMR techniques. To interpret the experimental data, ab initio computations of the vibrational frequencies were carried out using the Gaussian 09 program followed by the full optimizations done using Density Functional Theory (DFT) at B3LYP/6-311 G(d,p) level. The combined use of experiments and computations allowed a firm assignment of the majority of observed bands for the compound. The calculated stretching frequencies have been found to be in good agreement with the experimental frequencies. The electronic and charge transfer properties have been explained on the basis of highest occupied molecular orbitals (HOMOs), lowest unoccupied molecular orbitals (LUMOs) and density of states (DOS). The absorption spectra have been computed by using time dependent density functional theory (TD-DFT). 1H and 13C NMR spectra were recorded and 1H and 13C NMR chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. From the optimized geometry of the molecule, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMOs) of the title compound have been calculated in the ground state theoretically. The theoretical results showed good agreement with the experimental values.

One-pot three-component Biginelli-type reaction to synthesize 3,4-dihydropyrimidine-2-(1H)-ones catalyzed by Co phthalocyanines: Synthesis, characterization, aggregation behavior and antibacterial activity.

PubMed

Medyouni, Rawdha; Elgabsi, Wissal; Naouali, Olfa; Romerosa, Antonio; Sulaiman Al-Ayed, Abdullah; Baklouti, Lasaad; Hamdi, Naceur

2016-10-05

The synthesis of a novel phthalonitrile derivative with pyridine-2-thiol and 2,4,6-trimethylphenylamine substituents functionalized groups and its peripherally tetrasubstituted cobalt phthalocyanine and cationic phthalocyanines complexes were reported. The aggregation investigations carried out in different concentrations indicate that Co Phthalocyanines compounds 3,4 do not have any aggregation behavior for the concentration range of 6×10(-4)-14×10(-6)M in DMSO. The ion binding properties of Co Phthalocyanines compounds 3,4 show the formation of stable complex with Co(2+). In addition 3,4-Dihydropyrimidin-2(1H)-one derivatives were synthesized by modified Biginelli cyclocondensation reaction catalyzed by MPc as Lewis base. The structures of the synthesized compounds have been successfully characterized by the spectroscopic methods (IR, (1)H NMR, (13C)NMR, UV-Vis, mass spectrometry, elemental analysis and NMR 2D). The influence of substrate/catalyst ratio, solvent was also investigated to find optimal reaction on this synthesis for getting the highest conversion. Different parameters were examined for finding optimal conditions of catalysis. In addition; the compounds 3-11 were investigated for antimicrobial activity. Most of them exhibited important antimicrobial activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis, X-ray crystallography, thermal studies, spectroscopic and electrochemistry investigations of uranyl Schiff base complexes.

PubMed

Asadi, Zahra; Shorkaei, Mohammad Ranjkesh

2013-03-15

Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV-Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible. Copyright © 2012 Elsevier B.V. All rights reserved.

[Synthesis, characterization and fluorescent properties of copper phthalocyanine derivates substituted by aliphatic alcohol].

PubMed

Zhang, Liang; Xu, Qing-Feng; Lu, Jian-Mei; Yao, She-Chun

2007-04-01

A series of copper phthalocyanine derivatives substituted by aliphatic chain were obtained by the reaction of tetra-formyl chloride copper phthalocyanine and aliphatic alcohol such as n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-caprylic alcohol and lauryl alcohol. IR, UV-Vis, elemental analysis and 1H NMR verified the structures and substituting degree. The solubility and the relationship between fluorescence and concentration and substituting group were studied in organic solution. It was confirmed that the solubility in organic solution was improved greatly, the fluorescence did not change in linear according to the concentration and the fluorescence of copper phthalocyanine derivatives substituted by the long alkyl was stronger than that substituted by the relatively short alkyl.

Solid state synthesis of chitosan and its unsaturated derivatives for laser microfabrication of 3D scaffolds

NASA Astrophysics Data System (ADS)

Akopova, T. A.; Demina, T. S.; Bagratashvili, V. N.; Bardakova, K. N.; Novikov, M. M.; Selezneva, I. I.; Istomin, A. V.; Svidchenko, E. A.; Cherkaev, G. V.; Surin, N. M.; Timashev, P. S.

2015-07-01

Chitosans with various degrees of deacetylation and molecular weights and their allyl substituted derivatives were obtained through a solvent-free reaction under shear deformation in an extruder. Structure and physical-chemical analysis of the samples were carried out using nuclear magnetic resonance (NMR), ultraviolet (UV) and infrared radiation (IR) spectroscopy. Photosensitive materials based on the synthesized polymers were successfully used for microfabrication of 3D well-defined architectonic structures by laser stereolithography. Study on the metabolic activity of NCTC L929 cultured in the presence of the cured chitosan extracts indicates that the engineered biomaterials could support adhesion, spreading and growth of adherent-dependent cells, and thus could be considered as biocompatible scaffolds.

Gold glyconanoparticles: synthetic polyvalent ligands mimicking glycocalyx-like surfaces as tools for glycobiological studies.

PubMed

Barrientos, Africa G; de la Fuente, Jesús M; Rojas, Teresa C; Fernández, Asunción; Penadés, Soledad

2003-05-09

A simple and versatile methodology is described for tailoring sugar-functionalised gold nanoclusters (glyconanoparticles) that have 3D polyvalent carbohydrate display and globular shapes. This methodology allows the preparation of glyconanoparticles with biologically significant oligosaccharides as well as with differing carbohydrate density. Fluorescent glyconanoparticles have been also prepared for labelling cells in biological tests. The materials are water soluble, stable under physiological conditions and present an exceptional small core size. All of them have been characterised by (1)H NMR, UV and IR spectroscopy, TEM and elemental analysis. Their highly polyvalent network can mimic glycosphingolipid clustering and interactions at the plasma membrane, providing an controlled system for glycobiological studies. Furthermore, they are useful building blocks for the design of nanomaterials.

Bio-important antipyrine derived Schiff bases and their transition metal complexes: Synthesis, spectroscopic characterization, antimicrobial, anthelmintic and DNA cleavage investigation

NASA Astrophysics Data System (ADS)

Manjunath, M.; Kulkarni, Ajaykumar D.; Bagihalli, Gangadhar B.; Malladi, Shridhar; Patil, Sangamesh A.

2017-01-01

Spectroscopic (IR, NMR, UV-vis, ESR, ESI-mass), magnetic and TGA studies suggests octahedral geometry for all the CoII, NiII and CuII complexes of the Schiff bases, derived from 4-aminoantipyrine and 8-formyl-7-Hydroxy-4-methylcoumarin/5-formyl-6-hydroxycoumarin, coordinated through ONO donor sites. Antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi), antifungal (Aspergillus niger, Aspergillus flavus and Cladosporium) and DNA cleavage properties of the metal complexes are investigated. The results suggested that some of the synthesized compounds are potential antimicrobials. The synthesized compounds tested for their anthelmintic activities and it was found that CoII and NiII complexes exhibited good anthelmintic properties.

Synthesis, characterization and antioxidant activity copper-quercetin complex.

PubMed

Bukhari, S Birjees; Memon, Shahabuddin; Mahroof-Tahir, M; Bhanger, M I

2009-01-01

Quercetin (3,3',4',5,7-pentahydroxyflavone) one of the most abundant dietary flavonoids, has been investigated in the presence of Cu(II) in methanol. The spectroscopic studies (UV-vis, (1)H NMR and IR) were useful to assess the relevant interaction of Quercetin with Cu(II) ions, the chelation sites and dependence of the complex structure from the metal/ligand ratio. A 1:2 (L:M) complex was indicated by Job's method of continuous variation, which was applied to ascertain the stoichiometric composition of the complex. The antioxidant activities of the compounds were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The complexed flavonoid was much more effective free radical scavengers than the free flavonoids.

Synthesis, characterization and antioxidant activity copper-quercetin complex

NASA Astrophysics Data System (ADS)

Bukhari, S. Birjees; Memon, Shahabuddin; Mahroof-Tahir, M.; Bhanger, M. I.

2009-01-01

Quercetin (3,3',4',5,7-pentahydroxyflavone) one of the most abundant dietary flavonoids, has been investigated in the presence of Cu(II) in methanol. The spectroscopic studies (UV-vis, 1H NMR and IR) were useful to assess the relevant interaction of Quercetin with Cu(II) ions, the chelation sites and dependence of the complex structure from the metal/ligand ratio. A 1:2 (L:M) complex was indicated by Job's method of continuous variation, which was applied to ascertain the stoichiometric composition of the complex. The antioxidant activities of the compounds were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The complexed flavonoid was much more effective free radical scavengers than the free flavonoids.

Applications of several spectral techniques to characterize coordination compounds derived from 2,6-diacetylpyridine derivative

NASA Astrophysics Data System (ADS)

Chandra, Sulekh; Sharma, Amit Kumar

2009-09-01

The coordination compounds of Cr III, Mn II and Co II metal ions derived from quinquedentate 2,6-diacetylpyridine derivative have been synthesized and characterized by using the various physicochemical studies like stoichiometric, molar conductivity and magnetic, and spectral techniques like IR, NMR, mass, UV and EPR. The general stoichiometries of the complexes are found to be [Cr(H 2L)X] and [M(HL)X], where M = Mn(II) and Co(II); H 2L = dideprotonated ligand, HL = monodeprotonated ligand and X = NO 3-, Cl - and OAc -. The studies reveal that the complexes possess monomeric compositions with six coordinated octahedral geometry (Cr III and Mn II complexes) and six coordinated tetragonal geometry (Co II complexes).

Isolation and anti-hepatitis B virus activity of dibenzocyclooctadiene lignans from the fruits of Schisandra chinensis.

PubMed

Xue, Yongbo; Li, Xifeng; Du, Xue; Li, Xiaonian; Wang, Weiguang; Yang, Jianhong; Chen, Jijun; Pu, Jianxin; Sun, Handong

2015-08-01

Seven lignans with a dibenzocyclooctadiene skeleton, termed schinlignans A-G, and a 6,7-seco-homolignan, schischinone, together with seven known lignans, were isolated from the fruits of Schisandra chinensis (Turcz.) Baill. Their structures were elucidated by extensive spectroscopic methods, including HRESIMS, IR, UV, and 2D NMR (COSY, HMQC, COSY, and HMBC experiments). The stereochemistry at the chiral centers and the biphenyl moiety, were determined using ROESY, as well as via interpretation of their ECD spectra. Schinlignan G and methylgomisin O exhibited potent anti-hepatitis B virus activity against HBV DNA replication with IC50 values of 5.13 and 5.49μgmL(-1), respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of new bioactive aminophosphonates and study of their antioxidant, anti-inflammatory and antibacterial activities as well the assessment of their toxicological activity

NASA Astrophysics Data System (ADS)

Damiche, Rebiha; Chafaa, Salah

2017-02-01

Two new categories of α-aminophosphonates molecules were synthesized and characterized by UV-Vis, IR, and NMR. Their spectral properties show a perfect convergence. Their biological activities were evaluated. Molecules 1a, 2a, and 1d present a greater antioxidant potential than BHT and vitamin C. The best anti-inflammatory activity is shown by the 2b molecule and that of 1a, 2a, and 2c molecules are closely comparable to that of diclofenac. The antibacterial activity of the synthesized compounds is significantly higher than the antibiotic amoxicillin. The hemolysis rate HR of compounds 1b, 1c, 2b, and 2c was lower than 5%.

Synthesis, characterization and vibrational properties of p-fluorosulfinylaniline.

PubMed

Páez Jerez, Ana L; Flores Antognini, Andrea; Cutin, Edgardo H; Robles, Norma L

2015-02-25

The reaction of p-fluoroaniline and SOCl2 rendered p-fluorosulfinylaniline in good yield. The obtained dark yellowish liquid compound was characterized by NMR, UV-visible, FT-IR and Raman spectroscopies. The observed features were consistent with the existence of only one conformer, belonging to the CS symmetry group. A tentative assignment of the vibrational modes was performed on the basis of experimental spectra and quantum chemical calculations at different levels of theory (B3LYP and MP2 with 6-31+G(d), 6-311+G(d) and 6-311+G(df) basis sets). The conformational and vibrational properties of p-fluorosulfinylaniline were in good agreement with experimental data reported for other substituted sulfinylanilines and p-halogenanilines. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel antibacterial and antifungal phenolic compound from the endophytic fungus Pestalotiopsis mangiferae.

PubMed

Subban, Kamalraj; Subramani, Ramesh; Johnpaul, Muthumary

2013-01-01

A novel phenolic compound, 4-(2,4,7-trioxa-bicyclo[4.1.0]heptan-3-yl) phenol (1), was isolated from Pestalotiopsis mangiferae, an endophytic fungus associated with Mangifera indica Linn. The structure of the compound was elucidated on the basis of comprehensive spectral analysis (UV, IR, ¹H-, ¹³C- and 2D-NMR, as well as HRESI-MS). Compound (1) shows potent antibacterial and antifungal activity against Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa and Candida albicans. The transmission electron microscope study for the mode of inhibition of compound (1) on bacterial pathogens revealed the destruction of bacterial cells by cytoplasm agglutination with the formation of pores in cell wall membranes.

Two novel macroacyclic schiff bases containing bis-N 2O 2 donor set and their binuclear complexes: synthesis, spectroscopic and magnetic properties

NASA Astrophysics Data System (ADS)

Karaoglu, Kaan; Baran, Talat; Serbest, Kerim; Er, Mustafa; Degirmencioglu, Ismail

2009-03-01

Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative compound and their binuclear Mn(II), Ni(II), Cu(II) and Zn(II) complexes. The structures of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-Vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The stoichiometries of the complexes derived from mass and elemental analysis correspond to the general formula [M 2L(ClO 4) n](ClO 4) 4-n, (where M is Mn(II), Ni(II), Cu(II), Zn(II) and L represents the Schiff base ligands).

Gem-Dialkoxylation of 2-acetylthiophenes and 2-acetylfurans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordeeva, G.N.; Kalashnikov, S.M.; Popov, Yu.N.

1987-12-01

Reaction of 2-acetyl-substituted thiophenes and furans with alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear acetals of thienyl- and furylglyoxals, whose structure was established by IR, UV, NMR spectroscopy, and mass spectrometry methods. The main paths of the dissociation of the molecules under electron impact were established. The chemical shifts of the carbon atoms, contained in the hetero rings, are present in the 109-158 ppm region; their assignment was made on the basis of the multiplicity of signals in the spectra without suppression of the HFI with protons, andmore » also with consideration of the influence of the substituents on the electron density distribution in the hetero ring.« less

Sea anemone Radianthus macrodactylus--a new source of palytoxin.

PubMed

Mahnir, V M; Kozlovskaya, E P; Kalinovsky, A I

1992-11-01

A very potent non-protein toxin was isolated from the sea anemone Radianthus macrodactylus with the use of chromatography on polytetrafluoroethylene, CM-Sephadex C-25 and by cation and anion exchange HPLC. The toxin was identified as palytoxin by u.v.-, i.r.- and 500 MHz 1H NMR spectroscopy. Its LD50 was 0.74 +/- 0.29 micrograms/kg by i.v. injection into mice. So far, palytoxin has been associated with zoanthids only. The toxin caused the loss of haemoglobin from erythrocytes but only in about 2 hr after the beginning of incubation, which is characteristic for palytoxin from zoanthids. Sea anemone palytoxin was divided into major and minor components by HPLC. The latter proved to be a product of degradation of palytoxin.

Respirable form of crystals of cromoglycic acid.

PubMed

Chan, H K; Gonda, I

1989-02-01

Respirable crystals of cromoglycic acid (CA) were prepared by precipitation of CA with hydrochloric acid from aqueous solutions of cromolyn sodium and subsequent recrystallization from hot water or mixtures of dimethyl sulphoxide and water. The properties of the materials were established by melting point measurements, UV, IR, and NMR spectroscopy, and X-ray diffraction. Aerosols of CA were generated by nebulization of dilute CA suspensions and drying. The aerodynamic size distribution of CA in the dried aerosols was found by cascade impaction, and could be characterized by a logarithmic normal function with a mass median aerodynamic diameter (MMAD) of 0.7 micron and geometric standard deviation (sigma g) of 1.9. The likely advantages and problems of CA aerosols in the prevention of asthma are discussed.

Molecular structure, spectral investigation (1H NMR, 13C NMR, UV-Visible, FT-IR, FT-Raman), NBO, intramolecular hydrogen bonding, chemical reactivity and first hyperpolarizability analysis of formononetin [7-hydroxy-3(4-methoxyphenyl)chromone]: A quantum chemical study

NASA Astrophysics Data System (ADS)

Srivastava, Anubha; Mishra, Rashmi; Kumar, Sudhir; Dev, Kapil; Tandon, Poonam; Maurya, Rakesh

2015-03-01

Formononetin [7-hydroxy-3(4-methoxyphenyl)chromone or 4‧-methoxy daidzein] is a soy isoflavonoid that is found abundantly in traditional Chinese medicine Astragalus mongholicus (Bunge) and Trifolium pretense L. (red clover), and in an Indian medicinal plant, Butea (B.) monosperma. Crude extract of B.monosperma is used for rapid healing of fracture in Indian traditional medicine. In this study, a combined theoretical and experimental approach is used to study the properties of formononetin. The optimized geometry was calculated by B3LYP method using 6-311++G(d,p) as a large basis set. The FT-Raman and FT-IR spectra were recorded in the solid phase, and interpreted in terms of potential energy distribution (PED) analysis. Density functional theory (DFT) is applied to explore the nonlinear optical properties of the molecule. Good consistency is found between the calculated results and observed data for the electronic absorption, IR and Raman spectra. The solvent effects have been calculated using time-dependent density functional theory in combination with the integral equation formalism polarized continuum model, and the results are in good agreement with observed measurements. The double well potential energy curve of the molecule about the respective bonds, have been plotted, as obtained from DFT/6-31G basis set. The computational results diagnose the most stable conformer of formononetin. The HOMO-LUMO energy gap of possible conformers has been calculated for comparing their chemical activity. Chemical reactivity has been measured by reactivity descriptors and molecular electrostatic potential surface (MEP). The 1H and 13C NMR chemical shifts of the molecule were calculated by the Gauge including atomic orbital (GIAO) method. Furthermore, the role of CHsbnd O intramolecular hydrogen bond in the stability of molecule is investigated on the basis of the results of topological properties of AIM theory and NBO analysis. The calculated first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics.

Infrared measurements on ultraviolet photolysis products at cryogenic temperatures

NASA Astrophysics Data System (ADS)

Dong, Weibing; He, Ping; Wang, Jessie; Zhou, Zhaohui; Wang, Hongxin

2013-01-01

Combination of ultraviolet (UV) photolysis with infrared (IR) spectroscopy (or UV/IR for abbreviation) is a powerful tool to study various chemical photoreactions, while cryostat and sample-cell windows define the working ranges for both UV and IR beams. Although diamond window has a very wide transmission range from UV to IR, the extreme cost, the absorptions at 1800-2600 cm-1 and other problems prevent it from being the solution for all cases. In this paper, a gas-exchange cryostat was modified to realize a UV/mid-IR experiment at cryogenic temperatures. Several windows (including diamond) were discussed as options. A di-nitrogen iron complex trans-[Fe(DMeOPrPE)2(N2)H][BPh4] [DMeOPrPE = 1,2-bis(dimethoxypropylphosphino)ethane] was studied as a real photolysis example. Alternatively, a cold-finger cryostat was modified for UV/far-IR compatible experiments. Non-photolysis samples K5[Mo4O11(R,S-Hhomocit)2]Cl·5H2O (H4homocit = homocitric acid) and [(n-Bu)4N]2[Fe4S4(PPh)4] were studied at cryogenic temperatures. Sample cell windows can also be used as a natural way for choosing photolysis wavelength (in addition to the use of optical filters).

Photochemical Degradation of the Anticancer Drug Bortezomib by V-UV/UV (185/254 nm) Investigated by (1)H NMR Fingerprinting: A Way to Follow Aromaticity Evolution.

PubMed

Martignac, Marion; Balayssac, Stéphane; Gilard, Véronique; Benoit-Marquié, Florence

2015-06-18

We have investigated the removal of bortezomib, an anticancer drug prescribed in multiple myeloma, using the photochemical advanced oxidation process of V-UV/UV (185/254 nm). We used two complementary analytical techniques to follow the removal rate of bortezomib. Nuclear magnetic resonance (NMR) is a nonselective method requiring no prior knowledge of the structures of the byproducts and permits us to provide a spectral signature (fingerprinting approach). This untargeted method provides clues to the molecular structure changes and information on the degradation of the parent drug during the irradiation process. This holistic NMR approach could provide information for monitoring aromaticity evolution. We use liquid chromatography, coupled with high-resolution mass spectrometry (LC-MS), to correlate results obtained by (1)H NMR and for accurate identification of the byproducts, in order to understand the mechanistic degradation pathways of bortezomib. The results show that primary byproducts come from photoassisted deboronation of bortezomib at 254 nm. A secondary byproduct of pyrazinecarboxamide was also identified. We obtained a reliable correlation between these two analytical techniques.

Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory

ERIC Educational Resources Information Center

Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

2012-01-01

This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

Determination of Diethyl Phthalate and Polyhexamethylene Guanidine in Surrogate Alcohol from Russia

PubMed Central

Monakhova, Yulia B.; Kuballa, Thomas; Leitz, Jenny; Lachenmeier, Dirk W.

2011-01-01

Analytical methods based on spectroscopic techniques were developed and validated for the determination of diethyl phthalate (DEP) and polyhexamethylene guanidine (PHMG), which may occur in unrecorded alcohol. Analysis for PHMG was based on UV-VIS spectrophotometry after derivatization with Eosin Y and 1H NMR spectroscopy of the DMSO extract. Analysis of DEP was performed with direct UV-VIS and 1H NMR methods. Multivariate curve resolution and spectra computation methods were used to confirm the presence of PHMG and DEP in the investigated beverages. Of 22 analysed alcohol samples, two contained DEP or PHMG. 1H NMR analysis also revealed the presence of signals of hawthorn extract in three medicinal alcohols used as surrogate alcohol. The simple and cheap UV-VIS methods can be used for rapid screening of surrogate alcohol samples for impurities, while 1H NMR is recommended for specific confirmatory analysis if required. PMID:21647285

Determination of diethyl phthalate and polyhexamethylene guanidine in surrogate alcohol from Russia.

PubMed

Monakhova, Yulia B; Kuballa, Thomas; Leitz, Jenny; Lachenmeier, Dirk W

2011-01-01

Analytical methods based on spectroscopic techniques were developed and validated for the determination of diethyl phthalate (DEP) and polyhexamethylene guanidine (PHMG), which may occur in unrecorded alcohol. Analysis for PHMG was based on UV-VIS spectrophotometry after derivatization with Eosin Y and (1)H NMR spectroscopy of the DMSO extract. Analysis of DEP was performed with direct UV-VIS and (1)H NMR methods. Multivariate curve resolution and spectra computation methods were used to confirm the presence of PHMG and DEP in the investigated beverages. Of 22 analysed alcohol samples, two contained DEP or PHMG. (1)H NMR analysis also revealed the presence of signals of hawthorn extract in three medicinal alcohols used as surrogate alcohol. The simple and cheap UV-VIS methods can be used for rapid screening of surrogate alcohol samples for impurities, while (1)H NMR is recommended for specific confirmatory analysis if required.

Combined In Situ Illumination-NMR-UV/Vis Spectroscopy: A New Mechanistic Tool in Photochemistry.

PubMed

Seegerer, Andreas; Nitschke, Philipp; Gschwind, Ruth M

2018-06-18

Synthetic applications in photochemistry are booming. Despite great progress in the development of new reactions, mechanistic investigations are still challenging. Therefore, we present a fully automated in situ combination of NMR spectroscopy, UV/Vis spectroscopy, and illumination to allow simultaneous and time-resolved detection of paramagnetic and diamagnetic species. This optical fiber-based setup enables the first acquisition of combined UV/Vis and NMR spectra in photocatalysis, as demonstrated on a conPET process. Furthermore, the broad applicability of combined UVNMR spectroscopy for light-induced processes is demonstrated on a structural and quantitative analysis of a photoswitch, including rate modulation and stabilization of transient species by temperature variation. Owing to the flexibility regarding the NMR hardware, temperature, and light sources, we expect wide-ranging applications of this setup in various research fields. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Chemical behavior of methylpyranomalvidin-3-O-glucoside in aqueous solution studied by NMR and UV-visible spectroscopy.

PubMed

Oliveira, Joana; Petrov, Vesselin; Parola, A Jorge; Pina, Fernando; Azevedo, Joana; Teixeira, Natércia; Brás, Natércia F; Fernandes, Pedro A; Mateus, Nuno; Ramos, Maria João; de Freitas, Victor

2011-02-17

In the present work, the proton-transfer reactions of the methylpyranomalvidin-3-O-glucoside pigment in water with different pH values was studied by NMR and UV-visible spectroscopies. The results showed four equilibrium forms: the methylpyranomalvidin-3-O-glucoside cation, the neutral quinoidal base, the respective anionic quinoidal base, and a dianionic base unprotonated at the methyl group. According to the NMR data, it seems that for methylpyranomalvidin-3-O-glucoside besides the acid-base equilibrium between the pyranoflavylium cation and the neutral quinoidal base, a new species is formed at pD 4.88-6.10. This is corroborated by the appearance of a new set of signals in the NMR spectrum that may be assigned to the formation of hemiketal/cis-chalcone species to a small extent. The two ionization constants (pK(a1) and pK(a2)) obtained by both methods (NMR and UV-visible) for methylpyranomalvidin-3-O-glucoside are in agreement (pK(a1) = 5.17 ± 0.03; pK(a2) = 8.85 ± 0.08; and pK(a1) = 4.57 ± 0.07; pK(a2) = 8.23 ± 0.04 obtained by NMR and UV-visible spectroscopies, respectively). Moreover, the fully dianionic unprotonated form (at the methyl group) of the methylpyranomalvidin-3-O-glucoside is converted slowly into a new structure that displays a yellow color at basic pH. On the basis of the results obtained through LC-MS and NMR, the proposed structure was found to correspond to the flavonol syringetin-3-glucoside.

Structural, spectral, DFT and biological studies on macrocyclic mononuclear ruthenium (II) complexes

NASA Astrophysics Data System (ADS)

Muthukkumar, M.; Kamal, C.; Venkatesh, G.; Kaya, C.; Kaya, S.; Enoch, Israel V. M. V.; Vennila, P.; Rajavel, R.

2017-11-01

Macrocyclic mononuclear ruthenium (II) complexes have been synthesized by condensation method [Ru (L1, L2, L3) Cl2] L1 = (C36 H31 N9), L2= (C42H36N8), L3= (C32H32 N8)]. These ruthenium complexes have been established by elemental analyses and spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR), 1H- nuclear magnetic resonance (NMR), 13C- NMR and Electrospray ionization mass spectrometry (ESI-MS)). The coordination mode of the ligand has been confirmed and the octahedral geometry around the ruthenium ion has been revealed. Binding affinity and binding mode of ruthenium (II) complexes with Bovine serum Albumin (BSA) have been characterized by Emission spectra analysis. UV-Visible and fluorescence spectroscopic techniques have also been utilized to examine the interaction between ligand and its complexes L1, L2, & L3 with BSA. Chemical parameters and molecular structure of Ru (II) complexes L1H, L2H, & L3H have been determined by DFT coupled with B3LYP/6-311G** functional in both the gaseous and aqueous phases.

[Simultaneous isolation and purification of gallic acid and brevifolincarboxylic acid from Polygonum capitatum by high-speed counter-current chromatography].

PubMed

Chen, Xinxia; Zhang, Liyan; Wan, Jinzhi; Liang, Bin; Xie, Yu

2010-08-01

To isolate and purify gallic acid and brevifolincarboxylic acid simultaneously by high-speed counter-current chromatography (HSCCC) from a crude extract of Polygonum capitatum. The biphasic solvent system composed of ethyl acetate-n-butanol-0.44% acetic acid (3:1:5) was used at a flow rate of 2.0 mL x min(-1), while the aqueous phase was selected as the mobile phase and the apparatus was rotated at 860 r x min(-1). The effluent was detected at 272 nm. 51.5 mg of gallic acid and 5.9 mg of brevifolincarboxylic acid were separated from 1.07 g of the crude extract with the purities of 99.7% and 97.5%, respectively, while brevifolincarboxylic acid was obtained firstly from the genus Polygonum. The structures of the compounds were identified by ultraviolet spectrometry (UV), infra-red spectrometry (IR), liquid chromatography/mass spectrometry (LC/MS), time-of-flight mass spectrometry( TOF-MS), 1H-nuclear magnetic resonance (NMR) and 13C-NMR. This method is feasible and rapid for isolation and purification of gallice acid and brevifolincarboxylil acid.

Cytotoxic halogenated monoterpenes from Plocamium cartilagineum.

PubMed

Sabry, Omar M M; Goeger, Douglas E; Valeriote, Frederick A; Gerwick, William H

2017-02-01

As a result of our efforts to identify bioactive agents from marine algae, we have isolated and identified one new halogenated monoterpene 1 [(-)-(5E,7Z)-348-trichloro-7-dichloromethyl-3-methyl-157-octatriene] in addition to three known compounds (2, 3 and 4) from the red alga Plocamium cartilagineum collected by hand from the eastern coast of South Africa. Compound 1 was found to be active as a cytotoxic agent in human lung cancer (NCI-H460) and mouse neuro-2a cell lines (IC 50 4 μg/mL). Two of these compounds (3 and 4) were found to have cytotoxic activity in other cell line assays, especially against human leukaemia and human colon cancers (IC 50 1.3 μg/mL). None of these metabolites were active as sodium channel blockers or activators. All structures were determined by spectroscopic methods (UV, IR, LRMS, HRMS, 1D NMR and 2D NMR). 1D and 2D NOE experiments were carried out on these compounds to confirm the geometry of the double bonds.

Growth, density functional theory (DFT) and spectral studies on L-2-aminobutyric acid -biologically active material

NASA Astrophysics Data System (ADS)

Usha, C.; Santhakumari, R.; Meenakshi, R.; Jayasree, R.; Bhuvaneswari, M.

2017-12-01

Single crystal of L-2-aminobutyric acid (ABA) was grown from water by slow evaporation at room temperature. The crystalline nature of the grown crystal was confirmed using powder X-ray diffraction studies. The grown crystal was subjected to FT-IR, FT-Raman, 1H NMR and 13C NMR spectral analyses to confirm the presence of functional group and molecular structure respectively. Thermal properties were investigated by thermogravimetric and differential thermal analyses. The range and percentage of optical transmission was ascertained by recording UV-vis-NIR spectrum. The electronic charge distribution and reactivity of the molecules within the crystal were studied by HOMO and LUMO analysis and the molecular electrostatic potential (MEP) of the grown crystal was performed using the B3LYP method. The anti-bacterial activities of the crystal were performed by disk diffusion method against the standard bacteria E. coli. The crystal exhibits good anti-bacterial activity. Second harmonic generation efficiency of the powdered ABA crystal was tested using Nd:YAG laser and it is found to be ∼3.3 times that of potassium dihydrogen orthophosphate.

DNA cleavage, antibacterial, antifungal and anthelmintic studies of Co(II), Ni(II) and Cu(II) complexes of coumarin Schiff bases: Synthesis and spectral approach

NASA Astrophysics Data System (ADS)

Patil, Sangamesh A.; Prabhakara, Chetan T.; Halasangi, Bhimashankar M.; Toragalmath, Shivakumar S.; Badami, Prema S.

2015-02-01

The metal complexes of Co(II), Ni(II) and Cu(II) have been synthesized from 6-formyl-7,8-dihydroxy-4-methylcoumarin with o-toluidine/3-aminobenzotrifluoride. The synthesized Schiff bases and their metal complexes were structurally characterized based on IR, 1H NMR, 13C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The molar conductance values indicate that complexes are non-electrolytic in nature. Elemental analysis reveals ML2·2H2O [M = Co(II), Ni(II) and Cu(II)] stoichiometry, where 'L' stands for a singly deprotonated ligand. The presence of co-ordinated water molecules were confirmed by thermal studies. The spectroscopic studies suggest the octahedral geometry. Redox behavior of the complexes were confirmed by cyclic voltammetry. All the synthesized compounds were screened for their antibacterial (Escherichia coli, Pseudomonas auregenosa, klebsiella, Proteus, Staphylococcus aureus and salmonella) antifungal (Candida, Aspergillus niger and Rhizopus), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activity.

Novel axially disubstituted non-aggregated silicon phthalocyanines.

PubMed

Bıyıklıoğlu, Zekeriya; Cakır, Dilek

2012-12-01

This paper describes the synthesis, spectroscopic characterization of a range of new axially-disubstituted silicon phthalocyanines with 2-[2-(dimethylamino)ethoxy] or 2-[2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)ethoxy] groups as axial ligands. 2-[2-(Dimethylamino)ethoxy]ethanol 2, 2-[2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)ethoxy]ethanol 4 are reacted with silicon phthalocyanine 1, to give an axially-disubstituted silicon phthalocyanines 3 and 5. Axially-disubstituted silicon phthalocyanine complexes were synthesized at the first time. Newly synthesized silicon phthalocyanines were characterized by UV-Vis, IR, (1)H NMR, (13)C NMR spectroscopy, ESI mass spectrometry. These new silicon(IV) phthalocyanines 3 and 5 showed excellent solubility in organic solvents such as CHCl(3), CH(2)Cl(2), acetone, DMF, DMSO, THF, EtOAc. The aggregation behavior of these compounds were investigated in different concentrations of DMSO. The effect of solvents on absorption spectra were studied in various organic solvents. The thermal stabilities of the silicon(IV) phthalocyanines 3 and 5 were determined by thermogravimetric analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Mononuclear Pd(II) complex as a new therapeutic agent: Synthesis, characterization, biological activity, spectral and DNA binding approaches

NASA Astrophysics Data System (ADS)

Saeidifar, Maryam; Mirzaei, Hamidreza; Ahmadi Nasab, Navid; Mansouri-Torshizi, Hassan

2017-11-01

The binding ability between a new water-soluble palladium(II) complex [Pd(bpy)(bez-dtc)]Cl (where bpy is 2,2‧-bipyridine and bez-dtc is benzyl dithiocarbamate), as an antitumor agent, and calf thymus DNA was evaluated using various physicochemical methods, such as UV-Vis absorption, Competitive fluorescence studies, viscosity measurement, zeta potential and circular dichroism (CD) spectroscopy. The Pd(II) complex was synthesized and characterized using elemental analysis, molar conductivity measurements, FT-IR, 1H NMR, 13C NMR and electronic spectra studies. The anticancer activity against HeLa cell lines demonstrated lower cytotoxicity than cisplatin. The binding constants and the thermodynamic parameters were determined at different temperatures (300 K, 310 K and 320 K) and shown that the complex can bind to DNA via electrostatic forces. Furthermore, this result was confirmed by the viscosity and zeta potential measurements. The CD spectral results demonstrated that the binding of Pd(II) complex to DNA induced conformational changes in DNA. We hope that these results will provide a basis for further studies and practical clinical use of anticancer drugs.

DNA cleavage, antibacterial, antifungal and anthelmintic studies of Co(II), Ni(II) and Cu(II) complexes of coumarin Schiff bases: synthesis and spectral approach.

PubMed

Patil, Sangamesh A; Prabhakara, Chetan T; Halasangi, Bhimashankar M; Toragalmath, Shivakumar S; Badami, Prema S

2015-02-25

The metal complexes of Co(II), Ni(II) and Cu(II) have been synthesized from 6-formyl-7,8-dihydroxy-4-methylcoumarin with o-toluidine/3-aminobenzotrifluoride. The synthesized Schiff bases and their metal complexes were structurally characterized based on IR, (1)H NMR, (13)C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The molar conductance values indicate that complexes are non-electrolytic in nature. Elemental analysis reveals ML2·2H2O [M = Co(II), Ni(II) and Cu(II)] stoichiometry, where 'L' stands for a singly deprotonated ligand. The presence of co-ordinated water molecules were confirmed by thermal studies. The spectroscopic studies suggest the octahedral geometry. Redox behavior of the complexes were confirmed by cyclic voltammetry. All the synthesized compounds were screened for their antibacterial (Escherichia coli, Pseudomonas auregenosa, klebsiella, Proteus, Staphylococcus aureus and salmonella) antifungal (Candida, Aspergillus niger and Rhizopus), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Microplate assay for screening the antibacterial activity of Schiff bases derived from substituted benzopyran-4-one.

PubMed

Amin, Rehab M; Abdel-Kader, Nora S; El-Ansary, Aida L

2012-09-01

Schiff bases (SB(1)-SB(3)) were synthesized from the condensation of 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one with 2-aminopyridine (SB(1)), p-phenylenediamine (SB(2)) and o-phenylenediamine (SB(3)), while Schiff bases (SB(4)-SB(6)) were synthesized by condensation of 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one with 2-aminopyridine (SB(4)), p-phenylenediamine (SB(5)) and o-phenylenediamine (SB(6)). Schiff bases were characterized using elemental analysis, IR, UV-Vis, (1)H NMR, (13)C NMR and mass spectroscopy. These compounds were screened for antibacterial activities by micro-plate assay technique. Escherichia coli and Staphylococcus capitis were exposed to different concentrations of the Schiff bases. Results showed that the antibacterial effect of these Schiff bases on Gram-negative bacteria were higher than that on Gram-positive bacteria moreover, the Schiff bases containing substituent OCH(3) on position five have higher antibacterial activity than that containing hydroxy group on the same position. Copyright © 2012 Elsevier B.V. All rights reserved.

Experimental and theoretical characterization of organic salt: 2-((4-bromophenyl)amino) pyrido[1,2-a] quinoxalin-11-ium bromide monohydrate synthesized via oxidative cyclization

NASA Astrophysics Data System (ADS)

Faizi, Md. Serajul Haque; Alam, Mohammad Jane; Haque, Ashanul; Ahmad, Shabbir; Shahid, M.; Ahmad, Musheer

2018-03-01

Quinoxalines are nitrogen-embedded heterocyclic compounds that possess unique and versatile pharmacological applications. The present article describes synthesis and characterization of organic salt 2-((4-bromophenyl)amino)pyrido [1,2-a]quinoxalin-11-ium bromide (BAPQ), an oxidative cyclized product of N-phenyl-N-(pyridine-2-ylmethylene)benzene-1,4-diamine (PPMD). The structure of the synthesized product was extensively characterized by 1H NMR, 2D-COSY NMR, MS, IR, UV-vis, X-ray techniques and elemental analysis. The electronic and structural properties of BAPQ was well complemented by performing extensive computational studies (B3LYP/6-311G (d,p) basis sets). Metal-free, mild reaction condition, easy work-up and excellent yield with high purity are main features of this work and thus holds promise for the generation of new compounds of this class. Analytical results indicated ionic nature of the compound with bromide as counterion. DFT calculation showed low kinetic stability and high reactivity of the compound.

Mono azo dyes derived from 5-nitroanthranilic acid: Synthesis, absorption properties and DFT calculations

NASA Astrophysics Data System (ADS)

Karabacak Atay, Çiğdem; Gökalp, Merve; Kart, Sevgi Özdemir; Tilki, Tahir

2017-08-01

Four new azo dyes: 2-[(3,5-diamino-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (A), 2-[(3-hydroxy-5-methyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (B), 2-[(3,5-dimethyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (C) and 2-[(5-amino-3-methyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (D) which have the same 4-nitrobenzene/azo/pyrazole skeleton and different substituted groups are synthesized in this work. The structures and spectroscopic properties of these new azo dyes are characterized by using spectroscopic methods such as FT-IR, 1H NMR, 13C NMR and UV-vis. Their solvatochromic properties in chloroform, acetic acid, methanol, dimethylformamide (DMF) and dimethylsulphoxide (DMSO) are studied. Moreover, molecular structures and some spectroscopic properties of azo dyes are investigated by utilizing the quantum computational chemistry method based on Density Functional Theory (DFT) employing B3LYP hybrid functional level with 6-31G(d) basis set. It is seen that experimental and theoretical results are compatible with each other.

The spectroscopic properties of anticancer drug Apigenin investigated by using DFT calculations, FT-IR, FT-Raman and NMR analysis

NASA Astrophysics Data System (ADS)

Mariappan, G.; Sundaraganesan, N.; Manoharan, S.

2012-09-01

The FT-Raman and FT-Infrared spectra of solid Apigenin sample were measured in order to elucidate the spectroscopic properties of title molecule in the spectral range of 3500-50 cm-1 and 4000-400 cm-1, respectively. The recorded FT-IR and FT-Raman spectral measurements favor the calculated (by B3LYP/6-31G(d,p) method) structural parameters which are further supported by spectral simulation. Additional support is given by the collected 1H and 13C NMR spectra recorded with the sample dissolved in DMSO. The predicted chemical shifts at the B3LYP/6-31G(d) level obtained using the Gauge-Invariant Atomic Orbitals (GIAO) method with and without inclusion of solvent using the Polarizable Continuum Model (PCM). By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. The UV-visible absorption spectra of the compound that dissolved in Ethanol, Methanol and DMSO were recorded in the range of 800-200 nm. The formation of hydrogen bond and the most possible interaction are explained using natural bond orbital (NBO) analysis. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and atomic charges of the title compound were investigated using theoretical calculations. The results are discussed herein and compared with similar molecules whenever appropriate.

Quantum mechanical, spectroscopic studies (FT-IR, FT-Raman, NMR, UV) and normal coordinates analysis on 3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide

NASA Astrophysics Data System (ADS)

Muthu, S.; Uma Maheswari, J.; Sundius, Tom

2013-05-01

Famotidine (3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide) is a histamine H2-receptor antagonist that inhibits stomach acid production, and it is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). Quantum chemical calculations of the equilibrium geometry of famotidine in the ground state were carried out using density functional theory (DFT/B3LYP) with the 6-311G(d,p) basis set. In addition, harmonic vibrational frequencies, infrared intensities and Raman activities were calculated at the same level of theory. A detailed interpretation of the infrared and Raman spectrum of the drug is also reported. Theoretical simulations of the FT-IR, and FT-Raman spectra of the title compound have been calculated. Good correlations between the experimental 1H and 13C NMR chemical shifts and calculated GIAO shielding tensors were found. The results of the energy and oscillator strength calculations by time-dependent density functional theory (TD-DFT) supplement the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials.

Synthesis, X-ray crystallography, spectroscopic (FT-IR, 1H &13C NMR and UV), computational (DFT/B3LYP) and enzymes inhibitory studies of 7-hydroximinocholest-5-en-3-ol acetate

NASA Astrophysics Data System (ADS)

Ahmad, Faheem; Parveen, Mehtab; Alam, Mahboob; Azaz, Shaista; Malla, Ali Mohammed; Alam, Mohammad Jane; Lee, Dong-Ung; Ahmad, Shabbir

2016-07-01

The present study reports the synthesis of 7-Hydroximinocholest-5-en-3-ol acetate (syn. 3β-acetoxycholest-5-en-7-one oxime; in general, steroidal oxime). The identity of steroidal molecule was confirmed by NMR, FT-IR, MS, CHN microanalysis and X-ray crystallography. DFT calculations on the titled molecule have been performed. The molecular structure and spectra interpreted by Gaussian hybrid computational analysis theory (B3LYP) are found to be in good correlation with the experimental data obtained from the various spectrophotometric techniques. The vibrational bands appearing in the FTIR are assigned with great accuracy using harmonic frequencies along with intensities and animated modes. Molecular properties like HOMO-LUMO analysis, chemical reactivity descriptors, MEP mapping, dipole moment and natural atomic charges have been presented at the same level of theory. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The percentages of various interactions are pictorialized by fingerprint plots of Hirshfeld surface. Steroidal oxime exhibited promising inhibitory activity against acetylcholinesterase (AChE) as compared to the reference drug, tacrine. Molecular docking was performed to introduce steroidal molecules into the X-ray crystal structures of acetylcholinesterase at the active site to find out the probable binding mode. The results of molecular docking admitted that steroidal oxime may exhibit enzyme inhibitor activity.

A Study on Spectro-Analytical Aspects, DNA - Interaction, Photo-Cleavage, Radical Scavenging, Cytotoxic Activities, Antibacterial and Docking Properties of 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione and its Metal Complexes.

PubMed

Ravi, Mudavath; Chennam, Kishan Prasad; Ushaiah, B; Eslavath, Ravi Kumar; Perugu, Shyam; Ajumeera, Rajanna; Devi, Ch Sarala

2015-09-01

The focus of the present work is on the design, synthesis, characterization, DNA-interaction, photo-cleavage, radical scavenging, in-vitro cytotoxicity, antimicrobial, docking and kinetic studies of Cu (II), Cd (II), Ce (IV) and Zr (IV) metal complexes of an imine derivative, 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione. The investigation of metal ligand interactions for the determination of composition of metal complexes, corresponding kinetic studies and antioxidant activity in solution was carried out by spectrophotometric methods. The synthesized metal complexes were characterized by EDX analysis, Mass, IR, (1)H-NMR, (13)C-NMR and UV-Visible spectra. DNA binding studies of metal complexes with Calf thymus (CT) DNA were carried out at room temperature by employing UV-Vis electron absorption, fluorescence emission and viscosity measurement techniques. The results revealed that these complexes interact with DNA through intercalation. The results of in vitro antibacterial studies showed the enhanced activity of chelating agent in metal chelated form and thus inferring scope for further development of new therapeutic drugs. Cell viability experiments indicated that all complexes showed significant dose dependent cytotoxicity in selected cell lines. The molecular modeling and docking studies were carried out with energy minimized structures of metal complexes to identify the receptor to metal interactions.

Discrimination of Aurantii Fructus Immaturus and Fructus Poniciri Trifoliatae Immaturus by Flow Injection UV Spectroscopy (FIUV) and 1H NMR using Partial Least-squares Discriminant Analysis (PLS-DA)

USDA-ARS?s Scientific Manuscript database

Two simple fingerprinting methods, flow-injection UV spectroscopy (FIUV) and 1H nuclear magnetic resonance (NMR), for discrimination of Aurantii FructusImmaturus and Fructus Poniciri TrifoliataeImmaturususing were described. Both methods were combined with partial least-squares discriminant analysis...

NMR and IR Spectroscopy for the Structural Characterization of Edible Fats and Oils: An Instrumental Analysis Laboratory

ERIC Educational Resources Information Center

Crowther, Molly W.

2008-01-01

This article describes an upper-level instrumental laboratory for undergraduates that explores the complementary nature of IR and NMR spectroscopy for analysis of several edible fats and oils that are structurally similar but differ in physical properties and health implications. Five different fats and oils are analyzed for average chain length,…

Evaluation of State-of-the-Art High Speed Deluge Systems Presently in Service at Various U.S. Army Ammunition Plants

DTIC Science & Technology

1993-09-01

designed to respond to. No data exists on spectral irradiances in the IR or UV spectral bands where the current detectors operate. A need exists to...appropriate fire/explosion detection spectral bands. Setting a pyrotechnic fire and testing the responses of commercial UV and IR detectors that are designed...PNZ B. DETECTOR BACKGROUND ............... 30 C. UV DETECTORS . . ............ . . . 32 D. IR DETECTORS . . . ......... . . ... 34 E. MACHINE VISION

Towards universal hybrid star formation rate estimators

NASA Astrophysics Data System (ADS)

Boquien, M.; Kennicutt, R.; Calzetti, D.; Dale, D.; Galametz, M.; Sauvage, M.; Croxall, K.; Draine, B.; Kirkpatrick, A.; Kumari, N.; Hunt, L.; De Looze, I.; Pellegrini, E.; Relaño, M.; Smith, J.-D.; Tabatabaei, F.

2016-06-01

Context. To compute the star formation rate (SFR) of galaxies from the rest-frame ultraviolet (UV), it is essential to take the obscuration by dust into account. To do so, one of the most popular methods consists in combining the UV with the emission from the dust itself in the infrared (IR). Yet, different studies have derived different estimators, showing that no such hybrid estimator is truly universal. Aims: In this paper we aim at understanding and quantifying what physical processes fundamentally drive the variations between different hybrid estimators. In so doing, we aim at deriving new universal UV+IR hybrid estimators to correct the UV for dust attenuation at local and global scales, taking the intrinsic physical properties of galaxies into account. Methods: We use the CIGALE code to model the spatially resolved far-UV to far-IR spectral energy distributions of eight nearby star-forming galaxies drawn from the KINGFISH sample. This allows us to determine their local physical properties, and in particular their UV attenuation, average SFR, average specific SFR (sSFR), and their stellar mass. We then examine how hybrid estimators depend on said properties. Results: We find that hybrid UV+IR estimators strongly depend on the stellar mass surface density (in particular at 70 μm and 100 μm) and on the sSFR (in particular at 24 μm and the total infrared). Consequently, the IR scaling coefficients for UV obscuration can vary by almost an order of magnitude: from 1.55 to 13.45 at 24 μm for instance. This result contrasts with other groups who found relatively constant coefficients with small deviations. We exploit these variations to construct a new class of adaptative hybrid estimators based on observed UV to near-IR colours and near-IR luminosity densities per unit area. We find that they can reliably be extended to entire galaxies. Conclusions: The new estimators provide better estimates of attenuation-corrected UV emission than classical hybrid estimators published in the literature. Taking naturally variable impact of dust heated by old stellar populations into account, they constitute an important step towards universal estimators.

Comparison of Attenuated Total Reflectance Mid-Infrared, Near Infrared, and 1H-Nuclear Magnetic Resonance Spectroscopies for the Determination of Coffee's Geographical Origin.

PubMed

Medina, Jessica; Caro Rodríguez, Diana; Arana, Victoria A; Bernal, Andrés; Esseiva, Pierre; Wist, Julien

2017-01-01

The sensorial properties of Colombian coffee are renowned worldwide, which is reflected in its market value. This raises the threat of fraud by adulteration using coffee grains from other countries, thus creating a demand for robust and cost-effective methods for the determination of geographical origin of coffee samples. Spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), near infrared (NIR), and mid-infrared (mIR) have arisen as strong candidates for the task. Although a body of work exists that reports on their individual performances, a faithful comparison has not been established yet. We evaluated the performance of 1 H-NMR, Attenuated Total Reflectance mIR (ATR-mIR), and NIR applied to fraud detection in Colombian coffee. For each technique, we built classification models for discrimination by species ( C. arabica versus C. canephora (or robusta )) and by origin (Colombia versus other C. arabica ) using a common set of coffee samples. All techniques successfully discriminated samples by species, as expected. Regarding origin determination, ATR-mIR and 1 H-NMR showed comparable capacity to discriminate Colombian coffee samples, while NIR fell short by comparison. In conclusion, ATR-mIR, a less common technique in the field of coffee adulteration and fraud detection, emerges as a strong candidate, faster and with lower cost compared to 1 H-NMR and more discriminating compared to NIR.

Airborne pipeline leak detection: UV or IR?

NASA Astrophysics Data System (ADS)

Babin, François; Gravel, Jean-François; Allard, Martin

2016-05-01

This paper presents a study of different approaches to the measurement of the above ground vapor plume created by the spill caused by a small 0.1 l/min (or less) leak in an underground liquid petroleum pipeline. The scenarios are those for the measurement from an airborne platform. The usual approach is that of IR absorption, but in the case of liquid petroleum products, there are drawbacks that will be discussed, especially when using alkanes to detect a leak. The optical measurements studied include UV enhanced Raman lidar, UV fluorescence lidar and IR absorption path integrated lidars. The breadboards used for testing the different approaches will be described along with the set-ups for leak simulation. Although IR absorption would intuitively be the most sensitive, it is shown that UV-Raman could be an alternative. When using the very broad alkane signature in the IR, the varying ground spectral reflectance are a problem. It is also determined that integrated path measurements are preferred, the UV enhanced Raman measurements showing that the vapor plume stays very close to the ground.

Simultaneous infrared and UV-visible absorption spectra of matrix-isolated carbon vapor

NASA Technical Reports Server (NTRS)

Kurtz, Joe; Huffman, Donald R.

1989-01-01

Carbon molecules were suggested as possible carriers of the diffuse interstellar bands. In particular, it was proposed that the 443 nm diffuse interstellar band is due to the same molecule which gives rise to the 447 nm absorption feature in argon matrix-isolated carbon vapor. If so, then an associated C-C stretching mode should be seen in the IR. By doing spectroscopy in both the IR and UV-visible regions on the same sample, the present work provides evidence for correlating UV-visible absorption features with those found in the IR. Early data indicates no correlation between the strongest IR feature (1997/cm) and the 447 nm band. Correlation with weaker IR features is being investigated.

Spectroscopic (FT-IR, FT-Raman, NMR and UV-Visible) and quantum chemical studies of molecular geometry, Frontier molecular orbital, NLO, NBO and thermodynamic properties of salicylic acid.

PubMed

Suresh, S; Gunasekaran, S; Srinivasan, S

2014-11-11

The solid phase FT-IR and FT-Raman spectra of 2-hydroxybenzoic acid (salicylic acid) have been recorded in the region 4000-400 and 4000-100 cm(-1) respectively. The optimized molecular geometry and fundamental vibrational frequencies are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) method and a comparative study between Hartree Fork (HF) method at 6-311++G(d,p) level basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimentally obtained FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated potential energy distribution (PED). The time dependent DFT method is employed to predict its absorption energy and oscillator strength. The linear polarizability (α) and the first order hyper polarizability (β) values of the investigated molecule have been computed. The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) are also performed. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Published by Elsevier B.V.

Distorted tetrahedral nickel-nitrosyl complexes: spectroscopic characterization and electronic structure.

PubMed

Soma, Shoko; Van Stappen, Casey; Kiss, Mercedesz; Szilagyi, Robert K; Lehnert, Nicolai; Fujisawa, Kiyoshi

2016-09-01

The linear nickel-nitrosyl complex [Ni(NO)(L3)] supported by a highly hindered tridentate nitrogen-based ligand, hydrotris(3-tertiary butyl-5-isopropyl-1-pyrazolyl)borate (denoted as L3), was prepared by the reaction of the potassium salt of the ligand with the nickel-nitrosyl precursor [Ni(NO)(Br)(PPh 3 ) 2 ]. The obtained nitrosyl complexes as well as the corresponding chlorido complexes [Ni(NO)(Cl)(PPh 3 ) 2 ] and [Ni(Cl)(L3)] were characterized by X-ray crystallography and different spectroscopic methods including IR/far-IR, UV-Vis, NMR, and multi-edge X-ray absorption spectroscopy at the Ni K-, Ni L-, Cl K-, and P K-edges. For comparative electronic structure analysis we also performed DFT calculations to further elucidate the electronic structure of [Ni(NO)(L3)]. These results provide the nickel oxidation state and the character of the Ni-NO bond. The complex [Ni(NO)(L3)] is best described as [Ni (II) (NO (-) )(L3)], and the spectroscopic results indicate that the phosphane complexes have a similar [Ni (II) (NO (-) )(X)(PPh 3 ) 2 ] ground state.

Synthesis, spectroscopic, thermal and antimicrobial studies of neodymium(III) and samarium(III) complexes derived from tetradentate ligands containing N and S donor atoms

NASA Astrophysics Data System (ADS)

Ain, Qurratul; Pandey, S. K.; Pandey, O. P.; Sengupta, S. K.

2015-04-01

Trivalent lanthanide complexes of the type [Ln(L)Cl(H2O)2] (where Ln = Nd(III) or Sm(III) and LH2 = Schiff bases derived by the condensation of 3-(phenyl/substitutedphenyl)-4-amino-5-mercapto-1,2,4-triazole with diacetyl/benzil) have been synthesized by the reactions of anhydrous lanthanide(III) chloride with Schiff bases in methanol. The structures of the complexes have been proposed on the basis of elemental analysis, electrical conductance, magnetic moment, spectroscopic measurements (IR, 1H, 13C NMR and UV-vis spectra) and X-ray diffraction studies. The spectral data reveal that the Schiff base ligands behave as dibasic tetradentate chelating agents having coordination sites at two thiol sulfur atoms and two azomethine nitrogen atoms. The presence of coordinated water in metal complexes was confirmed by thermal and IR data of the complexes. All the Schiff bases and their metal complexes have also been screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus and antifungal activities against Aspergillus niger, Curvularia pallescens and Colletotrichum capsici.

Experimental, DFT and molecular docking studies on 2-(2-mercaptophenylimino)-4-methyl-2H-chromen-7-ol

NASA Astrophysics Data System (ADS)

Singh, Ashok Kumar; Singh, Ravindra Kumar

2016-10-01

A new coumarin derivative 2-(2-mercaptophenylimino)-4-methyl-2H-chromen-7-ol (COMSB) was synthesized and characterized with the help of 1H,13C NMR, FT-IR, FT-Raman and mass spectrometry. All quantum calculations were performed at DFT level of theory using B3LYP functional and 6-31G (d,p) as basis set. The UV-Vis spectrum studied by TD-DFT theory, with a hybrid exchange-correlation functional using Coulomb-attenuating method (CAM-B3LYP) in solvent phase gives similar pattern of bands, at energies and is consistent with that of experimental findings. The detailed analysis of vibrational (IR and Raman) spectra and their assignments has been done by computing Potential Energy Distribution (PED) using Gar2ped. Intra-molecular interactions were analyzed by 'Atoms in molecule' (AIM) approach. Computed first static hyperpolarizability (β0 = 8.583 × 10-30 esu) indicates non-linear optical (NLO) response of the molecule. Molecular docking studies show that the title molecule may act as potential acetylcholine esterase (AChE) inhibitor.

Spectroscopic, Electrochemical and DFT Studies of Phosphorescent Homoleptic Cyclometalated Iridium(III) Complexes Based on Substituted 4-Fluorophenylvinyl- and 4-Methoxyphenylvinylquinolines

PubMed Central

Adeloye, Adewale O.; Adekunle, Abolanle S.; Ramasami, Ponnadurai

2017-01-01

This study reports the synthesis and comparative investigation of the substituent effects of a new series of highly luminescent homoleptic tris-cyclometalated iridium(III) complexes of the type [Ir(N˄C)3]. These are based on two ligand type derivatives comprising of 4-fluorophenylvinylquinolines and 4-methoxyphenylvinylquinolines with electron-donating and/or electron-withdrawing groups as aryl substituents at 2-position. The structures of the ligands and their complexes were characterized by means of FT-IR, UV-Vis and NMR spectrometry complemented with photoluminescence and cyclic voltammetry. The photophysical properties of 2-aryl-4-(4-fluorophenylvinyl)quinoline and its corresponding complex were also studied using the density functional theory method. The photoluminescent properties of the ligands and the corresponding complexes showed high fluorescent intensities and quantum yields in solvents of different polarities. The photoluminescence spectra of the complexes in solid film, showed common transmission curves at longer wavelengths maximum (λem = 697 nm) possibly originating from the interference of scattered light of higher-order transmission of monochromators. PMID:28934145

Spectroscopic, Electrochemical and DFT Studies of Phosphorescent Homoleptic Cyclometalated Iridium(III) Complexes Based on Substituted 4-Fluorophenylvinyl- and 4-Methoxyphenylvinylquinolines.

PubMed

Adeloye, Adewale O; Mphahlele, Malose J; Adekunle, Abolanle S; Rhyman, Lydia; Ramasami, Ponnadurai

2017-09-21

This study reports the synthesis and comparative investigation of the substituent effects of a new series of highly luminescent homoleptic tris-cyclometalated iridium(III) complexes of the type [Ir(N ˄ C)₃]. These are based on two ligand type derivatives comprising of 4-fluorophenylvinylquinolines and 4-methoxyphenylvinylquinolines with electron-donating and/or electron-withdrawing groups as aryl substituents at 2-position. The structures of the ligands and their complexes were characterized by means of FT-IR, UV-Vis and NMR spectrometry complemented with photoluminescence and cyclic voltammetry. The photophysical properties of 2-aryl-4-(4-fluorophenylvinyl)quinoline and its corresponding complex were also studied using the density functional theory method. The photoluminescent properties of the ligands and the corresponding complexes showed high fluorescent intensities and quantum yields in solvents of different polarities. The photoluminescence spectra of the complexes in solid film, showed common transmission curves at longer wavelengths maximum (λ em = 697 nm) possibly originating from the interference of scattered light of higher-order transmission of monochromators.

One new and six known triterpene xylosides from Cimicifuga racemosa: FT-IR, Raman and NMR studies and DFT calculations

NASA Astrophysics Data System (ADS)

Jamróz, Marta K.; Jamróz, Michał H.; Cz. Dobrowolski, Jan; Gliński, Jan A.; Gleńsk, Michał

One new and six known triterpene xylosides were isolated from Cimicifuga racemosa (black cohosh, Actaea racemosa). The structure of a new compound, designated as isocimipodocarpaside (1), was established to be (24S)-3β-hydroxy-24,25-oxiirane-16,23-dione-9,10-seco-9,19-cyclolanost-1(10),7(8),9(11)-trien 3-O-β-D-xylopyranoside, by means of 1H and 13C NMR, IR and Raman spectroscopies and Mass Spectrometry. The six known compounds are: 23-epi-26-deoxycimicifugoside (2), 23-epi-26-deoxyactein (3), 25-anhydrocimigenol xyloside (4), 23-O-acetylshengmanol xyloside (5), 25-O-acetylcimigenol xyloside (6) and 3'-O-acetylcimicifugoside H-1 (7). On the basis of NMR data supported by DFT calculations of NMR shielding constants of (2), its structure, previously described as 26-deoxycimicifugoside was corrected and determined as 23-epi-26-deoxycimicifugoside. The 13C CPMAS NMR spectra of the studied compounds (1)-(7) provided data on their solid-state interactions. The IR and Raman spectra in the Cdbnd O, Cdbnd C, and Csbnd H stretching vibration regions clearly discriminate different triterpenes found in C. racemosa.

One new and six known triterpene xylosides from Cimicifuga racemosa: FT-IR, Raman and NMR studies and DFT calculations.

PubMed

Jamróz, Marta K; Jamróz, Michał H; Cz Dobrowolski, Jan; Gliński, Jan A; Gleńsk, Michał

2012-07-01

One new and six known triterpene xylosides were isolated from Cimicifuga racemosa (black cohosh, Actaea racemosa). The structure of a new compound, designated as isocimipodocarpaside (1), was established to be (24S)-3β-hydroxy-24,25-oxiirane-16,23-dione-9,10-seco-9,19-cyclolanost-1(10),7(8),9(11)-trien 3-O-β-d-xylopyranoside, by means of (1)H and (13)C NMR, IR and Raman spectroscopies and Mass Spectrometry. The six known compounds are: 23-epi-26-deoxycimicifugoside (2), 23-epi-26-deoxyactein (3), 25-anhydrocimigenol xyloside (4), 23-O-acetylshengmanol xyloside (5), 25-O-acetylcimigenol xyloside (6) and 3'-O-acetylcimicifugoside H-1 (7). On the basis of NMR data supported by DFT calculations of NMR shielding constants of (2), its structure, previously described as 26-deoxycimicifugoside was corrected and determined as 23-epi-26-deoxycimicifugoside. The (13)C CPMAS NMR spectra of the studied compounds (1)-(7) provided data on their solid-state interactions. The IR and Raman spectra in the CO, CC, and CH stretching vibration regions clearly discriminate different triterpenes found in C. racemosa. Copyright © 2012 Elsevier B.V. All rights reserved.

Examinations of the matrix isolation fourier transform infrared spectra of organic compounds: Part XII

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coleman, W. M., III; Gordon, B. M.; Lawrence, B. M.

1989-02-01

Matrix isolation Fourier transform infrared spectra (MI/FT-IR), massspectra (MS), carbon-13 Nuclear Magnetic Resonance (/sup 13/C-NMR) spectra,condensed-phase infrared spectra, and vapor-phase infrared (IR)spectra are presented for a series of terpene compounds. Subtle differencesin positional and configurational isomers commonly found withterpenes could be easily detected by the MI/FT-IR spectra. The resultsare comparable in some aspects to those obtainable from /sup 13/C-NMR andthin-film IR; however, most importantly, they are acquired at the lownanogram level for MI/FT-IR, as compared to the milligram level forthe other techniques. These results represent an advance in the technologyavailable for the analysis of complex mixtures such as essential oilscontainingmore » terpene-like molecules.« less

UV-Enhanced IR Raman System for Identifying Biohazards

NASA Technical Reports Server (NTRS)

Stirbl, Robert; Moynihan, Philip; Lane, Arthur

2003-01-01

An instrumentation system that would include an ultraviolet (UV) laser or light-emitting diode, an infrared (IR) laser, and the equivalent of an IR Raman spectrometer has been proposed to enable noncontact identification of hazardous biological agents and chemicals. In prior research, IR Raman scattering had shown promise as a means of such identification, except that the Raman-scattered light was often found to be too weak to be detected or to enable unambiguous identification in practical applications. The proposed system would utilize UV illumination as part of a two-level optical-pumping scheme to intensify the Raman signal sufficiently to enable positive identification.

Facile synthesis, structural elucidation and spectral analysis of pyrrole 4-imidazole derivatives

NASA Astrophysics Data System (ADS)

Singh, R. N.; Rawat, Poonam; Baboo, Vikas

2015-12-01

In this work pyrrole 4-imidazole derivatives (3A-3D): benzimidazoles and pyrrole 4-imidazoline have been synthesized by condensation, cyclization and oxidation of ethyl 4-formyl-3,5-dimethyl-1H-pyrrole carboxylate and phenylene diamine derivatives/ethylene diamine. The structure of these biheterocyclic compounds have been derived by elemental and spectroscopic - IR, UV, MS, 1H and 13C NMR analysis as well as theoretical study. The static first hyperpolarizability, β0 values for pyrrole 4-imidazole derivatives, (3A-3D) have been calculated as 10.901 × 10-31, 19.607 × 10-31, 40.323 × 10-31, 5.686 × 10-31 esu, respectively. The gradual increase in β0 value of synthesized pyrrole-benzimidazole derivatives from 3A to 3C is due to addition of acceptors -Cl atom in 3B to -NO2 group in 3C on benzimidazole side. The experimental absorption spectra found to be in UV region and the high β0 values show that the synthesized pyrrole-imidazoles are suitable as non-linear optical (NLO) materials.

Vibrational spectroscopic study, structural analysis, photophysical properties and theoretical calculations of cis-(±)-2,4,5-tris(pyridin-2-yl)imidazoline

NASA Astrophysics Data System (ADS)

Baldenebro-López, Jesús; Báez-Castro, Alberto; Glossman-Mitnik, Daniel; Höpfl, Herbert; Cruz-Enríquez, Adriana; Miranda-Soto, Valentín; Parra-Hake, Miguel; Campos-Gaxiola, José J.

2017-02-01

cis-(±)-2,4,5-tris(pyridin-2-yl)imidazoline has been fully characterized by FT-IR, FT-Raman, UV-Vis and fluorescence spectroscopy, one- and two-dimensional NMR spectroscopy (1H, 1H-1H gCOSY, 1H-1H gNOESY,13C{1H} ATP, 1H-13C and 1H-15N gHSQC and 1H-13C gHMBC), high-resolution mass spectrometry (HR-FAB+), TG-DSC analysis and low-temperature single-crystal X-ray diffraction analysis. Additionally, the molecular geometry and the vibrational infrared and Raman frequencies were calculated by density functional theory using the M06/6-31G(d) level of theory, showing good agreement with the experimental results. The title compound showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy and compared to the theoretically obtained parameters using TD-DFT calculations. Natural and Mulliken atomic charges and the molecular electrostatic potential (MEP) have been mapped.

Apoptosis mediated anti-proliferative effect of compound isolated from Cassia auriculata leaves against human colon cancer cell line

NASA Astrophysics Data System (ADS)

Esakkirajan, M.; Prabhu, N. M.; Manikandan, R.; Beulaja, M.; Prabhu, D.; Govindaraju, K.; Thiagarajan, R.; Arulvasu, C.; Dhanasekaran, G.; Dinesh, D.; Babu, G.

2014-06-01

A compound was isolated from Cassia auriculata leaves and characterized by high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), UV-vis spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). The in vitro anticancer effect of the compound isolated from C. auriculata was evaluated in human colon cancer cells HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cytotoxicity, nuclear morphology analysis and measurement of lactate dehydrogenase. The isolated compound 4-(2,5 dichlorobenzyl)-2,3,4,5,6,7 hexahydro7(4 methoxyphenyl)benzo[h][1,4,7] triazecin8(1H)-one showed 50% inhibition of HCT 15 cells when tested at 20 μg/ml after 24 h incubation. Cytotoxicity, nuclear morphology and lactate dehydrogenase assays clearly show potent anticancer activity of the isolated compound against colon cancer. Thus, the in vitro findings suggest that the compound isolated from C. auriculata leaves have potent anti-cancer properties with possible clinical applications.

Synthesis and characterization of d10 metal complexes of 3-Me-5-FcPz: Structural, theoretical and third order nonlinear optical properties

NASA Astrophysics Data System (ADS)

Senthilkumar, Kabali; Thirumoorthy, Krishnan; Vinitha, G.; Soni, Kiran; Bhuvanesh, Nattamai S. P.; Palanisami, Nallasamy

2017-01-01

The d10 metal complexes based on 3-methyl-5-ferrocenyl-1H-pyrazole (L = 3-Me-5-FcPz) ligand [M(L)4(NO3)2] Zn=(1) and Cd=(2), [Hg(L)4(NO3)2].dmf (3) have been synthesized and characterized by FT-IR, NMR, UV-Vis and elemental analysis. The molecular structure of compound 2 and its crystal packing were determined by single crystal X-ray diffraction. The nitrate anions are also involved in intermolecular hydrogen bonding with adjacent ferrocene units and it forms zig-zag one-dimensional polymeric structure. UV-Vis investigations on the positive solvatochromic behavior of 1-3 revealed that the solvation of the push-pull character increases with increasing polarity. The third-order nonlinear optical (NLO) properties of 1-3 have been determined by Z-scan technique and the results indicate that compounds 1-3 exhibits the strong self-defocusing effect. The nonlinear susceptibility χ(3) values are calculated in the order of 10-6 esu.

Unprecedented chemosensing behavior of novel tetra-substituted benzimidazole zinc(II) phthalocynine for selective detection of Bi3 + ion: Synthesis, characterization and ROS generation

NASA Astrophysics Data System (ADS)

Ullah, Azeem; Shah, Faheem; Khan, Imran; Anwar, Muhammad; Shah, Kiramat; Muhammad, Munira Taj; Ahmad, Farid

2018-03-01

In this work, synthesis of novel symmetrical 4-(2-bromo-4-(5-bromo-1H-benzo[d] imidazol-2-yl) phenoxy) tetra substituted zinc phthalocyanine has been reported. The novel benzimidazole zinc phthlocynine compound (3) has been characterized by MALDI-TOF MS, FT-IR, UV-vis, and 1H NMR spectroscopy. This new compound 3 displayed excellent selectivity towards Bi3 + ion in the presence of other competitive ions including Ca2 +, Cd2 +, Co2 + Cu2 +, Fe3 +, Hg2 +, Sn2 +, Mg2 +, Na+, Ni2 + and Pb2 + respectively. Upon addition of Bi3 + into the solution of compound 3 in DMSO, dramatic change was observed in the Q- and the B-bands in UV-visible spectra as a result of donor acceptor interactions. Reactive oxygen species (ROS) were also studied using 2,7-dichlorofluorescin diacetate (DCFH-DA) a fluorescent probe which is converted to highly fluorescent dichlorofluorescein (DCF) in the presence of ROS. This property of non-aggregating zinc phthalocyanine is promising as a photosensitizer in photodynamic therapy of cancer.

Synthesis and Spectral Characterization of Antifungal Sensitive Schiff Base Transition Metal Complexes

PubMed Central

Sakthivel, A.; Rajasekaran, K.

2007-01-01

New N2O2 donor type Schiff base has been designed and synthesized by condensing acetoacetanilido-4-aminoantipyrine with 2-aminobenzoic acid in ethanol. Solid metal complexes of the Schiff base with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) metal ions were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conduction, fast atom bombardment (FAB) mass, IR, UV-Vis, and 1H NMR spectral studies. The data show that the complexes have the composition of ML type. The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Candida albicans, Rhizoctonia bataicola and Trichoderma harizanum. All the metal complexes showed stronger antifungal activities than the free ligand. The minimum inhibitory concentrations (MIC) of the metal complexes were found in the range of 10~31 µg/ml. PMID:24015086

Photoabsorption and photodissociation of molecules important in the interstellar medium

NASA Technical Reports Server (NTRS)

Lee, Long C.; Suto, Masako

1991-01-01

The photoabsorption, photodissociation, and fluorescence cross sections of interstellar molecules are measured at 90 to 250 nm. These quantitative optical data are needed for the understanding of the formation and destruction processes of molecules under the intense interstellar UV radiation field. Research covering the following topics is presented: (1) fluorescences from photoexcitation of CH4, CH3OH, and CH3SH; (2) NO gamma emission from photoexcitation of NO; (3) photoexcitation cross sections of aromatic molecules; (4) IR emission from UV excitation of HONO2; (5) IR emission from UV excitation of benzene and methyl-derivitives; and (6) IR emission from UV excitation of polycyclic aromatic hydrocarbon molecules.

Chiral aldehydes in hydrocarbons: diastereoselective nucleophilic addition, NMR, and CD spectroscopy reveal dynamic solvation effects.

PubMed

Cainelli, Gianfranco; Galletti, Paola; Pieraccini, Silvia; Quintavalla, Arianna; Giacomini, Daria; Piero Spada, Gian

2004-01-01

Temperature-dependent studies on the diastereoselective nucleophilic addition of n- BuLi to alpha-chiral aldehydes as (S)-O-(t-butyl-dimethylsilyl)lactal, (S)-O-(t-butyl-dimethylsilyl) mandelic aldehyde, and (R)-2-phenylpropanal in n-decane and n-dodecane reveal dynamic solvation phenomena with the presence of inversion temperatures (T(inv)) in the Eyring plots of ln (anti/syn) vs. 1/ T. These dynamic solvent effects were disclosed by temperature-dependent studies of the (13)C NMR, CD, and UV spectra of the starting aldehydes in solution of n-decane and n-dodecane. The concomitant presence of three peculiar temperatures T(CD), T(UV), and T(NMR), whose values are identical and match T(inv), clearly confirms our earlier interpretation of the solvent-dependent nature of T(inv). The inversion temperature, as well as T(CD), T(UV), and T(NMR) represents the interconversion temperature of two different solvation clusters which act as two different supramolecules with different stereoselectivities. Copyright 2003 Wiley-Liss, Inc.

Preparation and characterization of conjugated polymers made by postpolymerization reactions of alternating polyketones.

PubMed

Cheng, Chen; Guironnet, Damien; Barborak, James; Brookhart, Maurice

2011-06-29

Conjugated polymers possessing a poly(2,5-dimethylene-2,5-dihydrofuran) backbone were prepared through postpolymerization reaction of styrenic polyketones with bromine in one-pot reactions. The modification is proposed to proceed via condensation of two repeating units to form a fully characterized polymer with a poly(2,5-dimethylenetetrahydrofuran) backbone. Subsequent bromination and elimination of HBr yield a polymer with a fully conjugated carbon backbone. The new conjugated polymers were characterized by NMR, IR, and UV-vis spectroscopies and by CV. These polymers have strong absorption in the visible region, with the absorption peaks shifted to the NIR region upon doping with acids. The ease of the synthesis of the starting polyketone and of the modifications allows large-scale preparation of those conjugated polymers.

Novel axially carborane-cage substituted silicon phthalocyanine photosensitizer; synthesis, characterization and photophysicochemical properties

NASA Astrophysics Data System (ADS)

Atmaca, Göknur Yaşa; Dizman, Cemil; Eren, Tarık; Erdoğmuş, Ali

2015-02-01

The novel axially dicarborane substituted silicon (IV) (SiPc-DC) phthalocyanine was synthesized by treating silicon phthalocyanine dichloride SiPc(Cl)2 (SiPc) with o-Carborane monool. The compound was characterized by mass spectrometry, UV-Vis, FT-IR, 1H and 11B Nuclear Magnetic Resonance Spectroscopy (NMR). Spectral, photophysical (fluorescence quantum yield) and photochemical (singlet oxygen (ΦΔ) and photodegradation quantum yield (Φd)) properties of the complex were reported in different solutions (Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF) and Toluene). The results of spectral measurements showed that both SiPc and carborane cage can have potential to be used as sensitizers in photodynamic therapy (PDT) and boron neutron capture therapy (BNCT) by their singlet oxygen efficiencies (ΦΔ = 0.41, 0.39).

Effects of counterions of colorful sandwich-type zinc(II) 4‧-phenyl-terpyridine compounds on photoluminescent and thermal properties

NASA Astrophysics Data System (ADS)

Zhang, Yongqiang; Zhou, Peng; Liang, Baohuan; Huang, Ling; Zhou, Yanling; Ma, Zhen

2017-10-01

Reactions between 4‧-phenyl-terpyridine (L) and several Zn(II) salts (p-toluenesulfonate, nitrate, trifluoromethane sulfonate or hexafluoroantimonate) led to the formation of the complexes [ZnL2](p-OSO2PhCH3)2 (1), [ZnL2](NO3)2 (2), [ZnL2](SO3CF3)2 (3) and [ZnL2](SbF6)2 (4), which were characterized by IR, 1H NMR, elemental analysis, UV-vis spectroscopies and single crystal X-ray diffraction, along with their TG-DTA thermal and photoluminescent properties. The four compounds show mononuclear Zn(II) structures with hexacoordinated, irregular ZnN6 octahedron geometries. Their colours and photo-luminescent properties have changed regularly depending on the counterions of the compounds.

Experimental and theoretical calculation studies on the structure elucidation and absolute configuration of calyxins from Alpinia katsumadai.

PubMed

Wang, Xiao-Bing; Yang, Chang-Shui; Luo, Jian-Guang; Zhang, Chao; Luo, Jun; Yang, Ming-Hua; Kong, Ling-Yi

2017-06-01

Six novel calyxins, named calyxin T-W, ent-calyxin T and ent-calyxin U were isolated from the seeds of Alpinia katsumadai Hayata. Their relative configurations were elucidated by means of detailed UV, IR, NMR and MS spectroscopic data. Their absolute configurations were assigned by collaborative studies on single crystal X-ray diffraction analysis, Mosher's method, electronic circular dichroism (ECD), optical rotation and theoretical calculations. These compounds are Friedel-Cranft alkylation adducts composed of coexisted diarylheptanoids and flavanone from the seeds of Alpinia katsumadai. The antiproliferative activity of the six compounds against NCI-H460, HeLa, SMMC-7721 and HCT-116 cell lines was also reported, and most of them showed moderate to strong activities. Copyright © 2017. Published by Elsevier B.V.

Ginkgolides and bilobalide: their physical, chromatographic and spectroscopic properties.

PubMed

van Beek, Teris A

2005-09-01

Ginkgolides A, B, C, J, K, L and M and bilobalide are rare terpene trilactones that have been isolated from leaves and root bark of the Chinese tree Ginkgo biloba. The structures of the highly oxidized ginkgolides were independently elucidated in the 1960s by the groups of Nakanishi and Sakabe. Later these compounds were found to be potent and selective antagonists of platelet activating factor, which fact triggered much new research. During the past 40 years, much physical, chromatographic and spectroscopic data have been published on these compounds in various, sometimes inaccessible, sources. The published melting points, solubility in different solvents, ionization constants, chromatographic behaviour, specific optical rotations, UV, IR, MS and NMR data, and X-ray studies are summarized and, where necessary, discussed. The literature until April 2005 has been reviewed.

New porphyrin-polyoxometalate hybrid materials: synthesis, characterization and investigation of catalytic activity in acetylation reactions.

PubMed

Araghi, Mehdi; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammdpoor-Baltork, Iraj

2012-10-14

New hybrid complexes based on covalent interaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatozinc(II) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatotin(IV) chloride, and a Lindqvist-type polyoxometalate, Mo(6)O(19)(2-), were prepared. These new porphyrin-polyoxometalate hybrid materials were characterized by (1)H NMR, FT IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided several spectral data for synthesis of these compounds. Cyclic voltammetry showed the influence of the polyoxometalate on the redox process of the porphyrin ring. The catalytic activity of tin(IV)porphyrin-hexamolybdate hybrid material was investigated in the acetylation of alcohols and phenols with acetic anhydride. The reusability of this catalyst was also investigated.

Three new benzolactones from Lavandula angustifolia and their bioactivities.

PubMed

Shi, Jian-Lian; Tang, Shi-Yun; Liu, Chun-Bo; Ye, Ling; Yang, Pei-Song; Zhang, Feng-Mei; He, Pei; Liu, Zhi-Hua; Miao, Ming-Ming; Guo, Ya-Dong; Shen, Qin-Peng

2017-08-01

Three new benzolactones (1-3), together with four known ones (4-7), were isolated from the whole herb of Lavandula angustifolia. Their structures were established on the basis of detailed spectroscopic analysis (1D- and 2D-NMR, HRESIMS, UV, and IR) and comparison with data reported in the literature. New compounds were evaluated for their anti-tobacco mosaic virus (TMV) activities and cytotoxic activities. The results revealed that compounds 1-3 showed obvious anti-TMV activities with inhibition rates of 26.9, 30.2, and 28.4%, which were at the same grade as positive control. Compounds 1-3 also showed weak inhibitory activities against some tested human tumor cell lines with IC 50 values in the range of 32.1-7.6 μM.

Sesquiterpenoids and lignans from the roots of Valeriana officinalis L.

PubMed

Wang, Peng-Cheng; Ran, Xin-Hui; Chen, Rui; Luo, Huai-Rong; Ma, Qing-Yun; Liu, Yu-Qing; Hu, Jiang-Miao; Huang, Sheng-Zhuo; Jiang, He-Zhong; Chen, Zhong-Quan; Zhou, Jun; Zhao, You-Xing

2011-10-01

Two new guaiane-type sesquiterpenoids, valerol A (1) and kessyl 3-acetate (2), together with nine known compounds, valeracetate (3), anismol A (4), orientalol C (5), spatulenol (6), 4α,10α-epoxyaromadendrane (7), (+)-8-hydroxypinoresinol (8), pinorespiol (9), pinoresinol 4-O-β-D-glucopyranoside (10), and 8-hydroxypinoresinol 4'-O-β-D-glucopyranoside (11) were isolated from the roots of Valeriana officinalis. The structures and relative configurations of 1 and 2 were elucidated on the basis of spectroscopic methods (1D- and 2D-NMR, MS, UV, and IR). These compounds were evaluated for inhibitory activity on acetylcholinesterase (AChE) and enhancing activity on nerve growth factor (NGF)-mediated neurite outgrowth in PC12 cells. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Novel polymer anchored Cr(III) Schiff base complexes: Synthesis, characterization and antimicrobial properties

NASA Astrophysics Data System (ADS)

Selvi, Canan; Nartop, Dilek

2012-09-01

New polymer-bound Schiff bases and Cr(III) complexes have been synthesized by the reaction of 4-benzyloxybenzaldehyde, polymer-bound with 2-aminophenol, 2-amino-4-chlorophenol and 2-amino-4-methylphenol. The structure of polymeric-Schiff bases and their Cr(III) complexes have been characterized by elemental analyses, magnetic measurements, IR, UV-Vis, TG-DTA and 1H-NMR. All these compounds have also been investigated for antibacterial activity by the well-diffusion method against Staphylococcus aureus (RSKK-07035), Shigella dysenteria type 10 (RSKK 1036), Listeria monocytogenes 4b(ATCC 19115, Escherichia coli (ATCC 1230), Salmonella typhi H (NCTC 901.8394), Staphylococcus epidermis (ATCC 12228), Brucella abortus (RSKK-03026), Micrococcs luteus (ATCC 93419, Bacillus cereus sp., Pseudomonas putida sp. and for antifungal activity against Candida albicans (Y-1200-NIH).

Synthesis, spectroscopic characterization and structural investigations of new adduct compound of carbazole with picric acid: DNA binding and antimicrobial studies

NASA Astrophysics Data System (ADS)

Saravanabhavan, Munusamy; Sathya, Krishnan; Puranik, Vedavati G.; Sekar, Marimuthu

2014-01-01

Carbazole picrate (CP), a new organic compound has been synthesized, characterized by various analytical and spectroscopic technique such as FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. An orthorhombic geometry was proposed based on single crystal XRD study. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it was stable up to 170 °C. Further, the newly synthesized title compound was tested for its in vitro antibacterial and antifungal activity against various bacterial and fungal species. Also, the compound was tested for its binding activity with Calf thymus (CT) DNA and the results show a considerable interaction between CP and CT-DNA.

Anti-Lymphangiogenesis Components from Zoanthid Palythoa tuberculosa

PubMed Central

Chen, Shu-Rong; Wang, Shih-Wei; Su, Chien-Jung; Hu, Hao-Chun; Hsieh, Chi-Ting; Peng, Chia-Chi

2018-01-01

Three new compounds, tuberazines A–C (1–3), and eleven known compounds (4–14) were obtained from the ethanolic extract of Taiwanese zoanthid Palythoa tuberculosa. Compounds 1–4 are rare marine natural products with a pyrazine moiety, and compound 5 is a tricyclic tryptamine derivative isolated from nature for the first time. The structures of all isolated metabolites were determined by analyzing their IR, Mass, NMR, and UV spectrometric data. The absolute configuration of 1 was confirmed by comparing the trend of experimental electronic circular dichroism (ECD) with calculated ECD spectra. The anti-lymphangiogenic activities of new compounds were evaluated in human lymphatic endothelial cells (LECs). Of these, new compound 3 displayed the most potent anti-lymphangiogenesis property by suppressing cell growth and tube formation of LECs. PMID:29385063

Photodegradation of hexythiazox in different solvent systems under the influence of ultraviolet light and sunlight in the presence of TiO2, H2O2, and KNO3 and identification of the photometabolites.

PubMed

Mandal, Sudeb; Joardar, Soumen; Das, Saktipada; Bhattacharyya, Anjan

2011-11-09

The photodegradation of the carboxamide acaricide hexythiazox in three different solvent systems (aqueous methanolic, aqueous isopropanolic, and aqueous acetonitrilic solutions) in the presence of H(2)O(2), KNO(3), and TiO(2) under ultraviolet (UV) light (λ(max) ≥ 250 nm) and sunlight (λ(max) ≥290 nm) has been assessed in this work. The kinetics of photodecomposition of hexythiazox and the identification of photoproducts were carried out using liquid chromatography-mass spectrometry. The rate of photodecomposition of hexythiazox in different solvents followed first-order kinetics in both UV radiation and natural sunlight, and the degradation rates were faster under UV light than under sunlight. Hexythiazox was found to be more efficiently photodegraded in the presence of TiO(2) than in the presence of H(2)O(2) and KNO(3). Two major photoproducts were separated in pure form using column chromatography and identified according to IR, (1)H NMR, and mass spectral information as cyclohexylamine and 5-(4-chlorophenyl)-4-methylthiazolidin-2-one. Another nine photoproducts were identified according to LC-MS/MS spectral information. The plausible photodegradation pathways of hexythiazox were proposed according to the structures of the photoproducts.

Synthesis, characterization, cytotoxicity, cell cycle analysis of 3-(4-methoxyphenyl)-1-(pyridin-2-ylmethyl)thiourea and quantum chemical analyses

NASA Astrophysics Data System (ADS)

Mushtaque, Md.; Avecilla, Fernando; Khan, Md. Shahzad; Hafeez, Zubair Bin; Rezvi, M. Moshahid A.; Srivastava, Anurag

2017-08-01

Thiourea derivative,3-(4-methoxyphenyl)-1-(pyridin-2-ylmethyl)thiourea, was synthesized. The structure of the synthesized compound (3) was elucidated by IR, UV-visible, 1H NMR, mass Spectrometry, and X-ray single crystal structure. The computational quantum chemical studies like, IR, UV, NBO analysis were performed by DFT with Becke-3-Lee-Yang- Parr (B3LYP) exchange-correlation functional in combination with 6-311++G(d,p) basis sets. It was observed experimentally and theoretically that compound (3) exhibited syn-anti-conformation around sulphur atom. The DNA-binding constant Kb was found 3.3 × 106 Lmol-1. The docking energy of compound (3) with 1BNA was found -6.2 kcal/mol. MTT-assay against HepG2 (IC50 = 140.39) and Siha (IC50 = 119.87 μM) cell lines revealed that compound (3) wasnon-toxic up to140.39 μM against HepG2 and 119.87 μM against Siha cells respectively. It was also found that compound (3) is non-toxic against normal human cell line HEK-293(IC50 = 148.67 μM). Cell cycle analyses displayed that treated HepG2 cells at 40 μM and 80 μM showed 65% and 70% arrest in G0/G1with respect to untreated controls (60%) and Siha cells at the same concentration displayed 59% and 65% arrest with respect to G0/G1 as compared to untreated control (45%).

Investigating pyridazine and phthalazine exchange in a series of iridium complexes in order to define their role in the catalytic transfer of magnetisation from para-hydrogen.

PubMed

Appleby, Kate M; Mewis, Ryan E; Olaru, Alexandra M; Green, Gary G R; Fairlamb, Ian J S; Duckett, Simon B

2015-07-01

The reaction of [Ir(IMes)(COD)Cl], [IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, COD = 1,5-cyclooctadiene] with pyridazine (pdz) and phthalazine (phth) results in the formation of [Ir(COD)(IMes)(pdz)]Cl and [Ir(COD)(IMes)(phth)]Cl. These two complexes are shown by nuclear magnetic resonance (NMR) studies to undergo a haptotropic shift which interchanges pairs of protons within the bound ligands. When these complexes are exposed to hydrogen, they react to form [Ir(H) 2 (COD)(IMes)(pdz)]Cl and [Ir(H) 2 (COD)(IMes)(phth)]Cl, respectively, which ultimately convert to [Ir(H) 2 (IMes)(pdz) 3 ]Cl and [Ir(H) 2 (IMes)(phth) 3 ]Cl, as the COD is hydrogenated to form cyclooctane. These two dihydride complexes are shown, by NMR, to undergo both full N-heterocycle dissociation and a haptotropic shift, the rates of which are affected by both steric interactions and free ligand p K a values. The use of these complexes as catalysts in the transfer of polarisation from para -hydrogen to pyridazine and phthalazine via signal amplification by reversible exchange (SABRE) is explored. The possible future use of drugs which contain pyridazine and phthalazine motifs as in vivo or clinical magnetic resonance imaging probes is demonstrated; a range of NMR and phantom-based MRI measurements are reported.

Quantum-chemical, NMR, FT IR, and ESI MS studies of complexes of colchicine with Zn(II).

PubMed

Jankowski, Wojciech; Kurek, Joanna; Barczyński, Piotr; Hoffmann, Marcin

2017-04-01

Colchicine is a tropolone alkaloid from Colchicinum autumnale. It shows antifibrotic, antimitotic, and anti-inflammatory activities, and is used to treat gout and Mediterranean fever. In this work, complexes of colchicine with zinc(II) nitrate were synthesized and investigated using DFT, 1 H and 13 C NMR, FT IR, and ESI MS. The counterpoise-corrected and uncorrected interaction energies of these complexes were calculated. We also calculated their 1 H, 13 C NMR, and IR spectra and compared them with the corresponding experimentally obtained data. According to the ESI MS mass spectra, colchicine forms stable complexes with zinc(II) nitrate that have various stoichiometries: 2:1, 1:1:1, and 2:1:1 with respect to colchichine, Zn(II), and nitrate ion. All of the complexes were investigated using the quantum theory of atoms in molecules (QTAIM). The calculated and the measured spectra showed differences before and after the complexation process. Calculated electron densities and bond critical points indicated the presence of bonds between the ligands and the central cation in the investigated complexes that satisfied the quantum theory of atoms in molecules. Graphical Abstract DFT, NMR, FT IR, ESI MS, QTAIM and puckering studies of complexes of colchicine with Zn(II).

Reaction pathways of proton transfer in hydrogen-bonded phenol-carboxylate complexes explored by combined UV-vis and NMR spectroscopy.

PubMed

Koeppe, Benjamin; Tolstoy, Peter M; Limbach, Hans-Heinrich

2011-05-25

Combined low-temperature NMR/UV-vis spectroscopy (UVNMR), where optical and NMR spectra are measured in the NMR spectrometer under the same conditions, has been set up and applied to the study of H-bonded anions A··H··X(-) (AH = 1-(13)C-2-chloro-4-nitrophenol, X(-) = 15 carboxylic acid anions, 5 phenolates, Cl(-), Br(-), I(-), and BF(4)(-)). In this series, H is shifted from A to X, modeling the proton-transfer pathway. The (1)H and (13)C chemical shifts and the H/D isotope effects on the latter provide information about averaged H-bond geometries. At the same time, red shifts of the π-π* UV-vis absorption bands are observed which correlate with the averaged H-bond geometries. However, on the UV-vis time scale, different tautomeric states and solvent configurations are in slow exchange. The combined data sets indicate that the proton transfer starts with a H-bond compression and a displacement of the proton toward the H-bond center, involving single-well configurations A-H···X(-). In the strong H-bond regime, coexisting tautomers A··H···X(-) and A(-)···H··X are observed by UV. Their geometries and statistical weights change continuously when the basicity of X(-) is increased. Finally, again a series of single-well structures of the type A(-)···H-X is observed. Interestingly, the UV-vis absorption bands are broadened inhomogeneously because of a distribution of H-bond geometries arising from different solvent configurations.

Comparison of Attenuated Total Reflectance Mid-Infrared, Near Infrared, and 1H-Nuclear Magnetic Resonance Spectroscopies for the Determination of Coffee's Geographical Origin

PubMed Central

Caro Rodríguez, Diana; Arana, Victoria A.; Bernal, Andrés; Esseiva, Pierre

2017-01-01

The sensorial properties of Colombian coffee are renowned worldwide, which is reflected in its market value. This raises the threat of fraud by adulteration using coffee grains from other countries, thus creating a demand for robust and cost-effective methods for the determination of geographical origin of coffee samples. Spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), near infrared (NIR), and mid-infrared (mIR) have arisen as strong candidates for the task. Although a body of work exists that reports on their individual performances, a faithful comparison has not been established yet. We evaluated the performance of 1H-NMR, Attenuated Total Reflectance mIR (ATR-mIR), and NIR applied to fraud detection in Colombian coffee. For each technique, we built classification models for discrimination by species (C. arabica versus C. canephora (or robusta)) and by origin (Colombia versus other C. arabica) using a common set of coffee samples. All techniques successfully discriminated samples by species, as expected. Regarding origin determination, ATR-mIR and 1H-NMR showed comparable capacity to discriminate Colombian coffee samples, while NIR fell short by comparison. In conclusion, ATR-mIR, a less common technique in the field of coffee adulteration and fraud detection, emerges as a strong candidate, faster and with lower cost compared to 1H-NMR and more discriminating compared to NIR. PMID:29201055

Low cost, patterning of human hNT brain cells on parylene-C with UV & IR laser machining.

PubMed

Raos, Brad J; Unsworth, C P; Costa, J L; Rohde, C A; Doyle, C S; Delivopoulos, E; Murray, A F; Dickinson, M E; Simpson, M C; Graham, E S; Bunting, A S

2013-01-01

This paper describes the use of 800nm femtosecond infrared (IR) and 248nm nanosecond ultraviolet (UV) laser radiation in performing ablative micromachining of parylene-C on SiO2 substrates for the patterning of human hNT astrocytes. Results are presented that support the validity of using IR laser ablative micromachining for patterning human hNT astrocytes cells while UV laser radiation produces photo-oxidation of the parylene-C and destroys cell patterning. The findings demonstrate how IR laser ablative micromachining of parylene-C on SiO2 substrates can offer a low cost, accessible alternative for rapid prototyping, high yield cell patterning.

DirtyGrid I: 3D Dust Radiative Transfer Modeling of Spectral Energy Distributions of Dusty Stellar Populations

NASA Astrophysics Data System (ADS)

Law, Ka-Hei; Gordon, Karl D.; Misselt, Karl A.

2018-06-01

Understanding the properties of stellar populations and interstellar dust has important implications for galaxy evolution. In normal star-forming galaxies, stars and the interstellar medium dominate the radiation from ultraviolet (UV) to infrared (IR). In particular, interstellar dust absorbs and scatters UV and optical light, re-emitting the absorbed energy in the IR. This is a strongly nonlinear process that makes independent studies of the UV-optical and IR susceptible to large uncertainties and degeneracies. Over the years, UV to IR spectral energy distribution (SED) fitting utilizing varying approximations has revealed important results on the stellar and dust properties of galaxies. Yet the approximations limit the fidelity of the derived properties. There is sufficient computer power now available that it is now possible to remove these approximations and map out of landscape of galaxy SEDs using full dust radiative transfer. This improves upon previous work by directly connecting the UV, optical, and IR through dust grain physics. We present the DIRTYGrid, a grid of radiative transfer models of SEDs of dusty stellar populations in galactic environments designed to span the full range of physical parameters of galaxies. Using the stellar and gas radiation input from the stellar population synthesis model PEGASE, our radiative transfer model DIRTY self-consistently computes the UV to far-IR/sub-mm SEDs for each set of parameters in our grid. DIRTY computes the dust absorption, scattering, and emission from the local radiation field and a dust grain model, thereby physically connecting the UV-optical to the IR. We describe the computational method and explain the choices of parameters in DIRTYGrid. The computation took millions of CPU hours on supercomputers, and the SEDs produced are an invaluable tool for fitting multi-wavelength data sets. We provide the complete set of SEDs in an online table.

Experimental (FT-IR, FT-Raman, 1H, 13C NMR) and theoretical study of alkali metal 2-aminobenzoates

NASA Astrophysics Data System (ADS)

Samsonowicz, M.; Świsłocka, R.; Regulska, E.; Lewandowski, W.

2008-09-01

The influence of lithium, sodium, potassium, rubidium and cesium on the electronic system of the 2-aminobenzoic acid was studied by the methods of molecular spectroscopy. The vibrational (FT-IR, FT-Raman) and NMR ( 1H and 13C) spectra for 2-aminobenzoic acid and its alkali metal salts were recorded. The assignment of vibrational spectra was done on the basis of literature data, theoretical calculations and our previous experience. Characteristic shifts of bands and changes in intensities of bands along the metal series were observed. The changes of chemical shifts of protons ( 1H NMR) and carbons ( 13C NMR) in the series of studied alkali metal 2-aminobenzoates were observed too. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G ∗∗ basis set. Geometric aromaticity indices, dipole moments and energies were also calculated. The theoretical wavenumbers and intensities of IR and Raman spectra were obtained. The calculated parameters were compared to experimental characteristic of studied compounds.

Experimental and theoretical (FT-IR, FT-Raman, UV-vis, NMR) spectroscopic analysis and first order hyperpolarizability studies of non-linear optical material: (2E)-3-[4-(methylsulfanyl) phenyl]-1-(4-nitrophenyl) prop-2-en-1-one using density functional theory.

PubMed

Kumar, Amit; Deval, Vipin; Tandon, Poonam; Gupta, Archana; Deepak D'silva, E

2014-09-15

A combined experimental and theoretical investigation on FT-IR, FT-Raman, NMR, UV-vis spectra of a chalcone derivative (2E)-3-[4-(methylsulfanyl) phenyl]-1-(4-nitrophenyl) prop-2-en-1-one (4N4MSP) has been reported. 4N4MSP has two planar rings connected through conjugated double bond and it provides a necessary configuration to show non-linear optical (NLO) response. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) with B3LYP functional and 6-311++G(d,p) basis set combination. The analysis of the fundamental modes was made with the help of potential energy distribution (PED). Molecular electrostatic potential (MEP) surface was plotted over the geometry primarily for predicting sites and relative reactivities towards electrophilic and nucleophilic attack. The delocalization of electron density of various constituents of the molecule has been discussed with the aid of NBO analysis. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were calculated by time-dependent density functional theory (TD-DFT) and the results complement the experimental findings. The recorded and calculated 1H chemical shifts in gas phase and MeOD solution are gathered for reliable calculations of magnetic properties. Thermodynamic properties like heat capacity (C°p,m), entropy (S°m), enthalpy (H°m) have been calculated for the molecule at the different temperatures. Based on the finite-field approach, the non-linear optical (NLO) parameters such as dipole moment, mean polarizability, anisotropy of polarizability and first order hyperpolarizability of 4N4MSP molecule are calculated. The predicted first hyperpolarizability shows that the molecule has a reasonably good nonlinear optical (NLO) behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

Structural properties of dissolved organic carbon in deep horizons of an arable soil.

NASA Astrophysics Data System (ADS)

Lavaud, A.; Croué, Jp; Berwick, L.; Steffens, M.; Chabbi, A.

2010-05-01

The objective of this work is to quantity the DOC that percolates in deep horizons of an arable soil, and to characterize the structural properties of the main fractions. The study was conducted on the long term observatory for environmental research- biogeochemical cycles and biodiversity Lusignan site-France. DOC collected using lysimeter plates inserted to a depth of 105 cm was fractionated into 3 fractions using the two column array of XAD-8 and XAD-4 resins. The HPO (hydrophobic) fraction (i.e. humic substances) isolated from the XAD-8 resin, the TPH (Transphilic) fraction from the XAD-4 resin and the HPI (hydrophilic) fraction which corresponds to the DOC that does not adsorbed onto the two resins under the acid condition used (pH 2). DOM adsorbed onto the resins is recovered with a 75%/25% acetonitrile/water mixture and lyophilized. The hydrophilic fraction is purified according the protocol proposed by Aiken and Leenheer (1993). The isolated fractions were subjected to several characterization tools: UV/Vis, fluorescence EEM, HPSEC/UV/DOC, 13C NMR, 14C dating, FT-IR, pyrolysis, thermochemolysis and MSSV GC/MS. The DOC content ranged from 1 to 2.5 mg / L between winter and the middle of spring and then to 4-5 mg / L in summer time. For all isolated fractions HPSEC analyses indicated the predominance of low molecular structures with a low aromatic character. Fluorescence EEM confirmed the non-humic character of the DOM. 13C-NMR spectra showed that the aromatic character decreased from HPO to TPH, and HPI character. Molecular size follows the same trend. HPI DOM was found to be strongly enriched in carboxyl groups. The 14C concentration of the HPO fraction corresponds to an apparent calibrated age around AD 1500. For the same fraction isolated from the 0 - 30 cm horizon, the measured 14C concentration 131.9 pMC corresponds to that in the atmosphere around AD 1978. Significant input of terpenoid derived organic matter was confirmed in the HPO fraction of DOC, results supported by the data of 13C NMR, FT-IR and Micro Scale Sealed Vessel / pyrolysis GC / MS. Flash pyrolysis GC / MS chromatogram highlight the presence of phenol and alkyl phenols, generally attributed to structures polyhydroxyaromatic structures. Acetamide, a pyrolysis product of amino sugars constituents of microbial cell wall is also significantly present. The thermochimiolysis (TMAH)/GC/ MS confirmed the presence of hydroxy aromatic structures in the extracts; however, their precise origin (lignin, tannins ...) remains uncertain.

Optical radiation in modern medicine

PubMed Central

Sowa, Paweł; Rutkowska-Talipska, Joanna; Rutkowski, Krzysztof; Kosztyła-Hojna, Bożena

2013-01-01

Optical radiation extends between microwaves and X-rays of the electromagnetic radiation and includes ultraviolet (UV), visible light (VL) and infrared (IR) components. The dose of radiation that reaches the skin is influenced by the ozone layer, position of the Sun, latitude, altitude, cloud cover and ground reflections. The photobiological effects of UV, VL and IR bands depend on their wavelength, frequency and mechanism of action. They are modified by the thickness, structure, vasculature and pigmentation of skin's stratum corneum, epidermis and dermis. Following absorption, IR affects the body mainly through transfer of thermal energy to tissues. Visible light and skin interact either thermally or photochemically, whereas UV acts mainly photochemically. Optical radiation in the form of sunlight therapy had been used already in ancient times. Nowadays IR, VL and UV are widely applied in the therapy of allergic, dermatological, cardiovascular, respiratory, rheumatic, neonatal, pediatric and psychiatric disorders. PMID:24278082

Uridine Nucleoside Thiation: Gas-Phase Structures and Energetics

NASA Astrophysics Data System (ADS)

Hamlow, Lucas; Lee, Justin; Rodgers, M. T.; Berden, Giel; Oomens, Jos

2016-06-01

The naturally occurring thiated uridine nucleosides, 4-thiouridine (s4Urd) and 2-thiouridine (s2Urd), play important roles in the function and analysis of a variety of RNAs. 2-Thiouridine and its C5 modified analogues are commonly found in tRNAs and are believed to play an important role in codon recognition possibly due to their different structure, which has been shown by NMR to be predominantly C3'-endo. 2-Thiouridine may also play an important role in facilitating nonenzymatic RNA replication and transcription. 4-Thiouridine is a commonly used photoactivatable crosslinker that is often used to study RNA-RNA and RNA-protein cross-linking behavior. Differences in the base pairing between uracil and 4-thiouracil with adenine and guanine are an important factor in their role as a cross linker. The photoactivity of s4Urd may also aid in preventing near-UV lethality in cells. An understanding of their intrinsic structure in the gas-phase may help further elucidate the roles these modified nucleosides play in the regulation of RNAs. In this work, infrared multiple photon dissociation (IRMPD) action spectra of the protonated forms of s2Urd and s4Urd were collected in the IR fingerprint region. Structural information is determined by comparison with theoretical linear IR spectra generated from density functional theory calculations using molecular modeling to generate low-energy candidate structures. Present results are compared with analogous results for the protonated forms of uridine and 2'-deoxyuridine as well as solution phase NMR data and crystal structures.

Charge transfer complex between 2,3-diaminopyridine with chloranilic acid. Synthesis, characterization and DFT, TD-DFT computational studies

NASA Astrophysics Data System (ADS)

Al-Ahmary, Khairia M.; Habeeb, Moustafa M.; Al-Obidan, Areej H.

2018-05-01

New charge transfer complex (CTC) between the electron donor 2,3-diaminopyridine (DAP) with the electron acceptor chloranilic (CLA) acid has been synthesized and characterized experimentally and theoretically using a variety of physicochemical techniques. The experimental work included the use of elemental analysis, UV-vis, IR and 1H NMR studies to characterize the complex. Electronic spectra have been carried out in different hydrogen bonded solvents, methanol (MeOH), acetonitrile (AN) and 1:1 mixture from AN-MeOH. The molecular composition of the complex was identified to be 1:1 from Jobs and molar ratio methods. The stability constant was determined using minimum-maximum absorbances method where it recorded high values confirming the high stability of the formed complex. The solid complex was prepared and characterized by elemental analysis that confirmed its formation in 1:1 stoichiometric ratio. Both IR and NMR studies asserted the existence of proton and charge transfers in the formed complex. For supporting the experimental results, DFT computations were carried out using B3LYP/6-31G(d,p) method to compute the optimized structures of the reactants and complex, their geometrical parameters, reactivity parameters, molecular electrostatic potential map and frontier molecular orbitals. The analysis of DFT results strongly confirmed the high stability of the formed complex based on existing charge transfer beside proton transfer hydrogen bonding concordant with experimental results. The origin of electronic spectra was analyzed using TD-DFT method where the observed λmax are strongly consisted with the computed ones. TD-DFT showed the contributed states for various electronic transitions.

A structural study of fentanyl by DFT calculations, NMR and IR spectroscopy

NASA Astrophysics Data System (ADS)

Asadi, Zahra; Esrafili, Mehdi D.; Vessally, Esmail; Asnaashariisfahani, Manzarbanou; Yahyaei, Saeideh; Khani, Ali

2017-01-01

N-(1-(2-phenethyl)-4-piperidinyl-N-phenyl-propanamide (fentanyl) is synthesized and characterized by FT-IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analyses. The geometry optimization is performed using the B3LYP and M06 density functionals with 6-311 + G(d) and 6-311++G(d,p) basis sets. The complete assignments are performed on the basis of the potential energy distribution (PED) of the all vibrational modes. Almost a nice correlation is found between the calculated 13C chemical shifts and experimental data. The frontier molecular orbitals and molecular electrostatic potential of fentanyl are also obtained.

Synthesis of mesoporous zeolite single crystals with cheap porogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao Haixiang; Li Changlin; Ren Jiawen

2011-07-15

Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals have been successfully synthesized by adding soluble starch or sodium carboxymethyl cellulose (CMC) to a conventional zeolite synthesis system. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption analysis, {sup 27}Al magic angle spinning nuclear magnetic resonance ({sup 27}Al MAS NMR), temperature-programmed desorption of ammonia (NH{sub 3}-TPD) and ultraviolet-visible spectroscopy (UV-vis). The SEM images clearly show that all zeolite crystals possess the similar morphology with particle size of about 300 nm, the TEM images reveal that irregular intracrystalmore » pores are randomly distributed in the whole crystal. {sup 27}Al MAS NMR spectra indicate that nearly all of the Al atoms are in tetrahedral co-ordination in ZSM-5, UV-vis spectra confirm that nearly all of titanium atoms are incorporated into the framework of TS-1. The catalytic activity of meso-ZSM-5 in acetalization of cyclohexanone and meso-TS-1 in hydroxylation of phenol was also studied. The synthesis method reported in this paper is cost-effective and environmental friendly, can be easily expended to prepare other hierarchical structured zeolites. - Graphical abstract: Mesoporous zeolite single crystals were synthesized by using cheap porogens as template. Highlights: > Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals were synthesized. > Soluble starch or sodium carboxymethyl cellulose (CMC) was used as porogens. > The mesoporous zeolites had connected mesopores although closed pores existed. > Higher catalytic activities were obtained.« less

Interaction of lafutidine in binding to human serum albumin in gastric ulcer therapy: STD-NMR, WaterLOGSY-NMR, NMR relaxation times, Tr-NOESY, molecule docking, and spectroscopic studies.

PubMed

Yang, Hongqin; Huang, Yanmei; He, Jiawei; Li, Shanshan; Tang, Bin; Li, Hui

2016-09-15

In this study, lafutidine (LAF) was used as a model compound to investigate the binding mechanism between antiulcer drugs and human serum albumin (HSA) through various techniques, including STD-NMR, WaterLOGSY-NMR, (1)H NMR relaxation times, tr-NOESY, molecule docking calculation, FT-IR spectroscopy, and CD spectroscopy. The analyses of STD-NMR, which derived relative STD (%) intensities, and WaterLOGSY-NMR, determined that LAF bound to HSA. In particular, the pyridyl group of LAF was in close contact with HSA binding pocket, whereas furyl group had a secondary binding. Competitive STD-NMR and WaterLOGSY-NMR experiments, with warifarin and ibuprofen as site-selective probes, indicated that LAF preferentially bound to site II in the hydrophobic subdomains IIIA of HSA. The bound conformation of LAF at the HSA binding site was further elucidated by transferred NOE effect (tr-NOESY) experiment. Relaxation experiments provided quantitative information about the relationship between the affinity and structure of LAF. The molecule docking simulations conducted with AutoDock and the restraints derived from STD results led to three-dimensional models that were consistent with the NMR spectroscopic data. The presence of hydrophobic forces and hydrogen interactions was also determined. Additionally, FT-IR and CD spectroscopies showed that LAF induced secondary structure changes of HSA. Copyright © 2016 Elsevier Inc. All rights reserved.

Structure analysis and spectroscopic characterization of 2-Fluoro-3-Methylpyridine-5-Boronic Acid with experimental (FT-IR, Raman, NMR and XRD) techniques and quantum chemical calculations

NASA Astrophysics Data System (ADS)

Alver, Özgür; Dikmen, Gökhan

2016-03-01

Possible stable conformers, geometrical molecular structures, vibrational properties as well as band assignments, nuclear magnetic shielding tensors of 2-Fluoro-3-Methylpyridine-5-Boronic Acid (2F3MP5BA) were studied experimentally and theoretically using FT-IR, Raman, (CP/MAS) NMR and XRD spectroscopic methods. FT-IR and Raman spectra were evaluated in the region of 3500-400 cm-1, and 3200-400 cm-1, respectively. The optimized geometric structures, vibrational wavenumbers and nuclear magnetic shielding tensors were examined using Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. 1H, 13C NMR chemical shifts were calculated using the gauge invariant atomic orbital (GIAO) method. 1H, 13C, APT and HETCOR NMR experiments of title molecule were carried out in DMSO solution. 13C CP/MAS NMR measurement was done with 4 mm zirconium rotor and glycine was used as an external standard. Single crystal of 2F3MP5BA was also prepared for XRD measurements. Assignments of vibrational wavenumbers were also strengthened by calculating the total energy distribution (TED) values using scaled quantum mechanical (SQM) method.

Forensic Drug Identification, Confirmation, and Quantification Using Fully Integrated Gas Chromatography with Fourier Transform Infrared and Mass Spectrometric Detection (GC-FT-IR-MS).

PubMed

Lanzarotta, Adam; Lorenz, Lisa; Voelker, Sarah; Falconer, Travis M; Batson, JaCinta S

2018-05-01

This manuscript is a continuation of a recent study that described the use of fully integrated gas chromatography with direct deposition Fourier transform infrared detection and mass spectrometric detection (GC-FT-IR-MS) to identify and confirm the presence of sibutramine and AB-FUBINACA. The purpose of the current study was to employ the GC-FT-IR portion of the same instrument to quantify these compounds, thereby demonstrating the ability to identify, confirm, and quantify drug substances using a single GC-FT-IR-MS unit. The performance of the instrument was evaluated by comparing quantitative analytical figures of merit to those measured using an established, widely employed method for quantifying drug substances, high performance liquid chromatography with ultraviolet detection (HPLC-UV). The results demonstrated that GC-FT-IR was outperformed by HPLC-UV with regard to sensitivity, precision, and linear dynamic range (LDR). However, sibutramine and AB-FUBINACA concentrations measured using GC-FT-IR were not significantly different at the 95% confidence interval compared to those measured using HPLC-UV, which demonstrates promise for using GC-FT-IR as a semi-quantitative tool at the very least. The most significant advantage of GC-FT-IR compared to HPLC-UV is selectivity; a higher level of confidence regarding the identity of the analyte being quantified is achieved using GC-FT-IR. Additional advantages of using a single GC-FT-IR-MS instrument for identification, confirmation, and quantification are efficiency, increased sample throughput, decreased consumption of laboratory resources (solvents, chemicals, consumables, etc.), and thus cost.

Experimental and computational approaches to the analysis of the molecular structure of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile

NASA Astrophysics Data System (ADS)

Al-Azmi, Amal; Shalaby, Mona Abbas

2018-03-01

A green, fast and straightforward procedure for the synthesis of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile is described in this paper. The method uses a coupling reaction between 4- nitrophenyl diazonium chloride and 5-aminopyrazole-4-carbonitrile. The structure is confirmed by different spectroscopic studies such as IR, NMR, HRMS and UV-vis spectroscopy in addition to X-ray single-crystal determination. The molecular geometry, vibrational frequencies and gauge-invariant atomic orbital (GIAO) 1H and 13C NMR chemical shift values of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile are calculated in the ground state using the Hartree-Fock (HF) method and density functional theory (DFT) with the 6-31G(d) basis set, and are compared with the experimental data. The natural bond orbital (NBO) analysis is performed so as to discuss the stability of the molecule that arises from hyper conjugative interactions and charge delocalization. The electronic properties, such as HOMO and LUMO energies, were calculated using time dependent density functional theory (TD-DFT) approach.

Comparative study of lignin characteristics from wheat straw obtained by soda-AQ and kraft pretreatment and effect on the following enzymatic hydrolysis process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Haitao; Xie, Yimin; Zheng, Xing

With this study, to understand the structural changes of lignin after soda-AQ and kraft pretreatment, milled straw lignin, black liquor lignin and residual lignin extracted from wheat straw were characterized by FT-IR, UV, GPC and NMR. The results showed that the main lignin linkages were β-aryl ether substructures (β-O-4'), followed by phenylcoumaran (β-5') and resinol (β-β') substructures, while minor content of spirodienone (β-1'), dibenzodioxocin (5-5') and α,β-diaryl ether linkages were detected as well. After pretreatment, most lignin inter-units and lignin-carbohydrate complex (LCC) linkages were degraded and dissolved in black liquor, with minor amount left in residual pretreated biomass. In addition,more » through quantitative 13C and 2D-HSQC NMR spectral analysis, lignin and LCC were found to be more degraded after kraft pretreatment than soda-AQ pretreatment. Furthermore, the subsequent enzymatic hydrolysis results showed that more cellulose in wheat straw was converted to glucose after kraft pretreatment, indicating that LCC linkages were important in the enzymatic hydrolysis process.« less

Separation and Purification of Ombuoside from Gynostemma Pentaphyllum by Microwave-Assisted Extraction Coupled with High-Speed Counter-current Chromatography.

PubMed

Jiang, Wenhui; Shan, Hu; Song, Jiying; Lü, Haitao

2017-01-01

A rapid and efficient method for the separation and purification of ombuoside from Gynostemma pentaphyllum by microwave-assisted extraction coupled with high-speed counter-current chromatography (HSCCC) was successfully developed. Using an orthogonal array design L 9 (3 4 ), the extraction conditions, including microwave power, irradiation time, solid-to-liquid ratio and extraction times, were optimized. Ombuoside was isolated and purified from the crude extraction by HSCCC with two-phase solvent system composed of n-hexane:ethyl acetate:ethanol:water (5:6:5:5, v/v) in a single run. A 210 mg quantity of the crude extract containing 2.16% ombuoside was loaded, yielding 3.9 mg of ombuoside at 96.7% purity. The chemical structure of ombuoside was determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as UV, FT-IR, ESI-MS, 1 H NMR and 13 C NMR spectra. The purified ombuoside had strong 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radical scavenging activities. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Synthesis, characterization, spectroscopic and antioxidation studies of Cu(II)-morin complex

NASA Astrophysics Data System (ADS)

Panhwar, Qadeer Khan; Memon, Shahabuddin; Bhanger, M. I.

2010-04-01

Complex formation between copper (II) sulfate and morin (3,5,7,2',4'-pentahydroxyflavone) have been studied in methanol. Structure of the complex was determined through various analytical techniques including UV-vis, IR, 1H NMR, thermal, gravimetric and elemental analyses. The stoichiometric ratio for the reaction between the flavonoid and the metal ion in methanol has been determined by Job's method and elemental analysis for metal content of complex by titration with EDTA, which confirm that morin forms a 1:1 metal:ligand complex. 1H NMR study reveals that, 3OH and 4CO groups of morin take part in complexation with a copper ion. Individual stress was given to the site of central ion and composition of the complex. Antioxidant activity of the complex was evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, which showed that the antioxidant activity of complexed morin has higher value as compared to the free morin. Moreover, it was observed that the metal complex is sufficiently stable as well as the data indicates the spontaneous formation of complex (-Δ G) that is exothermic in nature (-Δ H) and entropically unfavourable (-Δ S).

One-Pot Synthesis, Spectroscopic and Physicochemical Studies of Quinoline Based Blue Emitting Donor-Acceptor Chromophores with Their Biological Application.

PubMed

Asiri, Abdullah M; Khan, Salman A; Al-Thaqafya, Saad H

2015-09-01

Blue emitting cyano substituted isoquinoline dyes were synthesized by one-pot multicomponent reactions (MCRs) of aldehydes, malononitrile, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Results obtained from spectroscopic (FT-IR, (1)H-NMR, (13)C-NMR, EI-MS) and elemental analysis of synthesized compounds was in good agreement with their chemical structures. UV-vis and fluorescence spectroscopy measurements proved that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of synthesized compounds. The anti-bacterial activity of these compounds were first studied in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria then the minimum inhibitory concentration (MIC) was determined with the reference of standard drug chloramphenicol. The results displayed that compound 3 was better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) than chloramphenicol. Graphical Abstract ᅟ.

Synthesis, structure-activity relationship and molecular docking of cyclohexenone based analogous as potent non-nucleoside reverse-transcriptase inhibitors

NASA Astrophysics Data System (ADS)

Nazar, Muhammad Faizan; Abdullah, Muhammad Imran; Badshah, Amir; Mahmood, Asif; Rana, Usman Ali; Khan, Salah Ud-Din

2015-04-01

The chalcones core in compounds is advantageously chosen effective synthons, which offer exciting perspectives in biological and pharmacological research. The present study reports the successful development of eight new cyclohexenone based anti-reverse transcriptase analogous using rational drug design synthesis principles. These new cyclohexenone derivatives (CDs) were synthesized by following a convenient route of Robinson annulation, and the molecular structure of these CDs were later confirmed by various analytical techniques such as 1H NMR, 13C NMR, FT-IR, UV-Vis spectroscopy and mass spectrometry. All the synthesized compounds were screened theoretically and experimentally against reverse transcriptase (RT) and found potentially active reverse transcriptase (RT) inhibitors. Of the compounds studied, the compound 2FC4 showed high interaction with RT at non-nucleoside binding site, contributing high free binding energy (ΔG -8.01 Kcal) and IC50 (0.207 μg/ml), respectively. Further results revealed that the compounds bearing more halogen groups, with additional hydrophobic character, offered superior anti-reverse transcriptase activity as compared to rest of compounds. It is anticipate that the present study would be very useful for the selection of potential reverse transcriptase inhibitors featuring inclusive pharmacological profiles.

Crystal structure, spectral property, antimicrobial activity and DFT calculation of N-(coumarin-3-yl)-N‧-(2-amino-5-phenyl-1,3,4-thiadiazol-2-yl) urea

NASA Astrophysics Data System (ADS)

Zhang, Hong-Song; Zhang, Kong-Yan; Chen, Li-Chuan; Li, Yao-Xin; Chai, Lan-Qin

2017-10-01

N-(coumarin-3-yl)-N‧-(2-amino-5-phenyl-1,3,4-thiadiazol-2-yl) urea was synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR, UV-Vis and emission spectroscopy, as well as by single-crystal X-ray diffraction. X-ray crystallographic analyses have indicated that the crystal structure consists of two dimethyl sulfoxide (DMSO) solvent molecules and the structural geometry of DMSO is a trigonal pyramid in shape. In the crystal structure, a self-assembling two-dimensional (2-D) layer supramolecular architecture is formed through intermolecular hydrogen bonds, Cdbnd O···π (thiadiazole ring) and π···π stacking interactions. The geometry of the compound has been optimized by the DFT method and the results are compared with the X-ray diffraction data. The electronic transitions and spectral features of the compound were carried out by using DFT/B3LYP method. In addition, the antimicrobial activity was also studied, and the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and HOMO-LUMO gap were also calculated.

A detailed experimental and theoretical study of two novel substituted trifluoromethylchromones. The influence of the bulky bromine atom on the crystal packing.

PubMed

Alcívar León, C D; Echeverría, G A; Piro, O E; Ulic, S E; Jios, J L

2015-02-05

The new 3-methyl-2-trifluoromethylchromone (1) and 3-bromomethyl-2-trifluoromethylchromone (2) compounds were synthesized and characterized by vibrational (IR, Raman), UV-Vis and NMR ((1)H, (13)C and (19)F) spectroscopy and MS spectrometry. The crystal structures of 1 and 2 were determined by X-ray diffraction methods. Both compounds crystallize in the monoclinic P21/c space group with Z=4 molecules per unit cell. The structures were solved from 1423 (1) and 1856 (2) reflections with I>2σ (I) and refined by full-matrix least-squares to agreement R1-values of 0.0403 (1) and 0.0554 (2). Because of π-bonding delocalization, the organic molecular skeletons are planar and the molecular bonding structures can be described by formally single, double and resonant bonds. In 2, the CF3 group revealed a strong rotational disorder around the CCF3 bond, which could be explained in terms of four split positions with about uniform angular distribution. The vibrational, electronic and NMR, spectra were discussed and assigned with the assistance of DFT calculations. Copyright © 2014 Elsevier B.V. All rights reserved.

The first naphthosemiquinone complex of K+ with vitamin K3 analog: Experiment and density functional theory

NASA Astrophysics Data System (ADS)

Kathawate, Laxmi; Gejji, Shridhar P.; Yeole, Sachin D.; Verma, Prakash L.; Puranik, Vedavati G.; Salunke-Gawali, Sunita

2015-05-01

Synthesis and characterization of potassium complex of 2-hydroxy-3-methyl-1,4-naphthoquinone (phthiocol), the vitamin K3 analog, has been carried out using FT-IR, UV-Vis, 1H and 13C NMR, EPR, cyclic voltammetry and single crystal X-ray diffraction experiments combined with the density functional theory. It has been observed that naphthosemiquinone binds to two K+ ions extending the polymeric chain through bridging oxygens O(2) and O(3). The crystal network possesses hydrogen bonding interactions from coordinated water molecules showing water channels along the c-axis. 13C NMR spectra revealed that the complexation of phthiocol with potassium ion engenders deshielding of C(2) signals, which appear at δ = ∼14.6 ppm whereas those of C(3) exhibit up-field signals near δ ∼ 6.9 ppm. These inferences are supported by the M06-2x based density functional theory. Electrochemical experiments further suggest that reduction of naphthosemiquinone results in only a cathodic peak from catechol. A triplet state arising from interactions between neighboring phthiocol anion lead to a half field signal at g = 4.1 in the polycrystalline X-band EPR spectra at 133 K.

Tannins of tamarind seed husk: preparation, structural characterization, and antioxidant activities.

PubMed

Sinchaiyakit, Puksiri; Ezure, Yohji; Sriprang, Sarin; Pongbangpho, Supakorn; Povichit, Nasapon; Suttajit, Maitree

2011-06-01

The high content (about 39%) of polymeric tannins in tamarind (Tamarindus indica L.) seed husk (TSH) was demonstrated, and an extract (crude TSE) with a high content (about 94%) of polymeric tannins was prepared from TSH with a one pot extraction using ethanol/water (3:2, v/v). The crude TSE was further purified with Sephadex LH20 to give one fraction (metTSE) eluted with methanol/water (3:2, v/v) and another (acTSE) eluted with acetone/water (3:2, v/v). The tannins of acTSE were established as polymeric proanthocyanidins (PA) by 13C NMR spectroscopy; this was further confirmed by IR and UV spectroscopy, n-BuOH/HCl and vanillin assays, and from HPLC pattern. The ratio of procyanidins to prodelphinidins was 2:3, and the average degree of polymerization of acTSE was 7. Galloylated flavan-3-ols were not detected in acTSE. The main ingredients of metTSE were confirmed to be polymeric PA by 13C NMR spectroscopy. The antioxidant activities using DPPH and ABTS assays were investigated. The IC50 values of acTSE were 4.2 +/- 0.2 (DPPH assay) and 6.2 +/- 0.3 microg/mL (ABTS assay).

Comparative study of lignin characteristics from wheat straw obtained by soda-AQ and kraft pretreatment and effect on the following enzymatic hydrolysis process

DOE PAGES

Yang, Haitao; Xie, Yimin; Zheng, Xing; ...

2016-02-18

With this study, to understand the structural changes of lignin after soda-AQ and kraft pretreatment, milled straw lignin, black liquor lignin and residual lignin extracted from wheat straw were characterized by FT-IR, UV, GPC and NMR. The results showed that the main lignin linkages were β-aryl ether substructures (β-O-4'), followed by phenylcoumaran (β-5') and resinol (β-β') substructures, while minor content of spirodienone (β-1'), dibenzodioxocin (5-5') and α,β-diaryl ether linkages were detected as well. After pretreatment, most lignin inter-units and lignin-carbohydrate complex (LCC) linkages were degraded and dissolved in black liquor, with minor amount left in residual pretreated biomass. In addition,more » through quantitative 13C and 2D-HSQC NMR spectral analysis, lignin and LCC were found to be more degraded after kraft pretreatment than soda-AQ pretreatment. Furthermore, the subsequent enzymatic hydrolysis results showed that more cellulose in wheat straw was converted to glucose after kraft pretreatment, indicating that LCC linkages were important in the enzymatic hydrolysis process.« less

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate.

PubMed

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines' couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, (1)H-NMR, (13)C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16-64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate

PubMed Central

Sopbue Fondjo, Emmanuel; Sorel, Djeukoua Dimo Kamal; Jean-de-Dieu, Tamokou; Joseph, Tsemeugne; Sylvian, Kouamo; Doriane, Ngouanet; Rodolphe, Chouna Jean; Pepin, Nkeng-Efouet-Alango; Jules-Roger, Kuiate; Arnaud, Ngongang Ndjintchui; Lucas, Sondengam Beibam

2016-01-01

The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants. PMID:27583034

Extending Supernova Spectral Templates for Next Generation Space Telescope Observations

NASA Astrophysics Data System (ADS)

Roberts-Pierel, Justin; Rodney, Steven A.; Steven Rodney

2018-01-01

Widely used empirical supernova (SN) Spectral Energy Distributions (SEDs) have not historically extended meaningfully into the ultraviolet (UV), or the infrared (IR). However, both are critical for current and future aspects of SN research including UV spectra as probes of poorly understood SN Ia physical properties, and expanding our view of the universe with high-redshift James Webb Space Telescope (JWST) IR observations. We therefore present a comprehensive set of SN SED templates that have been extended into the UV and IR, as well as an open-source software package written in Python that enables a user to generate their own extrapolated SEDs. We have taken a sampling of core-collapse (CC) and Type Ia SNe to get a time-dependent distribution of UV and IR colors (U-B,r’-[JHK]), and then generated color curves are used to extrapolate SEDs into the UV and IR. The SED extrapolation process is now easily duplicated using a user’s own data and parameters via our open-source Python package: SNSEDextend. This work develops the tools necessary to explore the JWST’s ability to discriminate between CC and Type Ia SNe, as well as provides a repository of SN SEDs that will be invaluable to future JWST and WFIRST SN studies.

Identification of the silver state in the framework of Ag-containing zeolite by XRD, FTIR, photoluminescence, 109Ag NMR, EPR, DR UV-vis, TEM and XPS investigations.

PubMed

Popovych, Nataliia; Kyriienko, Pavlo; Soloviev, Sergiy; Baran, Rafal; Millot, Yannick; Dzwigaj, Stanislaw

2016-10-26

Silver has been identified in the framework of Ag x SiBEA zeolites (where x = 3-6 Ag wt%) by the combined use of XRD, 109 Ag MAS NMR, FTIR, diffuse reflectance UV-visible, EPR and XPS spectroscopy. The incorporation of Ag ions into the framework of SiBEA zeolite has been evidenced by XRD. The consumption of OH groups as a result of their reaction with the silver precursor has been monitored by FTIR and photoluminescence spectroscopy. The changes in the silver state as a function of Ag content and thermal and hydrogen treatment at 573 K have been identified by 109 Ag MAS NMR, EPR, DR UV-visible, TEM and XPS investigations. The acidity of AgSiBEA has been investigated by FTIR spectroscopy of adsorbed CO and pyridine used as probe molecules.

Towards label-free and site-specific probing of the local pH in proteins: pH-dependent deep UV Raman spectra of histidine and tyrosine

NASA Astrophysics Data System (ADS)

Bröermann, Andreas; Steinhoff, Heinz-Jürgen; Schlücker, Sebastian

2014-09-01

The site-specific pH is an experimental probe for assessing models of structural folding and function of a protein as well as protein-protein and protein-ligand interactions. It can be determined by various techniques such as NMR, FT-IR, fluorescence and EPR spectroscopy. The latter require the use of external labels, i.e., employ pH-dependent dyes and spin labels, respectively. In this contribution, we outline an approach to a label-free and site-specific method for determining the local pH using deep ultraviolet resonance Raman (UVRR) spectroscopic fingerprints of the aromatic amino acids histidine and tyrosine in combination with a robust algorithm that determines the pH value using three UVRR reference spectra and without prior knowledge of the pKa.

Simultaneous Chemical and Optical Patterning of Polyacrylonitrile Film by Vapor-Based Reaction.

PubMed

Shin, Jae-Won; Lee, Choonghyeon; Cha, Sang-Ho; Jang, Jyongsik; Lee, Kyung Jin

2015-06-01

The surface of polyacrylonitrile (PAN) film is treated with ethyleneamines (EDA) in a simple chemical vapor phase reaction. Successful introduction of amine functional groups on the cyano group of PAN backbone is verified by FT-IR and NMR measurements. Further UV-vis and photoluminescence analyses show a red shift of the emission peak after repeated EDA treatment, which might be attributed to the formation of imine conjugation from newly formed carbon-nitrogen bonds on the PAN backbone. Further confocal laser scanning microscopy reveals that selective patterning of EDA on PAN films is possible via local polydimethylsiloxane masking. The results indicate that both chemical and optical patterning on PAN film can be realized via a single reaction and show the potential of this novel methodology in selective patterning. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Zn(2+)-responsive highly sensitive fluorescent probe and 1D coordination polymer based on a coumarin platform.

PubMed

Kumar, Virendra; Kumar, Ajit; Diwan, Uzra; Upadhyay, K K

2013-09-28

A coumarin-based Schiff base (receptor 1) exhibited fluorescence enhancement selectively with Zn(2+) at a nanomolar level in near-aqueous medium (EtOH-H2O; 1:1, v/v). The response was instantaneous with a detection limit of 3.26 × 10(-9) M. The sensing event is supposed to incorporate a combinational effect of intramolecular charge transfer (ICT), chelation-enhanced fluorescence (CHEF) and C[double bond, length as m-dash]N isomerization mechanisms. Various spectroscopic methods, viz. IR, UV-visible, fluorescence and NMR in association with single crystal XRD studies, were used for thorough investigation of the structure of receptor 1 as well as of the sensing event. The Zn(2+) complex of receptor 1 exhibited a very nice 1D chain coordination polymeric framework in its single crystal XRD.

Synthesis, characterization and investigation of electrochemical and spectroelectrochemical properties of peripherally tetra 4-phenylthiazole-2-thiol substituted metal-free, zinc(II), copper(II) and cobalt(II) phthalocyanines

NASA Astrophysics Data System (ADS)

Demirbaş, Ümit; Akçay, Hakkı Türker; Koca, Atıf; Kantekin, Halit

2017-08-01

In this study novel peripherally tetra 4-phenylthiazole-2-thiol substituted metal-free phthalocyanine (4) and its zinc(II) (5), copper(II) (6) and cobalt(II) (7) derivatives were synthesized and characterized by a combination of various spectroscopic techniques such as FT-IR, 1H-NMR, UV-vis and MALDI-TOF mass. Electrochemical characterizations of metallo-phthalocyanine complexes were conducted by voltammetric and in situ spectroelectrochemical measurements. CoIIPc went [CoIIPc-2]/[CoIPc-2]1-, [CoIPc-2]1-/[CoIPc-3]2-, [CoIPc-3]2-/[CoIPc-4]3- and [CoIIPc-2]/[CoIIPc-2]1+ reduction and oxidation processes respectively. Differently ZnIIPc only showed four ligand-based reductions and two ligand based oxidation processes.

LC-MS guided isolation of diterpenoids from Sapium insigne with α-glucosidase inhibitory activities.

PubMed

Yan, De-Xiu; Geng, Chang-An; Yang, Tong-Hua; Huang, Xiao-Yan; Li, Tian-Ze; Gao, Zhen; Ma, Yun-Bao; Peng, Hua; Zhang, Xue-Mei; Chen, Ji-Jun

2018-04-08

Ten new (1-10) and ten known (11-20) diterpenoids involving ent-atisane, ent-seco-atisane, ent-kaurane and ent-seco-kaurane types were isolated from Sapium insigne under the guidance of LCMS-IT-TOF analyses. Their structures were characterized by extensive spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR). A putative biosynthetic pathway was proposed for ent-seco-atisane diterpenoids. Their inhibitory activities on α-glucosidase in vitro were tested for the first time. Compound 4 showed moderate inhibitory effect on α-glucosidase with an IC 50 value of 0.34 mM via a noncompetitive inhibition mechanism (K i  = 0.27 mM). The preliminary structure-activity relationships of the ent-atisane diterpenoids inhibiting α-glucosidase were discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

The first octahedral cluster complexes with terminal formate ligands: synthesis, structure, and properties of K4[Re6S8(HCOO)6] and Cs4[Re6S8(HCOO)6].

PubMed

Brylev, Konstantin A; Mironov, Yuri V; Kozlova, Svetlana G; Fedorov, Vladimir E; Kim, Sung-Jin; Pietzsch, Hans-Jürgen; Stephan, Holger; Ito, Akitaka; Ishizaka, Shoji; Kitamura, Noboru

2009-03-02

The hexarhenium anionic cluster complex with terminal formate ligands [Re6S8(HCOO)6]4- was obtained by the room-temperature reaction between [Re6S8(OH)6]4- and formic acid in an aqueous solution. The cluster was crystallized as a potassium or cesium salt and characterized by X-ray single-crystal diffraction and elemental analyses, IR, 1H NMR, UV/vis, and luminescence spectroscopies. In particular, the emission quantum yield of the potassium salt of the Re6 cluster anion in the solid phase was determined for the first time. The electronic structures of [Re6S8(HCOO)6]4- and [Re6S8(OH)6]4- were also elucidated by DFT calculations.

pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.

PubMed

Adachi, Naoya; Kaneko, Yuki; Sekiguchi, Kazuki; Sugiyama, Hiroki; Sugeno, Masafumi

2015-12-01

Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing. Copyright © 2015 John Wiley & Sons, Ltd.

Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

NASA Astrophysics Data System (ADS)

Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

2016-02-01

Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

Synthesis, characterization and calculated non-linear optical properties of two new chalcones

NASA Astrophysics Data System (ADS)

Singh, Ashok Kumar; Saxena, Gunjan; Prasad, Rajendra; Kumar, Abhinav

2012-06-01

Two new chalcones viz 3-(4-(benzyloxy)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (1) and 3-(4-chlorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (2) have been prepared and characterized by micro analyses, 1H NMR, IR, UV-Vis spectroscopy and single crystal X-ray. The first static hyperpolarizability (β) for both the compounds has been investigated by density functional theory (DFT). Also, the solvent-induced effects on the non-linear optical properties (NLO) were studied by using self-consistent reaction field (SCRF) method. As the solvent polarity increases, the β value increases monotonically. The electronic absorption bands of both 1 and 2 have been assigned by time dependent density functional theory (TD-DFT). Both the compounds displayed better non-linear optical (NLO) responses than the standard p-nitroaniline (pNA).

Synthesis, photoluminescent, antibacterial activities and theoretical studies of 4-hydroxycoumarin derivatives

NASA Astrophysics Data System (ADS)

Li, Jing; Hou, Zheng; Li, Fen; Zhang, Zi-dan; Zhou, Ying; Luo, Xiao-xing; Li, Ming-kai

2014-10-01

Two new biscoumarin and epoxydicoumarin derivatives, namely, 3,3‧-(4-di-p-tolyl-amino-benzylidene)-bis-(4-hydroxycoumarin) (DBH) and 9-(4-di-p-tolyl-amino-phenyl)-1,8-dioxo-9H-dibenzo[c,h]-2,7,10-trioxanthene (DDT), were synthesized and characterized via IR, 1H NMR, HRMS, single crystal X-ray crystallography and UV-vis absorption spectra. The fluorescence behaviors of DBH and DDT in dichloromethane solutions were observed. The in vitro antibacterial activity of DBH and DDT against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC) was evaluated by observing the minimum inhibitory concentration. The results showed that compared with compound DDT, DBH exhibited better potent antibacterial activity.

Synthesis and characterization of a novel inorganic-organic hybrid material based on polyoxometalates and dicyclohexylcarbodiimide

NASA Astrophysics Data System (ADS)

Huang, Bo; Hu, Xiaokang; Hu, Xunliang; Wang, Nan; Yang, Kang; Xiao, Zicheng; Wu, Pingfan

2017-12-01

Towards design and synthesis of bulky molecules and molecular machines, we reported a new inorganic-organic hybrid material based on polyoxometalates and 1, 3-dicyclohexylcarbodiimide (DCC): (Bu4N)2[V6O13{(OCH2)3CCH2OOCCH2CH2CON(C6H11)CONHC6H11}2]. The hybrid was characterized by FT-IR, 1H NMR, UV-Vis, ESI-MS, and the structure of the compound was determined through single-crystal X-ray diffraction. There was an interesting supramolecular assembly in the hybrid material through intermolecular hydrogen bonding, and each cyclohexyl in the polymer looks like one of blades in the propeller. Furthermore, the thermal stability of the hybrid was tested by TGA analyses, and the electrochemical property has also been studied by cyclic voltammogram.

Maillard reaction products from chitosan-xylan ionic liquid solution.

PubMed

Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

2013-10-15

A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Complexation of nitrogen and sulphur donor Schiff's base ligand to Cr(III) and Ni(II) metal ions: Synthesis, spectroscopic and antipathogenic studies

NASA Astrophysics Data System (ADS)

Sharma, Amit Kumar; Chandra, Sulekh

2011-01-01

2,6-Diacetyl pyridine based ligand was synthesized by the reaction of 2,6-diacetyl pyridine with thiocarbohydrazide in presence of acetic acid. The coordination compounds with Cr(III) and Ni(II) metal ions having [Cr(L)X]X 2 and [Ni(L)X]X compositions (where L = ligand and X = NO 3-, Cl - and CH 3COO -) were synthesized and characterized by physicochemical and spectral studies. The studies like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV-Vis, NMR, mass and EPR reveal that the complexes are octahedral. The compounds were examined against the pathogenic fungal and bacterial strains like Alternaria brassicae, Aspergillus niger, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa. A. niger causes the diseases Apergillosis and Otomycosis in humans.

Spectral and in vitro antimicrobial properties of 2-oxo-4-phenyl-6-styryl-1,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid transition metal complexes

NASA Astrophysics Data System (ADS)

Dhankar, Raksha P.; Rahatgaonkar, Anjali M.; Chorghade, Mukund S.; Tiwari, Ashutosh

2-oxo-4-phenyl-6-styryl-1,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid (ADP) was complexed with acetates of Mn(II), Ni(II), Cu(II) and Zn(II). The structures of the ligand and its metal complexes were characterized by microanalysis, IR, NMR, UV-vis spectroscopy, magnetic susceptibility and TGA-DTA analyses. Octahedral and square planar geometries were suggested for the complexes in which the central metal ion coordinated with sbnd O donors of ligand and acetate ions. Each ligand binds the metal using carboxylate oxygens. The ligand and complexes were evaluated for their antimicrobial activities against different species of pathogenic bacteria and fungi. The present novel pyrimidine containing complexes could constitute a new group of antibacterial and antifungal agents.

Synthesis, spectroscopic characterization and structural investigations of new adduct compound of carbazole with picric acid: DNA binding and antimicrobial studies.

PubMed

Saravanabhavan, Munusamy; Sathya, Krishnan; Puranik, Vedavati G; Sekar, Marimuthu

2014-01-24

Carbazole picrate (CP), a new organic compound has been synthesized, characterized by various analytical and spectroscopic technique such as FT-IR, UV-Vis, (1)H and (13)C NMR spectroscopy. An orthorhombic geometry was proposed based on single crystal XRD study. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it was stable up to 170°C. Further, the newly synthesized title compound was tested for its in vitro antibacterial and antifungal activity against various bacterial and fungal species. Also, the compound was tested for its binding activity with Calf thymus (CT) DNA and the results show a considerable interaction between CP and CT-DNA. Copyright © 2013 Elsevier B.V. All rights reserved.

Dual fluorescence of N-phenylanthranilic acid: Effect of solvents, pH and beta-cyclodextrin.

PubMed

Rajendiran, N; Balasubramanian, T

2007-11-01

Spectral characteristics of N-phenylanthranilic acid (NPAA) have been studied in different solvents, pH and beta-cyclodextrin (beta-CD) and compared with anthranilic acid (2-aminobenzoic acid, 2ABA). In all solvents a dual fluorescence is observed in NPAA, whereas 2ABA gives single emission. Combining the results observed in the absorption, fluorescence emission and fluorescence excitation spectra, it is found that strong intramolecular hydrogen bonding (IHB) interactions present in NPAA molecule. The inclusion complex of NPAA with beta-CD is analysed by UV-vis, fluorimetry, FT-IR, (1)H NMR, scanning electron microscope and AM 1 method. The above spectral studies show that NPAA forms a 1:1 inclusion complex with beta-CD and COOH group present in the beta-CD cavity. A mechanism is proposed to explain the inclusion process.

Dual fluorescence of N-phenylanthranilic acid: Effect of solvents, pH and β-cyclodextrin

NASA Astrophysics Data System (ADS)

Rajendiran, N.; Balasubramanian, T.

2007-11-01

Spectral characteristics of N-phenylanthranilic acid (NPAA) have been studied in different solvents, pH and β-cyclodextrin (β-CD) and compared with anthranilic acid (2-aminobenzoic acid, 2ABA). In all solvents a dual fluorescence is observed in NPAA, whereas 2ABA gives single emission. Combining the results observed in the absorption, fluorescence emission and fluorescence excitation spectra, it is found that strong intramolecular hydrogen bonding (IHB) interactions present in NPAA molecule. The inclusion complex of NPAA with β-CD is analysed by UV-vis, fluorimetry, FT-IR, 1H NMR, scanning electron microscope and AM 1 method. The above spectral studies show that NPAA forms a 1:1 inclusion complex with β-CD and COOH group present in the β-CD cavity. A mechanism is proposed to explain the inclusion process.

Vitiquinolone--a quinolone alkaloid from Hibiscus vitifolius Linn.

PubMed

Ramasamy, D; Saraswathy, A

2014-02-15

Phytochemical investigations of the powdered root of Hibiscus vitifolius Linn. (Malvaceae) was extracted successively with n-hexane and chloroform. Analysis of the n-hexane extract by GC-MS led to the identification of twenty-six components by comparison of their mass spectra with GC-MS library data. A novel quinolone alkaloid, vitiquinolone (5) together with eight known compounds viz. β-Amyrin acetate (1), n-octacosanol (2), β-Amyrin (3), stigmasterol (4), xanthyletin (6), alloxanthoxyletin (7), xanthoxyletin (8) and betulinic acid (9) were isolated from chloroform extract by column chromatography over silica gel. The structure of vitiquinolone was established on the basis of spectroscopic methods including UV, IR, 1D, 2D NMR and ESI-MS. The known compounds were identified on the basis of their physical and spectroscopic data as reported in the literature. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physicochemical characterization of ezetimibe and its impurities

NASA Astrophysics Data System (ADS)

Filip, Katarzyna; Bańkowski, Krzysztof; Sidoryk, Katarzyna; Zagrodzka, Joanna; Łaszcz, Marta; Trzcińska, Kinga; Szyprowska, Anna; Cmoch, Piotr; Maruszak, Wioleta

2011-04-01

The physicochemical characterization of major degradation and process-related impurities associated with the synthesis of ezetimibe was performed. The possibility of forming the undesirable ( R, R, S) stereoisomer of ezetimibe has been mentioned in literature (Vinod KK, Suhail A, Bhupendra T, Nitin G US 2010/0010212 A1, Ind-Swift Laboratories Limited WO 2008/096372), but no study of its structure determination has been published yet. This paper discusses the structure elucidation of the ( R, R, S) stereoisomer as well as ezetimibe degradation product on the bases of NMR, IR and MS data. Other potential impurities of ezetimibe are also described. A selective and stability-indicating high-performance liquid chromatography method with dual UV detection was developed for the determination of chemical and stereochemical purity of ezetimibe. The characterization of particle size and shape for ezetimibe and its stereoisomer is also described.

119Sn-NMR investigations on superconducting Ca 3Ir 4Sn 13: Evidence for multigap superconductivity

DOE PAGES

Sarkar, R.; Petrovic, C.; Bruckner, F.; ...

2015-09-25

In this study, we report bulk superconductivity (SC) in Ca 3Ir 4Sn 13 by means of 119Sn nuclear magnetic resonance (NMR) experiments. Two classical signatures of BCS superconductivity in spin-lattice relaxation rate (1/T 1), namely the Hebel–Slichter coherence peak just below the T c, and the exponential decay in the superconducting phase, are evident. The noticeable decrease of 119Sn Knight shift below T c indicates spin-singlet superconductivity. The temperature dependence of the spin-lattice relaxation rate 119(1/T 1) is convincingly described by the multigap isotropic superconducting gap. NMR experiments do not witness any sign of enhanced spin fluctuations.

Quantum mechanical study of the structure and spectroscopic (FT-IR, FT-Raman, 13C, 1H and UV), first order hyperpolarizabilities, NBO and TD-DFT analysis of the 4-methyl-2-cyanobiphenyl

NASA Astrophysics Data System (ADS)

Sebastian, S.; Sundaraganesan, N.; Karthikeiyan, B.; Srinivasan, V.

2011-02-01

The Fourier transform infrared (FT-IR) and FT-Raman of 4-methyl-2-cyanobiphenyl (4M2CBP) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated with the help of density functional theory (DFT) method. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge including atomic orbital (GIAO) method. The first order hyperpolarizability ( β0) of this novel molecular system and related properties ( β, α0 and Δ α) of 4M2CBP are calculated using HF/6-311G(d,p) method on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the σ* and π* antibonding orbitals and second order delocalization energies ( E2) confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. UV-vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT) approach. Finally the calculations results were applied to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra.

Synthesis, Characterization, and BSA-Binding Studies of Novel Sulfonated Zinc-Triazine Complexes

PubMed Central

Abeydeera, Nalin; Perera, Inoka C.

2018-01-01

Four Zn(II) complexes containing a pyridyl triazine core (L1 = 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5′,5″-disulfonic acid disodium salt and L2 = 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4″-disulfonic acid sodium salt) were synthesized, and their chemical formulas were finalized as [Zn(L1)Cl2]·5H2O·ZnCl2 (1), [Zn(L1)2Cl2]·4H2O·2CH3OH (2), [Zn(L2)Cl2]·3H2O·CH3OH (3), and [Zn(L2)2Cl2] (4). The synthesized complexes are water soluble, making them good candidates for biological applications. All four complexes have been characterized by elemental analysis and 1H NMR, IR, and UV-Vis spectroscopy. The IR stretching frequency of N=N and C=N bonds of complexes 1–4 have shifted to lower frequencies in comparison with free ligands, and a bathochromic shift was observed in UV-Vis spectra of all four complexes. The binding studies of ligands and complexes 1–4 with bovine serum albumin (BSA) resulted binding constants (K b) of 3.09 × 104 M−1, 12.30 × 104 M−1, and 16.84 × 104 M−1 for ferene, complex 1, and complex 2, respectively, indicating potent serum distribution via albumins. PMID:29670646

Synthesis, characterization, nucleic acid interactions and photoluminescent properties of methaniminium hydrazone Schiff base and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes

NASA Astrophysics Data System (ADS)

Sennappan, M.; Murali Krishna, P.; Hosamani, Amar A.; Hari Krishna, R.

2018-07-01

An environmental benign and efficient reaction was carried out via amine exchange and condensation reaction in water and methanol mixture (3:1) and absence of catalyst between 1-[3-(2-hydroxy benzylidene)amine)phenyl]ethanone and benzhydrazide yields methaniminium hydrazone Schiff base in high yield. The prepared ligand was structurally characterized by using single crystal XRD, elemental analysis and spectroscopy (UV-Vis, FT-IR, LC-MS and NMR) techniques. The crystal data indicates the ligand crystallizes in orthorhombic system with Pna21 space group. Further, the ligand was used in synthesis of mononuclear Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes and were characterized by elemental analysis, magnetic moment and spectroscopy (UV-Vis, FT-IR and ESR) studies. The spectral data showed that ligand is coordinated to the metal ion through azomethine nitrogen and methaniminium nitrogen. The DNA binding absorption titrations reveals that, ligand, L and its metal complexes, 1-6 are avid binders to CT- DNA. The apparent binding constant values of compounds are in the order of 106 M-1. The nuclease activity of ligand, L and its metal complexes, 1-6 were investigated by gel electrophoresis method using pUC18 DNA. The photoluminescent properties of the methaniminium hydrazone ligand, L and its various metal complexes, 1-6 were investigated. The emission spectra of both ligand (L) and metal complexes (1-6) exhibits emission in the range of blue to red.

Study of conformational stability, structural, electronic and charge transfer properties of cladrin using vibrational spectroscopy and DFT calculations.

PubMed

Singh, Swapnil; Singh, Harshita; Srivastava, Anubha; Tandon, Poonam; Sinha, Kirti; Bharti, Purnima; Kumar, Sudhir; Kumar, Padam; Maurya, Rakesh

2014-11-11

In the present work, a detailed conformational study of cladrin (3-(3,4-dimethoxy phenyl)-7-hydroxychromen-4-one) has been done by using spectroscopic techniques (FT-IR/FT-Raman/UV-Vis/NMR) and quantum chemical calculations. The optimized geometry, wavenumber and intensity of the vibrational bands of the cladrin in ground state were calculated by density functional theory (DFT) employing 6-311++G(d,p) basis sets. The study has been focused on the two most stable conformers that are selected after the full geometry optimization of the molecule. A detailed assignment of the FT-IR and FT-Raman spectra has been done for both the conformers along with potential energy distribution for each vibrational mode. The observed and scaled wavenumber of most of the bands has been found to be in good agreement. The UV-Vis spectrum has been recorded and compared with calculated spectrum. In addition, 1H and 13C nuclear magnetic resonance spectra have been also recorded and compared with the calculated data that shows the inter or intramolecular hydrogen bonding. The electronic properties such as HOMO-LUMO energies were calculated by using time-dependent density functional theory. Molecular electrostatic potential has been plotted to elucidate the reactive part of the molecule. Natural bond orbital analysis was performed to investigate the molecular stability. Non linear optical property of the molecule have been studied by calculating the electric dipole moment (μ) and the first hyperpolarizability (β) that results in the nonlinearity of the molecule. Copyright © 2014 Elsevier B.V. All rights reserved.

Boronate ligands in materials: determining their local environment by using a combination of IR/solid-state NMR spectroscopies and DFT calculations.

PubMed

Sene, Saad; Reinholdt, Marc; Renaudin, Guillaume; Berthomieu, Dorothée; Zicovich-Wilson, Claudio M; Gervais, Christel; Gaveau, Philippe; Bonhomme, Christian; Filinchuk, Yaroslav; Smith, Mark E; Nedelec, Jean-Marie; Bégu, Sylvie; Mutin, P Hubert; Laurencin, Danielle

2013-01-14

Boronic acids (R-B(OH)(2)) are a family of molecules that have found a large number of applications in materials science. In contrast, boronate anions (R-B(OH)(3)(-)) have hardly been used so far for the preparation of novel materials. Here, a new crystalline phase involving a boronate ligand is described, Ca[C(4)H(9)-B(OH)(3)](2), which is then used as a basis for the establishment of the spectroscopic signatures of boronates in the solid state. The phase was characterized by IR and multinuclear solid-state NMR spectroscopy ((1)H, (13)C, (11)B and (43)Ca), and then modeled by periodic DFT calculations. Anharmonic OH vibration frequencies were calculated as well as NMR parameters (by using the Gauge Including Projector Augmented Wave--GIPAW--method). These data allow relationships between the geometry around the OH groups in boronates and the IR and (1)H NMR spectroscopic data to be established, which will be key to the future interpretation of the spectra of more complex organic-inorganic materials containing boronate building blocks. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spatially resolved star formation and dust attenuation in Mrk 848: Comparison of the integral field spectra and the UV-to-IR SED

NASA Astrophysics Data System (ADS)

Yuan, Fang-Ting; Argudo-Fernández, María; Shen, Shiyin; Hao, Lei; Jiang, Chunyan; Yin, Jun; Boquien, Médéric; Lin, Lihwai

2018-05-01

We investigate the star formation history and the dust attenuation in the galaxy merger Mrk 848. Thanks to the multiwavelength photometry from the ultraviolet (UV) to the infrared (IR), and MaNGA's integral field spectroscopy, we are able to study this merger in a detailed way. We divide the whole merger into the core and tail regions, and fit both the optical spectrum and the multi-band spectral energy distribution (SED) to models to obtain the star formation properties for each region respectively. We find that the color excess of stars in the galaxy E(B-V)sSED measured with the multi-band SED fitting is consistent with that estimated both from the infrared excess (the ratio of IR to UV flux) and from the slope of the UV continuum. Furthermore, the reliability of the E(B-V)sSED is examined with a set of mock SEDs, showing that the dust attenuation of the stars can be well constrained by the UV-to-IR broadband SED fitting. The dust attenuation obtained from optical continuum E(B-V)sspec is only about half of E(B-V)sSED. The ratio of the E(B-V)sspec to the E(B-V)g obtained from the Balmer decrement is consistent with the local value (around 0.5). The difference between the results from the UV-to-IR data and the optical data is consistent with the picture that younger stellar populations are attenuated by an extra dust component from the birth clouds compared to older stellar populations which are only attenuated by the diffuse dust. Both with the UV-to-IR SED fitting and the spectral fitting, we find that there is a starburst younger than 100 Myr in one of the two core regions, consistent with the scenario that the interaction-induced gas inflow can enhance the star formation in the center of galaxies.

Molecular heterogeneous catalysts derived from bipyridine-based organosilica nanotubes for C–H bond activation† †Electronic supplementary information (ESI) available: Experimental details, material characterization data, catalytic measurement details. See DOI: 10.1039/c7sc00713b Click here for additional data file.

PubMed Central

Zhang, Shengbo; Wang, Hua; Li, Mei; Han, Jinyu

2017-01-01

Heterogeneous metal complex catalysts for direct C–H activation with high activity and durability have always been desired for transforming raw materials into feedstock chemicals. This study described the design and synthesis of one-dimensional organosilica nanotubes containing 2,2′-bipyridine (bpy) ligands in the framework (BPy-NT) and their post-synthetic metalation to provide highly active and robust molecular heterogeneous catalysts. By adjusting the ratios of organosilane precursors, very short BPy-NT with ∼50 nm length could be controllably obtained. The post-synthetic metalation of bipyridine-functionalized nanotubes with [IrCp*Cl(μ-Cl)]2 (Cp* = η5-pentamethylcyclopentadienyl) and [Ir(cod)(OMe)]2 (cod = 1,5-cyclooctadiene) afforded solid catalysts, IrCp*-BPy-NT and Ir(cod)-BPy-NT, which were utilized for C–H oxidation of heterocycles and cycloalkanes as well as C–H borylation of arenes. The cut-short nanotube catalysts displayed enhanced activities and durability as compared to the analogous homogeneous catalysts and other conventional heterogeneous catalysts, benefiting from the isolated active sites as well as the fast transport of substrates and products. After the reactions, a detailed characterization of Ir-immobilized BPy-NT via TEM, SEM, nitrogen adsorption, UV/vis, XPS, and 13C CP MAS NMR indicated the molecular nature of the active species as well as stable structures of nanotube scaffolds. This study demonstrates the potential of BPy-NT with a short length as an integration platform for the construction of efficient heterogeneous catalytic systems for organic transformations. PMID:28970878

Design, synthesis, spectral characterization, DNA interaction and biological activity studies of copper(II), cobalt(II) and nickel(II) complexes of 6-amino benzothiazole derivatives

NASA Astrophysics Data System (ADS)

Daravath, Sreenu; Kumar, Marri Pradeep; Rambabu, Aveli; Vamsikrishna, Narendrula; Ganji, Nirmala; Shivaraj

2017-09-01

Two novel Schiff bases, L1 = (2-benzo[d]thiazol-6-ylimino)methyl)-4,6-dichlorophenol), L2 = (1-benzo[d]thiazol-6-ylimino)methyl)-6-bromo-4-chlorophenol) and their bivalent transition metal complexes [M(L1)2] and [M(L2)2], where M = Cu(II), Co(II) and Ni(II) were synthesized and characterized by elemental analysis, NMR, IR, UV-visible, mass, magnetic moments, ESR, TGA, SEM, EDX and powder XRD. Based on the experimental data a square planar geometry around the metal ion is assigned to all the complexes (1a-2c). The interaction of synthesized metal complexes with calf thymus DNA was explored using UV-visible absorption spectra, fluorescence and viscosity measurements. The experimental evidence indicated that all the metal complexes strongly bound to CT-DNA through an intercalation mode. DNA cleavage experiments of metal(II) complexes with supercoiled pBR322 DNA have also been explored by gel electrophoresis in the presence of H2O2 as well as UV light, and it is found that the Cu(II) complexes cleaved DNA more effectively compared to Co(II), Ni(II) complexes. In addition, the ligands and their metal complexes were screened for antimicrobial activity and it is found that all the metal complexes were more potent than free ligands.

Synthesis, spectral characterization, molecular modeling, biological activity and potentiometric studies of 4-amino-5-mercapto-3-methyl-S-triazole Schiff's base complexes

NASA Astrophysics Data System (ADS)

Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Alharbi, Suliman A.

2015-03-01

The Schiff's base derived from condensation of s-triazole (4-amino-5-mercapto-3-methyl-S-triazole) with pyridine-2-aldehyde and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR, mass), magnetic moment and thermal measurements. The IR spectral data suggest that the ligand coordinate in a tridentate manner (SNN) via the one thiol (SH), one pyridine ring and the azomethine (Cdbnd N) groups. The data show that the complexes have composition of ML2 type. The activation of thermodynamic parameters are calculated using Coats-Redfern, Horowitz-Metzger (HM), and Piloyan-Novikova (PN). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations and ligand field parameters. Protonation constants of Schiff base and stability constants of their binary metal complexes have been determined potentiometrically in 50% DMSO-water media at 25 °C and ionic strength 0.10 M potassium nitrate. The biological activity of these compounds against various fungi has been investigated.

A novel approach for synthesis of zwitterionic polyurethane coating with protein resistance.

PubMed

Wang, Chunhua; Ma, Chunfeng; Mu, Changdao; Lin, Wei

2014-11-04

We have developed a novel approach to introduce zwitterions into polyurethane for the preparation of antibiofouling coating. First, the thiol-ene click reaction between 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 3-mercapto-1,2-propanediol (TPG) is used to synthesize dihydroxy-terminated DMAEMA (DMA(OH)2) under UV catalysis. The product has been proved by gel permeation chromatography (GPC), Fourier transform infrared spectrum (FT-IR), proton nuclear magnetic resonance ((1)H NMR), and high resolution mass spectrometry (HRMS). DMA(OH)2 is then incorporated into polyurethane as side groups by polyaddition with diisocyanate and further reacts with 1,3-propane sultone to obtain the zwitterionic polyurethanes. The presence of sulfobetaine zwitterions side groups has been demonstrated by FT-IR and X-ray photoelectron spectroscopy (XPS). Thermal analysis indicates that the thermal stability is decreased with the increasing content of zwitterionions. The antibiofouling property of polyurethanes has been investigated by the measurement of adsorption of fibrinogen, bovine serum albumin (BSA), and lysozyme on the polyurethanes surface using quartz crystal microbalance with dissipation (QCM-D). The results show that the polyurethane coatings exhibit effective nonspecific protein resistance at higher content of zwitterionic side groups.

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates.

PubMed

Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

2015-04-05

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates

NASA Astrophysics Data System (ADS)

Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

2015-04-01

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

Synthesis, crystal structures and spectroscopic properties of triazine-based hydrazone derivatives; a comparative experimental-theoretical study.

PubMed

Arshad, Muhammad Nadeem; Bibi, Aisha; Mahmood, Tariq; Asiri, Abdullah M; Ayub, Khurshid

2015-04-03

We report here a comparative theoretical and experimental study of four triazine-based hydrazone derivatives. The hydrazones are synthesized by a three step process from commercially available benzil and thiosemicarbazide. The structures of all compounds were determined by using the UV-Vis., FT-IR, NMR (1H and 13C) spectroscopic techniques and finally confirmed unequivocally by single crystal X-ray diffraction analysis. Experimental geometric parameters and spectroscopic properties of the triazine based hydrazones are compared with those obtained from density functional theory (DFT) studies. The model developed here comprises of geometry optimization at B3LYP/6-31G (d, p) level of DFT. Optimized geometric parameters of all four compounds showed excellent correlations with the results obtained from X-ray diffraction studies. The vibrational spectra show nice correlations with the experimental IR spectra. Moreover, the simulated absorption spectra also agree well with experimental results (within 10-20 nm). The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the compounds indicated their chemical reactivates. Furthermore, frontier molecular orbital (electronic properties) and first hyperpolarizability (nonlinear optical response) were also computed at the B3LYP/6-31G (d, p) level of theory.

Synthesis, structural and fungicidal studies of hydrazone based coordination compounds

NASA Astrophysics Data System (ADS)

Sharma, Amit Kumar; Chandra, Sulekh

2013-02-01

The coordination compounds of the Co(II), Ni(II) and Cu(II) metal ions derived from imine based ligand, benzil bis(carbohydarzone) were structurally and pharmaceutically studied. The compounds have the general stoichiometry [M(L)]X2 and [Co(L)X2], where M = Ni(II) and Cu(II), and X=NO3- and Cl- ions. The analytical techniques like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV/Visible, NMR, ESI mass and EPR were used to study the compounds. The key IR bands, i.e., amide I, amide II and amide III stretching vibrations accounts for the tetradentate metal binding nature of the ligand. The electronic and EPR spectral results suggest the square planar Ni(II) and Cu(II) complexes (giso = 2.11-2.22) and tetragonal geometry Co(II) complexes (giso = 2.10-2.17). To explore the compounds in the biological field, they were examined against the opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The partial covalent character of metal-ligand bond is supported by the orbital reduction factor k (0.62-0.92) and nephalauxetic parameter β (0.55-0.57).

Spectroscopic and density functional theory studies of 5,7,3',5'-tetrahydroxyflavanone from the leaves of Olea ferruginea.

PubMed

Hashmi, Muhammad Ali; Khan, Afsar; Ayub, Khurshid; Farooq, Umar

2014-07-15

5,7,3',5'-Tetrahydroxyflavanone (1) was isolated from the leaves of Olea ferruginea and a theoretical model was developed for obtaining the electronic and spectroscopic properties of 1. The geometric and electronic properties were calculated at B3LYP/6-311 G (d, p) level of Density Functional Theory (DFT). The theoretical data was in good agreement with the experimental one. The optimized geometric parameters of compound 1 were calculated for the first time. The theoretical vibrational frequencies of 1 were found to correlate with the experimental IR spectrum after a scaling factor of 0.9811. The UV and NMR spectral data computed theoretically were in good agreement with the experimental data. Electronic properties of the compound i.e., ionization potential (IP), electron affinity (EA), coefficients of HOMO and LUMO were estimated computationally for the first time which can be used to explain its antioxidant as well as other related activities and more active sites on it. The intermolecular interactions and their effects on IR frequencies, electronic and geometric parameters were simulated using water molecule as a model for hydrogen bonding with flavonoid hydroxyl groups. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectroscopic and density functional theory studies of 5,7,3‧,5‧-tetrahydroxyflavanone from the leaves of Olea ferruginea

NASA Astrophysics Data System (ADS)

Hashmi, Muhammad Ali; Khan, Afsar; Ayub, Khurshid; Farooq, Umar

2014-07-01

5,7,3‧,5‧-Tetrahydroxyflavanone (1) was isolated from the leaves of Olea ferruginea and a theoretical model was developed for obtaining the electronic and spectroscopic properties of 1. The geometric and electronic properties were calculated at B3LYP/6-311 G (d, p) level of Density Functional Theory (DFT). The theoretical data was in good agreement with the experimental one. The optimized geometric parameters of compound 1 were calculated for the first time. The theoretical vibrational frequencies of 1 were found to correlate with the experimental IR spectrum after a scaling factor of 0.9811. The UV and NMR spectral data computed theoretically were in good agreement with the experimental data. Electronic properties of the compound i.e., ionization potential (IP), electron affinity (EA), coefficients of HOMO and LUMO were estimated computationally for the first time which can be used to explain its antioxidant as well as other related activities and more active sites on it. The intermolecular interactions and their effects on IR frequencies, electronic and geometric parameters were simulated using water molecule as a model for hydrogen bonding with flavonoid hydroxyl groups.

Experimental and theoretical studies of structural and photophysical properties of a novel heteroleptic cyclometalated iridium(III) complex with 8-hydroxyquinoline-phenylazo ligand

NASA Astrophysics Data System (ADS)

Maity, Amit; Sinha, Debopam; Rajak, Kajal Krishna

2018-04-01

One novel heteroleptic iridium(III) complex with cyclometalated 2-phenylquinoline(2-phq) was synthesized by the stoichiometric reaction of [Ir(2-phq)2Cl]2, i.e, Bis-[μ-chlorodi-(2-phenylquinoline)iridium(III)] and HL ligand, where L- is deprotonated form of azo ligand prepared from 8-hydroxyquinoline and aniline in a 1:1 proportion of dichloromethane and ethanol solvent at argon atmosphere in presence of mild base triethylamine in stoichiometric ratio. The prepared complex was characterized by 1H NMR, ESI-mass spectrometry, IR spectroscopy and most accurately by X-ray single crystallography. The photo physical properties like absorption and emission, i.e, photoluminescence in liquid state as well as solid state were studied exclusively. The experimental electrochemical study was also done with cyclic voltammetry. The theoretical investigations of the photo physical properties were done by DFT and TDDFT calculations. The ground state excitation transitions of the complex arise from 1ILCT and 1MLCT transition. The UV-Vis and photoluminescence transition was also investigated by NTO analysis. The triplet state emission transition was characterized by 3MLCT and some portion of 3ILCT transition.

Spectral characterization and antibacterial activity of an isolated compound from Memecylon edule leaves.

PubMed

Srinivasan, R; Natarajan, D; Shivakumar, M S

2017-03-01

Memecylon edule Roxb. (Melastamataceae family) is a small evergreen tree reported as having ethnobotanical and pharmacological properties. The present study was aimed to investigate the spectral characterization and antibacterial activity of isolated pure compound (3β-hydroxyurs-12-en-28-oic acid (ursolic acid)) from Memecylon edule leaves by performing bioassay guided isolation method. The structure derivation of isolated compound was done by different spectral studies like UV, FT-IR, LC-MS, CHNS analysis, 1D ( 1 H, 13 C and DEPT-135) and 2D-NMR (HSQC and HMBC), respectively. About 99.29% purity of the compound was found in LC analysis. 1 H NMR spectrum results of compound shown 48 protons appear at different shielded region and most of the protons were present in aliphatic region. Whereas, 13 C NMR spectral data resulted seven methyl carbons (CH3), nine methylene carbons (CH2), seven methine carbons (CH) and six non-hydrogenated carbons (C) which are characteristic of pentacyclic triterpene. The isolated pure compound was tested for its antibacterial properties against targeted human pathogens by performing agar well diffusion, MIC and MBC assays and the result exhibits better growth inhibitory effects against S. epidermidis and S. pneumoniae, with the MIC values of 1.56 and 3.15μg/ml. The outcome of this study suggests that the bioactive compound is used for development of plant based drugs in pharmaceutical industry for combating microbial mediated diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, structural, DFT studies, docking and antibacterial activity of a xanthene based hydrazone ligand

NASA Astrophysics Data System (ADS)

Naseem, Saira; Khalid, Muhammad; Tahir, Muhammad Nawaz; Halim, Mohammad A.; Braga, Ataualpa A. C.; Naseer, Muhammad Moazzam; Shafiq, Zahid

2017-09-01

Herein, we present the synthesis of novel xanthene-based hydrazone (1). The chemical structure of 1 was resolved using spectroscopic techniques such as NMR, FT-IR, UV-VIS and X-ray crystallographic approaches. X-ray diffraction analysis shows that the compound (1) crystallizes in triclinic crystal lattice with the Pbar1 space group and diffused to form multi-layered structure due to non-covalent interactions such as intramolecular hydrogen bonding (H.B). In addition to experimental investigation, density functional theory (DFT) calculation with M06-2X/6-31G(d,p) and B3LYP/6-31G(d,p) level of theories was performed on compound (1) to obtain optimized geometry, spectroscopic and electronic properties. DFT optimized geometry shows good agreement with the experimental XRD structure. The hyper conjugative interactions and hydrogen bonding network are responsible for the stability of compound (1) as revealed by natural bond orbital (NBO) calculation. Moreover, hydrogen bonding network in the dimer is confirmed by FT-IR and thermodynamic studies showing excellent agreement with XRD and NBO findings. TD-DFT/UV-VIS analysis provides insight that maximum excitation is found in 1 which shows good agreement with experimental UV-VIS result. The global reactivity parameters are calculated using the energies of frontier molecular orbitals also disclosed that the compound is more stable might be due to hydrogen bonding network. Experimental and molecular docking studies indicated that this compound has anti-bacterial and anti-diabetic properties. The binding affinity of this compound against the multidrug efflux pump subunit AcrB OS=Escherichia coli (strain K12) and Human Pancreatic Alpha-Amylase is -9.2 and -10.00 kcal/mol which are higher than the control drugs. Pi-Pi, Pi-anaion, amide-pi and pi-alkyl bonds play key role in drug-protein complexes.

Novel aldehyde and thiosemicarbazone derivatives: Synthesis, spectroscopic characterization, structural studies and molecular docking studies

NASA Astrophysics Data System (ADS)

Karakurt, Tuncay; Tahtaci, Hakan; Subasi, Nuriye Tuna; Er, Mustafa; Ağar, Erbil

2016-12-01

In this study our purpose is that, synthesis and characterization of compounds containing the aldehyde and thiosemicarbazone groups and comparison of the theoretical results with the experimental results. The structures of all synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, elemental analyses techniques. The structure of compound (4) (C9H8N4O2S) was also elucidated by X-ray diffraction analysis. In addition, the theoretical IR spectrum, 1H NMR and 13C NMR chemical shift values, frontier molecular orbital values (FMO) of these molecules were analyzed by using Becke-3- Lee-Yang-Parr (B3LYP) method with LanL2DZ basis set. Finally, molecular docking studies were performed on synthesized compounds using the 4DKI beta-lactam protein structure to determine the potential binding mode of inhibitors.

Properties of infrared extrapolations in a harmonic oscillator basis

DOE PAGES

Coon, Sidney A.; Kruse, Michael K. G.

2016-02-22

Here, the success and utility of effective field theory (EFT) in explaining the structure and reactions of few-nucleon systems has prompted the initiation of EFT-inspired extrapolations to larger model spaces in ab initio methods such as the no-core shell model (NCSM). In this contribution, we review and continue our studies of infrared (ir) and ultraviolet (uv) regulators of NCSM calculations in which the input is phenomenological NN and NNN interactions fitted to data. We extend our previous findings that an extrapolation in the ir cutoff with the uv cutoff above the intrinsic uv scale of the interaction is quite successful,more » not only for the eigenstates of the Hamiltonian but also for expectation values of operators, such as r 2, considered long range. The latter results are obtained with Hamiltonians transformed by the similarity renormalization group (SRG) evolution. On the other hand, a possible extrapolation of ground state energies in the uv cutoff when the ir cutoff is below the intrinsic ir scale is not robust and does not agree with the ir extrapolation of the same data or with independent calculations using other methods.« less

Synthesis and characterization of triazole based supramolecule for interaction with cefuroxime in tap water and blood plasma.

PubMed

Ahmed, Farid; Perveen, Samina; Shah, Kiramat; Shah, Muhammad Raza; Ahmed, Shakil

2018-01-01

In this study a new calix[4]arene triazole 5 was successfully synthesized using click reaction and characterized through UV-visible, FT-IR, 1 H NMR spectroscopes and Mass Spectrometry. The supramolecular interaction of compound 5 towards commonly used drugs has been carried out using UV-Visible spectroscopy. The supramolecule 5 showed characteristic enhancement in the absorbance intensity after mixing with Cefuroxime at pH (2-12). Compound 5 displayed considerably good interactions with cefuroxime in the presence of other drugs. Compound 5 exhibits linear relationship with cefuroxime concentration in the range of (10-80µM) with regression value of 0.9954. The standard deviation for 50µM Cefuroxime was found to be 0.01 and the limit of detection for cefuroxime was calculated to be 2µM. Job's plot experiments showed 1:1 (5: cefuroxime) binding stoichiometry between compound 5 and cefuroxime. Supramolecule 5 displayed fairly good spectrophotometric recognition of Cefuroxime in human blood plasma and tap water thus showing that the ingredients of tap water and plasma sample was inert in the recognition of cefuroxime. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis, spectra and X-ray crystallography of dipyridin-2-ylmethanone oxime and its CuX2(oxime)2 complexes: Thermal, Hirshfeld surface and DFT analysis

NASA Astrophysics Data System (ADS)

Warad, Ismail; Abdoh, Muneer; Al Ali, Anas; Shivalingegowda, Naveen; Kumara, Karthik; Zarrouk, Abdelkader; Lokanath, Neartur Krishnappagowda

2018-02-01

Dipyridin-2-ylmethanone oxime (C11H9N3O), was prepared using di-2-pyridyl ketone. The oxime ligand and its neutral CuX2 (oxime)2 (X = Cl or Br) complexes have been identified with the aid of several spectroscopic techniques such as: IR, EI-MS, EA, UV-visible, TG, 1H-NMR and finally the structure of the free oxime ligand was confirmed by X-ray diffraction studies. The oxime crystallizes in the monoclinic space group P21/c, with cell parameters a = 8.8811 (8) Å, b = 10.6362 (8) Å, c = 11.2050 (8) Å, β = 109.085 (4) º, V = 1000.26 (14) Å3 and Z = 4. The molecular conformation is stabilized by a strong intramolecular Osbnd H⋯N hydrogen bonding between the hydroxyl group of the oxime moiety and the nitrogen of the pyridine ring. Since the oxime structure was solved by XRD, the ligand structure parameters like bond length and angles were compared to the DFT computed one, the UV-visible to TD-SCF and Hirshfeld surface to MEP analysis.

Investigation on the inclusion interaction of 4-sulfonatocalix[n]arenes with 1-(4-nitrophenyl)piperazine

NASA Astrophysics Data System (ADS)

Zhang, Yongbin; Chao, Jianbin; Zhao, Shuhui; Xu, Penghao; Wang, Hongfang; Guo, Zhiqiang; Liu, Diansheng

2014-11-01

The inclusion behaviors of 4-Sulfonatocalix[n]arenes (SCXn) (n = 4, 6, 8) with 1-(4-nitrophenyl)piperazine (NPP) were investigated by UV spectroscopy and fluorescence spectroscopy at different pH values (pH = 3.05, 6.50, 8.40). The UV absorption and fluorescence intensity of NPP remarkably increased in presence of SCXn revealing formation of the inclusion complexes between NPP and SCXn. Moreover, the formation constants (K) of inclusion complexes were also determined by the non-linear fitting method, and the obtained data showed that the formation constants decreased gradually with the increasing of the pH value. When the pH value was 3.05, the formation constant of NPP with SCX8 reached a maximum of 1.7 × 107 L mol-1. The stoichiometric ratio was verified to be 1:1 by the continuous variation method. Meanwhile FT-IR and DSC analysis also indicated that NPP could form the inclusion complex with SCXn. In order to explore the inclusion mechanism of NPP with SCXn, 1H NMR and molecular modeling studies were carried out and experimental results showed that the part of benzene ring of NPP penetrated into the hydrophobic cavity of SCXn.

New phthalimide-appended Schiff bases: Studies of DNA binding, molecular docking and antioxidant activities.

PubMed

Nayab, Pattan Sirajuddin; Akrema; Ansari, Istikhar A; Shahid, Mohammad; Rahisuddin

2017-08-01

Herein, we investigated new phthalimide-based Schiff base molecules as promising DNA-binding and free radical scavenging agents. Physicochemical properties of these molecules were demonstrated on the basis of elemental analysis, ultraviolet-visible (UV-Vis), infra-red (IR), 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. All spectral data are agreed well with the proposed Schiff base framework. The DNA-binding potential of synthesized compounds were investigated by means of UV-visible, fluorescence, iodide quenching, circular dichroism, viscosity and thermal denaturation studies. The intrinsic binding constants (K b ) were calculated from absorption studies were found to be 1.1 × 10 4 and 1.0 × 10 4  M -1 for compounds 2a and 2b suggesting that compound 2a binding abilities with DNA were stronger than the compound 2b. Our studies showed that the presented compounds interact with DNA through groove binding. Molecular docking studies were carried out to predict the binding between Ct-DNA and test compounds. Interestingly, in silico predictions were corroborated with in vitro DNA-binding conclusions. Furthermore, the title compounds displayed remarkable antioxidant activity compared with reference standard. Copyright © 2016 John Wiley & Sons, Ltd.

Anti-proliferative effect of fungal taxol extracted from Cladosporium oxysporum against human pathogenic bacteria and human colon cancer cell line HCT 15

NASA Astrophysics Data System (ADS)

Gokul Raj, K.; Manikandan, R.; Arulvasu, C.; Pandi, M.

2015-03-01

Cladosporium oxysporum a new taxol producing endophytic fungus was identified and production of taxol were characterized using UV-visible spectroscopy (UV-vis), high-performance liquid chromatography (HPLC), infrared (IR) nuclear magnetic resonance spectroscopy (NMR (13C and 1H)) and liquid chromatography-mass spectrometry (LC-MS). The taxol biosynthetic gene (dbat) was evaluated for new taxol producing fungus. Antibacterial activity against six different human pathogenic bacteria was done by agar well diffusion method. The anticancer efficacy of isolated fungal taxol were also evaluated in human colon cancer cell HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cytotoxicity and nuclear morphology analysis. The isolated fungal taxol showed positive towards biosynthetic gene (dbat) and effective against both Gram positive as well as Gram negative. The fungal taxol suppress growth of cancer cell line HCT 15 with an IC50 value of 3.5 μM concentration by 24 h treatment. Thus, the result reveals that C. oxysporum could be a potential alternative source for production of taxol and have antibacterial as well as anticancer properties with possible clinical applications.

Shedding light on the photostability of two intermolecular charge-transfer complexes between highly fluorescent bis-1,8-naphthalimide dyes and some π-acceptors: A spectroscopic study in solution and solid states

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; Ismail, Lamia A.; Adam, Abdel Majid A.

2015-01-01

Given the great importance of the various uses of 1,8-naphthalimides in the trends of biology, medicine and industry, the current study focused on extending the scope of these dyes by introducing some of their charge-transfer (CT) complexes. For this purpose, two highly fluorescent bis-1,8-naphthalimide dyes and their complexes with some π-acceptors have been synthesized and characterized spectroscopically. The π-acceptors include picric acid (PA), chloranilic acid (CLA), tetracyanoquinodimethane (TCNQ) and dichlorodicyanobenzoquinone (DDQ). The molecular structure, spectroscopic and fluorescence properties as well as the binding modes were deduced from IR, UV-vis and 1H NMR spectral studies. The binding ratio of complexation was determined to be 1:1 according to the elemental analyses and photometric titrations. It has been found that the order of acceptance ability for the different acceptors is TCNQ > DDQ > CLA > PA. The photostability of 1,8-naphthalimide dye as a donor and its charge-transfer complex doped in polymethyl methacrylate/PMMA were exposed to UV-Vis radiation and the change in the absorption spectra was achieved at different times during irradiation period.

Molecular structure, supramolecular association and anion sensing by chlorodiorganotin(IV) methylferrocenyldithiocarbamates

NASA Astrophysics Data System (ADS)

Yadav, Reena; Awasthi, Mahendra Kumar; Singh, Amita; Kociok-Köhn, Gabriele; Trivedi, Manoj; Prasad, Rajendra; Shahid, Mohammad; Kumar, Abhinav

2017-10-01

Three new chlorodiorganotin(IV) methylferrocenyl dithiocarbamate complexes viz. [(FcCH2)(CH2CH2OH)NCS2SnMe2(Cl)] (1), [(FcCH2)(CH2CH2OH)NCS2SnnBu2(Cl)] (2) and [(FcCH2)(CH2CH2OH)NCS2SnPh2(Cl)] (3) have been synthesized and characterized by elemental analysis, IR, UV-Vis, 1H, 13C and 119Sn NMR spectroscopy and X-ray crystallography. The crystal structure of 1 indicates that the coordination geometries around the tin(IV) center is intermediate between ideal trigonal-bipyramidal and square pyramidal coordination polyhedra bonded through two sulfur atoms of the dithiocarbamate ligand in an isobidentate mode, two CH3 groups and one chlorine atom. Since, in 2 and 3 only alkyl and aryl fragments have been changed we infer that both 2 and 3 would also have the same behaviors in the solution state as observed in 1. Ionic interactions abilities of 1-3 are examined in acetonitrile through UV-vis absorption spectroscopy which offers reasonably good selectivity and sensitivity towards the detection of the acetate ion. Compounds 1-3 exhibit a bathochromic shift with the acetate ion with a moderate association constant.

IR and NMR studies of hierarchical material obtained by the treatment of zeolite Y by ammonia solution

NASA Astrophysics Data System (ADS)

Gackowski, Mariusz; Kuterasiński, Łukasz; Podobiński, Jerzy; Sulikowski, Bogdan; Datka, Jerzy

2018-03-01

Ammonia treatment of ultrastable zeolite Y has a great impact on its features. XRD showed a partial loss of crystallinity coupled with a loss of long-distance zeolite ordering. However, a typical short-range zeolite ordering, in the light of 29Si NMR studies, was largely preserved. 27Al MAS NMR spectra evidenced that most of Al was located in zeolitic tetrahedral positions, but some of them adopted a distorted configuration. Evolution of zeolites acidity was followed quantitatively by using IR. In particular, such studies revealed the presence of strongly acidic Sisbnd OHsbnd Al groups. IR studies suggest also heterogeneity of these OH groups. The heterogeneity of Sisbnd OHsbnd Al groups was a consequence of the less ordered structure of zeolites treated with ammonia solutions. It was also found that the treatment with ammonia solutions yields hierarchical material. The samples revealed promising catalytic properties in the liquid phase isomerization of α-pinene. Zeolites desilicated with ammonia may constitute an inexpensive route yielding viable hierarchical catalysts.

FT-IR, FT-Raman, NMR studies and ab initio-HF, DFT-B3LYP vibrational analysis of 4-chloro-2-fluoroaniline

NASA Astrophysics Data System (ADS)

Arivazhagan, M.; Anitha Rexalin, D.

2012-10-01

The Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 4-chloro-2-fluoroaniline (CFA) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated with the help of ab initio and density functional theory (DFT) methods. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the Gauge including atomic orbital (GIAO) method. The first order hyperpolarizability (β0) of this novel molecular system and related properties (β, α0 and Δα) of CFA are calculated using B3LYP/6-311++G(d,p) and HF/6-311++G(d,p) methods on the finite-field approach. The calculated results also show that the CFA molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The result confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. The HOMO-LUMO energies UV-vis spectral analysis and MEP are performed by B3LYP/6-311++G(d,p) approach. A detailed interpretation of the infrared and Raman spectra of CFA is also reported based on total energy distribution (TED). The difference between the observed and scaled wave number values of the most of the fundamentals is very small.

Crystal structures, Hirshfeld surface analysis, thermal behavior and dielectric properties of a new organic-inorganic hybrid [C6H10(NH3)2]Cu2Cl8

NASA Astrophysics Data System (ADS)

Salah, Najet; Hamdi, Besma; Bouzidia, Nabaa; Salah, Abdelhamid Ben

2017-12-01

A novel organic-inorganic hybrid sample [C6H10(NH3)2]Cu2Cl8 has been prepared under mild hydrothermal conditions and characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, FT-IR,NMR and UV-Vis spectroscopies, differential scanning calorimetric and dielectric measurement. It is crystallized in the monoclinic system with P21/c space group. The cohesion and stabilization of the structure are provided by the hydrogen bond interactions, (Nsbnd H⋯Cl and Csbnd H⋯Cl), between [C6H10(NH3)2]2+ cation and [Cu2Cl8]2- anion. The Hirschfeld surface analysis has been performed to explore the behavior of these weak interactions. The presence of different functional groups and the nature of their vibrations were identified by FT-IR and Solid state NMR. The thermal study revealed that this compound undergoes two structural phase transitions around 353 and 376 K. Electrical measurements of our compounds have been investigated using complex impedance spectroscopy (CIS) in the frequency and temperature range 331-399 K and 200 Hz-5 MHz, respectively. The AC conductivity is explained using the correlated barrier hopping model (CBH) conduction mechanism. The nature of DC conductivity variation suggests Arrhenius type of electrical conductivity. A relationship between crystal structure and ionic conductivity was established and discussed. Finally, the real and imaginary parts of the permittivity constant are analyzed with the Cole-Cole formalism and the optical spectra indicate that the compound has a direct band gap (3.14 eV) due to direct transition. The wide band gap is due to low defect concentration in the grown crystal, which is more useful for the laser/optical applications.

DFT calculations on molecular structure, spectral analysis, multiple interactions, reactivity, NLO property and molecular docking study of flavanol-2,4-dinitrophenylhydrazone

NASA Astrophysics Data System (ADS)

Singh, Ravindra Kumar; Singh, Ashok Kumar

2017-02-01

A new flavanol-2,4-dinitrophenylhydrazone (FDNP) was synthesized and its structure was confirmed by FT-IR, FT-Raman, 1H NMR, mass spectrometry and elemental analysis. All quantum chemical calculations were carried out at level of density functional theory (DFT) with B3LYP functional using 6-311++ G (d,p) basis atomic set. UV-Vis absorption spectra for the singlet-singlet transition computed for fully optimized ground state geometry using Time-Dependent-Density Functional Theory (TD-DFT) with CAM-B3LYP functional was found to be in consistent with that of experimental findings. Analysis of vibrational (FT-IR and FT-Raman) spectrum and their assignments has been done by computing Potential Energy Distribution (PED) using Gar2ped. HOMO-LUMO analysis was performed and reactivity descriptors were calculated. Calculated global electrophilicity index (ω = 7.986 eV) shows molecule to be a strong electrophile. 1H NMR chemical shift calculated with the help of gauge-including atomic orbital (GIAO) approach shows agreement with experimental data. Various intramolecular interactions were analysed by AIM approach. DFT computed total first static hyperpolarizability (β0 = 189.03 × 10-30 esu) indicates that title molecule can be used as attractive future NLO material. Solvent induced effects on the NLO properties studied by using self-consistent reaction field (SCRF) method shows that β0 value increases with increase in solvent polarity. To study the thermal behaviour of title molecule, thermodynamic properties such as heat capacity, entropy and enthalpy change at various temperatures have been calculated and reported. Molecular docking results suggests title molecule to be a potential kinase inhibitor and might be used in future for designing of new anticancer drug.

FT-IR, FT-Raman, NMR studies and ab initio-HF, DFT-B3LYP vibrational analysis of 4-chloro-2-fluoroaniline.

PubMed

Arivazhagan, M; Anitha Rexalin, D

2012-10-01

The Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 4-chloro-2-fluoroaniline (CFA) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated with the help of ab initio and density functional theory (DFT) methods. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the Gauge including atomic orbital (GIAO) method. The first order hyperpolarizability (β(0)) of this novel molecular system and related properties (β, α(0) and Δα) of CFA are calculated using B3LYP/6-311++G(d,p) and HF/6-311++G(d,p) methods on the finite-field approach. The calculated results also show that the CFA molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The result confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. The HOMO-LUMO energies UV-vis spectral analysis and MEP are performed by B3LYP/6-311++G(d,p) approach. A detailed interpretation of the infrared and Raman spectra of CFA is also reported based on total energy distribution (TED). The difference between the observed and scaled wave number values of the most of the fundamentals is very small. Copyright © 2012 Elsevier B.V. All rights reserved.

Evolution of Functional Groups during Pyrolysis Oil Upgrading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stankovikj, Filip; Tran, Chi-Cong; Kaliaguine, Serge

In this paper, we examine the evolution of functional groups (carbonyl, carboxyl, phenol, and hydroxyl) during stabilization at 100–200 °C of two typical wood derived pyrolysis oils from BTG and Amaron in a batch reactor over Ru/C catalyst for 4h. An aqueous and an oily phase were obtained. The content of functional groups in both phases were analyzed by GC/MS, 31P-NMR, 1H-NMR, elemental analysis, KF titration, carbonyl groups by Faix, Folin – Ciocalteu method and UV-Fluorescence. The consumption of hydrogen was between 0.007 and 0.016 g/g oil, and 0.001-0.020 g of CH4/g of oil, 0.005-0.016 g of CO2/g oil andmore » 0.03-0.10 g H2O/g oil were formed. The content of carbonyl, hydroxyl, and carboxyl groups in the volatile GC-MS detectable fraction decreased (80, 65, and ~70% respectively), while their behavior in the total oil and hence in the non-volatile fraction was more complex. The carbonyl groups initially decreased having minimum at ~125-150°C and then increased, while the hydroxyl groups had reversed trend. This might be explained by initial hydrogenation of the carbonyl groups to form hydroxyls, followed by continued dehydration reactions at higher temperatures that may increase their content. The 31P-NMR was on the limit of its sensitivity for the carboxylic groups to precisely detect changes in the non-volatile fraction, however the more precise titration method showed that the concentration of carboxylic groups in the non-volatile fraction remains constant with increased stabilization temperature. The UV-Fluorescence results show that repolymerization increases with temperature. ATR-FTIR method coupled with deconvolution of the region between 1490 and 1850 cm-1 showed to be a good tool for following the changes in carbonyl groups and phenols of the stabilized pyrolysis oils. The deconvolution of the IR bands around 1050 and 1260 cm-1 correlated very well with the changes in the 31P-NMR silent O groups (likely ethers). Most of the H2O formation could be explained from the significant reduction of these silent O groups (from 12% in the fresh oils, to 6 to 2% in the stabilized oils) most probably belonging to ethers.« less

Electronic structure investigations of 4-aminophthal hydrazide by UV-visible, NMR spectral studies and HOMO-LUMO analysis by ab initio and DFT calculations.

PubMed

Sambathkumar, K; Jeyavijayan, S; Arivazhagan, M

2015-08-05

Combined experimental and theoretical studies were conducted on the molecular structure and vibrational spectra of 4-AminoPhthalhydrazide (APH). The FT-IR and FT-Raman spectra of APH were recorded in the solid phase. The molecular geometry and vibrational frequencies of APH in the ground state have been calculated by using the ab initio HF (Hartree-Fock) and density functional methods (B3LYP) invoking 6-311+G(d,p) basis set. The optimized geometric bond lengths and bond angles obtained by HF and B3LYP method show best agreement with the experimental values. Comparison of the observed fundamental vibrational frequencies of APH with calculated results by HF and density functional methods indicates that B3LYP is superior to the scaled Hartree-Fock approach for molecular vibrational problems. The difference between the observed and scaled wave number values of most of the fundamentals is very small. A detailed interpretation of the NMR spectra of APH was also reported. The theoretical spectrograms for infrared and Raman spectra of the title molecule have been constructed. UV-vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by time dependent density functional theory (TD-DFT) approach. Finally the calculations results were applied to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. And the temperature dependence of the thermodynamic properties of constant pressure (Cp), entropy (S) and enthalpy change (ΔH0→T) for APH were also determined. Copyright © 2015 Elsevier B.V. All rights reserved.

Spectroscopic and chemical reactivity analysis of D-Myo-Inositol using quantum chemical approach and its experimental verification

NASA Astrophysics Data System (ADS)

Mishra, Devendra P.; Srivastava, Anchal; Shukla, R. K.

2017-07-01

This paper describes the spectroscopic (^1H and ^{13}C NMR, FT-IR and UV-Visible), chemical, nonlinear optical and thermodynamic properties of D-Myo-Inositol using quantum chemical technique and its experimental verification. The structural parameters of the compound are determined from the optimized geometry by B3LYP method with 6 {-}311{+}{+}G(d,p) basis set. It was found that the optimized parameters thus obtained are almost in agreement with the experimental ones. A detailed interpretation of the infrared spectra of D-Myo-Inositol is also reported in the present work. After optimization, the proton and carbon NMR chemical shifts of the studied compound are calculated using GIAO and 6 {-}311{+}{+}G(d,p) basis set. The search of organic materials with improved charge transfer properties requires precise quantum chemical calculations of space-charge density distribution, state and transition dipole moments and HOMO-LUMO states. The nature of the transitions in the observed UV-Visible spectrum of the compound has been studied by the time-dependent density functional theory (TD-DFT). The global reactivity descriptors like chemical potential, electronegativity, hardness, softness and electrophilicity index, have been calculated using DFT. The thermodynamic calculation related to the title compound was also performed at B3LYP/ 6 {-}311{+}{+}G(d,p) level of theory. The standard statistical thermodynamic functions like heat capacity at constant pressure, entropy and enthalpy change were obtained from the theoretical harmonic frequencies of the optimized molecule. It is observed that the values of heat capacity, entropy and enthalpy increase with increase in temperature from 100 to 1000 K, which is attributed to the enhancement of molecular vibration with the increase in temperature.

Structure-property relationship of 3-(4-substituted benzyl)-1,3-diazaspiro[4.4]nonane-2,4-diones as new potentional anticonvulsant agents. An experimental and theoretical study

NASA Astrophysics Data System (ADS)

Lazić, Anita M.; Božić, Bojan Đ.; Vitnik, Vesna D.; Vitnik, Željko J.; Rogan, Jelena R.; Radovanović, Lidija D.; Valentić, Nataša V.; Ušćumlić, Gordana S.

2017-01-01

The structure-property relationship of newly synthesized 3-(4-substituted benzyl)-1,3-diazaspiro [4.4]nonane-2,4-diones was studied by experimental and calculated methods. The prepared compounds were characterized by UV-Vis, FT-IR, 1H NMR and 13C NMR spectroscopy and elemental analysis. The crystal structure was elucidated by single-crystal X-ray diffraction. The 3-benzyl-1,3-diazaspiro[4.4]nonane-2,4-dione crystallizes in triclinic P-1 space group, with two crystallographically independent molecules in the asymmetric unit. Cyclopentane ring adopts an envelope conformation. A three-dimensional crystal packing is governed by hydrogen N-H⋯O bonds, numerous C-H⋯O/N and C-H … π interactions between neighboring molecules. Density functional theory (DFT) calculations with B3LYP and M06-2X methods using 6-311++G(d,p) basis set were performed to provide structural and spectroscopic information. Comparisons between experimental and calculated UV-Vis spectral properties suggest that the monomeric form of the investigated spirohydantoins is dominant in all used solvents. The effects of substituents on the absorption spectra of spirohydantoins are interpreted by correlation of absorption frequencies with Hammett equation. The lipophilicities of the investigated molecules were estimated by calculation of their log P values. Some of the spirohydantoins synthesized in this work, exhibit the lipophilicities comparable to the standard medicine anticonvulsant drug Phenytoin. The results obtained in this investigation afford guidelines for the preparation of new derivatives of spirohydantoin as potential anticonvulsant agents and for better understanding the structure-activity relationship.

Synthesis, structure and study of azo-hydrazone tautomeric equilibrium of 1,3-dimethyl-5-(arylazo)-6-amino-uracil derivatives.

PubMed

Debnath, Diptanu; Roy, Subhadip; Li, Bing-Han; Lin, Chia-Her; Misra, Tarun Kumar

2015-04-05

Azo dyes, 1,3-dimethyl-5-(arylazo)-6-aminouracil (aryl=-C6H5 (1), -p-CH3C6H4 (2), -p-ClC6H4 (3), -p-NO2C6H4 (4)) were prepared and characterized by UV-vis, FT-IR, 1H NMR, 13C NMR spectroscopic techniques and single crystal X-ray crystallographic analysis. In the light of spectroscopic analysis it evidences that of the tautomeric forms, the azo-enamine-keto (A) form is the predominant form in the solid state whereas in different solvents it is the hydrazone-imine-keto (B) form. The study also reveals that the hydrazone-imine-keto (B) form exists in an equilibrium mixture with its anionic form in various organic solvents. The solvatochromic and photophysical properties of the dyes in various solvents with different hydrogen bonding parameter were investigated. The dyes exhibit positive solvatochromic property on moving from polar protic to polar aprotic solvents. They are fluorescent active molecules and exhibit high intense fluorescent peak in some solvents like DMSO and DMF. It has been demonstrated that the anionic form of the hydrazone-imine form is responsible for the high intense fluorescent peak. In addition, the acid-base equilibrium in between neutral and anionic form of hydrazone-imine form in buffer solution of varying pH was investigated and evaluated the pKa values of the dyes by making the use of UV-vis spectroscopic methods. The determined acid dissociation constant (pKa) values increase according to the sequence of 2>1>3>4. Copyright © 2014 Elsevier B.V. All rights reserved.

White organic light-emitting diodes utilized by near UV-deep blue emitter and exciplex emission.

PubMed

Park, Young Wook; Kim, Young Min; Choi, Jin Hwan; Park, Tae Hyun; Choi, Hyun Ju; Yu, Hong Jung; Cho, Min Ju; Choi, Dong Hoon; Kim, Sung Hyun; Ju, Byeong Kwon

2011-02-01

Numerous investigations have been made into the development of wide color gamut displays for deep-blue OLEDs, including the RGB sub pixels, and white OLEDs (WOLEDs). One of the well known deep-blue emissive dopants, tris(phenyl-methyl-benzimidazolyl)iridium(III) [Ir(pmb)3], successfully introduced its fascinating color coordinate of Commission Internationale de l'Eclairage (CIE) 1931 (0.17, 0.06), however there have been no reports utilizing its accomplishments as WOLEDs. In this report, using only one phosphorescent dopant, the near UV-deep blue emissive Ir(pmb)3, the WOLEDs having the CIE 1931 coordinate of (0.33, 0.38) at 100 cd/m2 with a color rendering index of 85 are demonstrated. The white emission of the fabricated OLEDs are oriented from the near UV-deep blue emission of Ir(pmb)3 and the successfully controlled exciplex emission, between the Ir(pmb)3-host, and the Ir(pmb)3-interfaced material.

Novel dimeric metabolites from Alternaria tagetica.

PubMed

Gamboa-Angulo, M M; Alejos-González, F; Escalante-Erosa, F; García-Sosa, K; Delgado-Lamas, G; Peña-Rodríguez, L M

2000-08-01

Two novel polyketides, bis-7-O-8' '.8-O-7' '- and bis-7-O-7' '. 8-O-8' '-zinniol (2 and 3, respectively) were isolated from the organic crude extract of culture filtrates from Alternaria tagetica. Both structures were determined on the basis of their spectroscopic data (IR, MS, (1)H NMR, (13)C NMR, and 2D NMR experiments) and confirmed by chemical synthesis. Zinniol (1) was isolated as a major component, and its (13)C NMR data was correctly assigned after careful analysis of data from its 2D NMR experiments (HMQC and HMBC).

Suicide Inhibitors of Reverse Transcriptase in the Therapy of AIDS and Other Retroviruses

DTIC Science & Technology

1991-07-01

procedures and characterized by IR and NMR spectroscopy . 140 OH py’ridine Ho t O0Tr OHr01 9 10 1 croi 0 0 Aco uO (CH43)2 -CN TOOH pyridja. 0 OxTr D?450...NMR spectroscopy . The observed chemical shifts are comparable to those reported ’in the literature. The spectrum is of the ABX type where the AB part...characterized by NMR spectroscopy . The presence of the characteristic triphosphate group was confirmed by NMR as indicated in the figure below. NMR

Synthesis, spectroscopic characterization and a comparative study of the corrosion inhibitive efficiency of an α-aminophosphonate and Schiff base derivatives: Experimental and theoretical investigations

NASA Astrophysics Data System (ADS)

Benbouguerra, Khalissa; Chafaa, Salah; Chafai, Nadjib; Mehri, Mouna; Moumeni, Ouahiba; Hellal, Abdelkader

2018-04-01

New α-aminophosphonate (α-APD) and Schiff base (E-NDPIMA) derivatives have been prepared and their structures ware proved by IR, UV-Vis, 1H, 13C and 31P NMR spectroscopy. Their inhibitive capacities on the XC48 carbon steel corrosion in 0.5 mol L-1 H2SO4 solution were explored by weight loss, Tafel polarization, electrochemical impedance spectroscopy (EIS) and atomic force microscope (AFM). Experimental results illustrate that the synthesized compounds are an effectives inhibitors and the adsorption of inhibitors molecules on the carbon steel surface obeys Langmuir adsorption isotherm. In addition, quantum chemical calculations performed with density function theory (DFT) method have been used to correlate the inhibition efficiency established experimentally. Also, the molecular dynamics simulations have been utilized to simulate the interactions between the inhibitors molecules and Fe (100) surface in aqueous solution.

Zn2+ -Ion Sensing by Fluorescent Schiff Base Calix[4]arene Macrocycles.

PubMed

Ullmann, Steve; Schnorr, René; Handke, Marcel; Laube, Christian; Abel, Bernd; Matysik, Jörg; Findeisen, Matthias; Rüger, Robert; Heine, Thomas; Kersting, Berthold

2017-03-17

A macrocyclic ligand (H 2 L) containing two o,o'-bis(iminomethyl)phenol and two calix[4]arene head units has been synthesized and its coordination chemistry towards divalent Ni and Zn investigated. The new macrocycle forms complexes of composition [ML] (M=Zn, M=Ni) and [ZnL(py) 2 ], which were characterized by elemental analysis; IR, UV/Vis, and NMR spectroscopy; electrospray ionization mass spectrometry (ESI-MS); and X-ray crystallography (for [ZnL(py) 2 ] and [NiL]). H 2 L allows the sensitive optical detection of Zn 2+ among a series of biologically relevant metal ions by a dual fluorescence enhancement/quenching effect in solution. The fluorescence intensity of the macrocycle increases by a factor of ten in the presence of Zn 2+ with a detection limit in the lower nanomolar region. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Spectral Evaluation of Some Unsymmetrical Mesoporphyrinic Complexes

PubMed Central

Boscencu, Rica; Oliveira, Anabela Sousa; Ferreira, Diana P.; Ferreira, Luís Filipe Vieira

2012-01-01

Synthesis and spectral evaluation of new zinc and copper unsymmetrical mesoporphyrinic complexes are reported. Zn(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Zn(II)-5-[(3,4-methylenedioxy)phenyl]-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Cu(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin and Cu(II)-5-[(3,4-methylenedioxy)phenyl]-10,15,20- tris-(4-carboxymethylphenyl)porphyrin were synthesized using microwave-assisted synthesis. The complexes were characterized by elemental analysis, FT-IR, UV-Vis, EPR and NMR spectroscopy, which fully confirmed their structure. The spectral absorption properties of the porphyrinic complexes were studied in solvents with different polarities. Fluorescence emission and singlet oxygen formation quantum yields were evaluated for the compounds under study, revealing high yields for the zinc derivatives. The copper complexes are not emissive and only display residual capacity for singlet oxygen formation. PMID:22942693

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation.

PubMed

Ercan, Utku K; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D; Joshi, Suresh G

2016-02-02

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation.

Quantum chemical characterization of N-(2-hydroxybenzylidene)acetohydrazide (HBAH): a detailed vibrational and NLO analysis.

PubMed

Tamer, Ömer; Avcı, Davut; Atalay, Yusuf

2014-01-03

The molecular modeling of N-(2-hydroxybenzylidene)acetohydrazide (HBAH) was carried out using B3LYP, CAMB3LYP and PBE1PBE levels of density functional theory (DFT). The molecular structure of HBAH was solved by means of IR, NMR and UV-vis spectroscopies. In order to find the stable conformers, conformational analysis was performed based on B3LYP level. A detailed vibrational analysis was made on the basis of potential energy distribution (PED). HOMO and LUMO energies were calculated, and the obtained energies displayed that charge transfer occurs in HBAH. NLO analysis indicated that HBAH can be used as an effective NLO material. NBO analysis also proved that charge transfer, conjugative interactions and intramolecular hydrogen bonding interactions occur through HBAH. Additionally, major contributions from molecular orbitals to the electronic transitions were investigated theoretically. Copyright © 2013 Elsevier B.V. All rights reserved.

Basic Principles of Spectroscopy

NASA Astrophysics Data System (ADS)

Penner, Michael H.

Spectroscopy deals with the production, measurement, and interpretation of spectra arising from the interaction of electromagnetic radiation with matter. There are many different spectroscopic methods available for solving a wide range of analytical problems. The methods differ with respect to the species to be analyzed (such as molecular or atomic spectroscopy), the type of radiation-matter interaction to be monitored (such as absorption, emission, or diffraction), and the region of the electromagnetic spectrum used in the analysis. Spectroscopic methods are very informative and widely used for both quantitative and qualitative analyses. Spectroscopic methods based on the absorption or emission of radiation in the ultraviolet (UV), visible (Vis), infrared (IR), and radio (nuclear magnetic resonance, NMR) frequency ranges are most commonly encountered in traditional food analysis laboratories. Each of these methods is distinct in that it monitors different types of molecular or atomic transitions. The basis of these transitions is explained in the following sections.

An unexpected Schiff base-type Ni(II) complex: Synthesis, crystal structures, fluorescence, electrochemical property and SOD-like activities

NASA Astrophysics Data System (ADS)

Chai, Lan-Qin; Zhang, Hong-Song; Huang, Jiao-Jiao; Zhang, Yu-Li

2015-02-01

An unexpected Schiff base-type Ni(II) complex, [Ni(L2)2]ṡCH3OH (HL2 = 1-(2-{[(E)-3, 5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Ni(II) acetate tetrahydrate with HL1 (2-(3,5-dibromo-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide) originally. HL1 and its corresponding Ni(II) complex were characterized by IR, 1H NMR spectra, as well as by elemental analysis, UV-Vis and emission spectroscopy, respectively. Crystal structures of the ligand and complex have been determined by single-crystal X-ray diffraction. Each complex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonding interactions. Moreover, the electrochemical property of the nickle complex was studied by cyclic voltammetry. In addition, SOD-like activities of HL1 and Ni(II) complex were also investigated.

Crystal structures and catalytic performance of three new methoxy substituted salen type nickel(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

NASA Astrophysics Data System (ADS)

Ghaffari, Abolfazl; Behzad, Mahdi; Pooyan, Mahsa; Amiri Rudbari, Hadi; Bruno, Giuseppe

2014-04-01

Three new nickel(II) complexes of a series of methoxy substituted salen type Schiff base ligands were synthesized and characterized by IR, UV-Vis and 1H NMR spectroscopy and elemental analysis. The ligands were synthesized from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine with n-methoxysalicylaldehyde (n = 3, 4 and 5). Crystal structures of these complexes were determined. Electrochemical behavior of the complexes was studied by means of cyclic voltammetry in DMSO solutions. Catalytic performance of the complexes was studied in the epoxidation of cyclooctene using tert-butylhydroperoxide (TBHP) as oxidant under various conditions to find the optimum operating parameters. Low catalytic activity with moderate epoxide selectivity was observed in in-solvent conditions but in the solvent-free conditions, enhanced catalytic activity with high epoxide selectivity was achieved.

[Effect of gene disruption of aveD on avermectins production in Streptomyces avermitilis].

PubMed

Chen, Z; Song, Y; Wen, Y; Li, J

2001-08-01

Recombinant plasmid pCZ2(pKC1139::475 bp aveD) was used for aveD gene disruption in Streptomyces avermitilis 76-9. The plasmid was inserted into the chromosome by homogenous recombination between partial aveD gene in the plasmid and aveD in the chromosome. Disruptants were confirmed by Southern blotting. Shaking flask experiments and HPLC analysis showed that the disruptant produced only four components, which were C5-oxo-avermectin B1a, B1b, B2a, B2b as identified by UV, IR, NMR, and MS. This revealed that both aveD and aveF were not expressed in the disruptant. This is consistent with that aveD and aveF are in a transcription unit. This paper also provided a new genetic method to obtain C5-oxo-avermectin B-producing strain.

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation

PubMed Central

Ercan, Utku K.; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D.; Joshi, Suresh G.

2016-01-01

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation. PMID:26832829

Zunyimycins B and C, New Chloroanthrabenzoxocinones Antibiotics against Methicillin-Resistant Staphylococcus aureus and Enterococci from Streptomyces sp. FJS31-2.

PubMed

Lü, Yuhong; Shao, Meiyun; Wang, Yinyin; Qian, Shengyan; Wang, Miao; Wang, Yingquan; Li, Xiaoqian; Bao, Yuxin; Deng, Chengmin; Yue, Changwu; Liu, Daishun; Liu, Ning; Liu, Minghao; Huang, Ying; Chen, Zehui; Hu, Yonglin

2017-02-08

This study performed an optimization of the fermentation conditions to activate the expression of the zunyimycin family biosynthesis genes of the zunyimycin-producing streptomycetes strain Streptomyces sp. FJS31-2. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of the zunyimycin derivatives, namely, 31-2-7 and 31-2-8, accompanied with three known anthrabenzoxocinones family members of zunyimycin A, BE24566B, and chloroanthrabenzoxocinone. Their structures were elucidated by NMR, HRESIMS, IR, UV, and CD. Results showed that these two compounds were structurally similar to the previously reported compound zunyimycin A but differed in positions and number of chlorine atom substitution. The two novel compounds were called zunyimycins B and C. Antibacterial activity assay indicated that zunyimycin C showed a good inhibitory effect on the methicillin-resistant Staphylococcus aureus and Enterococci .

Rapid detection of HSO4- in water: Novel immobilized azo-azomethine colorimetric anion receptors on solid supports

NASA Astrophysics Data System (ADS)

Hezaveh, Saba Mahdavi; Khanmohammadi, Hamid; Zendehdel, Mojgan

2018-06-01

The immobilized azo-azomethine receptors on amorphous SiO2, S-B, SiO2 nanoparticles, S-NPs, and NaY zeolite, S-ZY, have been prepared and applied as solid phase sensors for detection of HSO4-, over other interfering anions, in 100% aqueous media. Remarkably, S-B and S-ZY show unique and rapid sensitivity towards HSO4-, which could it easily visualized through naked eye detection even at 5 × 10-4 mol L-1 and 4 × 10-4 mol L-1, respectively. The fabricated solid phase sensors were characterized using powder XRD diffraction, TGA-DTA, FE-SEM and also FT-IR techniques. Moreover, the related molecular anion receptor, HL, has been prepared and used for naked eye detection of F- and AcO-, in dry DMSO. The anions recognition ability of HL was also evaluated using UV-Vis and 1H NMR spectroscopic methods.

Damxungmacin A and B, Two New Amicoumacins with Rare Heterocyclic Cores Isolated from Bacillus subtilis XZ-7.

PubMed

Tang, Hui-Ling; Sun, Cheng-Hang; Hu, Xin-Xin; You, Xue-Fu; Wang, Min; Liu, Shao-Wei

2016-11-23

Two new amicoumacins, named Damxungmacin A ( 1 ) and B ( 2 ), were isolated from the culture broth of a soil-derived bacterium Bacillus subtilis XZ-7. Their chemical structures were elucidated by spectroscopic studies (UV, IR, NMR and HR-ESI-MS). Compound 1 possessed a 1,4-diazabicyclo[2.2.1]heptane-2-one ring system in its structure, which was reported for the first time, while 2 had a 1-acetylmorpholine-3-one moiety, which was naturally rare. Compound 1 exhibited moderate to weak cytotoxic activities against three human tumor cell lines (A549, HCT116 and HepG2) with IC 50 values of 13.33, 14.34 and 13.64 μM, respectively. Meanwhile, compound 1 showed weak antibacterial activities against some strains of Staphylococcus epidermidis , while compound 2 at 16 μg/mL did not show antibacterial activity.

Preparation, characterization, and in vitro anti-inflammatory evaluation of novel water soluble kamebakaurin/hydroxypropyl-β-cyclodextrin inclusion complex

NASA Astrophysics Data System (ADS)

Raza, Aun; Sun, Huifang; Bano, Shumaila; Zhao, Yingying; Xu, Xiuquan; Tang, Jian

2017-02-01

To enhance the aqueous solubility of kamebakaurin (KA), it was complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD). In this study, the interaction KA with HP-β-CD and their inclusion complex behavior were determined by different characterization techniques such as UV-vis, 1H NMR, FT-IR, PXRD and SEM. All the characterization information proved the development of inclusion complex KA/HP-β-CD, and this inclusion complex demonstrated discriminable spectroscopic characteristics and properties from free compound KA. The results demonstrated that the water solubility of KA was remarkably increased in the presence of HP-β-CD. Furthermore, in vitro anti-inflammatory study showed that inclusion complex KA/HP-β-CD maintained the anti-inflammatory effect of KA. These results demonstrate that HP-β-CD will be promisingly employed in the application of water-insoluble anti-inflammatory phytochemicals such as KA.

Ultrafast third-order nonlinear optical response of pyrene derivatives

NASA Astrophysics Data System (ADS)

Shi, Yufang; Li, Zhongguo; Fang, Yu; Sun, Jinyu; Zhao, Minggen; Song, Yinglin

2017-05-01

Two mono-substituted pyrene derivatives with delocalized electron system 1-(pyren-1-yl)-3-(4-Methyl thiophene-2-yl) acrylic ketone (13#) and 1-(pyren-1-yl)-3-(4-bromo thiophene-2-yl) acrylic ketone (15#) were successfully synthesized. The resultant compounds were characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (IR), high resolution mass spectrum (HR-MS), and UV-vis spectra. The third-order nonlinear optical properties of the compounds were investigated using Z-scan technique with femtosecond laser pulses at 500 nm and 700 nm, respectively. Both of the compounds showed a decrease in transmittance about the focus, which are typical of two-photon absorption. It was found that the two-photon absorption behavior of the pyrene derivatives were modified by substituents on thiophene ring. These results indicate that both compounds can be promising candidates for future optoelectronic and bio-imaging applications.

Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

PubMed Central

Ncube, Phendukani; Krause, Rui W.; Mamba, Bhekie B.

2011-01-01

A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs) of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2,4-dichlorophenol, with a sensitivity factor of 0.35 compared to 0.05 and 0.12 for phenol and 4-chlorophenol, respectively. The stability constants (Ks) of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 103 M−1 for 2,4-dichlorophenol and 1.120 × 102 M−1 for 4-chlorophenol. PMID:22163864

Chemical modification of botryosphaeran: structural characterization and anticoagulant activity of a water-soluble sulfonated (1-->3)(1-->6)-β-D-glucan.

PubMed

Brandi, Jamile; Oliveira, Éder C; Monteiro, Nilson; Vasconcelos, Ana Flora D; Dekker, Robert F H; Barbosa, Aneli M; Silveira, Joana L M; Mourão, Paulo A S; Corradi da Silva, Maria de Lourdes

2011-10-01

The exopolysaccharide botryosphaeran (EPS(GLC); a (1--> 3)(1-->6)-β-D-glucan from Botryosphaeria rhodina MAMB- 05) was sulfonated to produce a water-soluble fraction (EPS(GLC)-S) using pyridine and chlorosulfonic acid in formamid. This procedure was then repeated twice to produce another fraction (EPSGLC-RS) with a higher degree of substitution (DS, 1.64). The purity of each botryosphaeran sample (unsulfonated and sulfonated) was assessed by gel filtration chromatography (Sepharose CL-4B), where each polysaccharide was eluted as a single symmetrical peak. The structures of the sulfonated and re-sulfonated botryosphaerans were investigated using ultraviolet-visible (UV-Vis), Fourier-transform infrared (FT-IR), and (13)C nuclear magnetic resonance ((13)C NMR) spectroscopies. EPS(GLC) and EPS(GLC)-RS were also assayed for anticoagulation activity, and EPS(GLC)-RS was identified as an anticoagulant.

Metabolomics study of Populus type propolis.

PubMed

Anđelković, Boban; Vujisić, Ljubodrag; Vučković, Ivan; Tešević, Vele; Vajs, Vlatka; Gođevac, Dejan

2017-02-20

Herein, we propose rapid and simple spectroscopic methods to determine the chemical composition of propolis derived from various Populus species using a metabolomics approach. In order to correlate variability in Populus type propolis composition with the altitude of its collection, NMR, IR, and UV spectroscopy followed by OPLS was conducted. The botanical origin of propolis was established by comparing propolis spectral data to those of buds of various Populus species. An O2PLS method was utilized to integrate two blocks of data. According to OPLS and O2PLS, the major compounds in propolis samples, collected from temperate continental climate above 500m, were phenolic glycerides originating from P. tremula buds. Flavonoids were predominant in propolis samples collected below 400m, originating from P. nigra and P. x euramericana buds. Samples collected at 400-500m were of mixed origin, with variable amounts of all detected metabolites. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel oxime based flavanone, naringin-oxime: synthesis, characterization and screening for antioxidant activity.

PubMed

Ozyürek, Mustafa; Akpınar, Damla; Bener, Mustafa; Türkkan, Baki; Güçlü, Kubilay; Apak, Reşat

2014-04-05

Recent interest in polyphenolic antioxidants due to their involvement in health benefits has led to the investigation of new polyphenolic compounds with enhanced antioxidant activity. Naringin (4',5,7-trihydroxyflavanone-7-β-l-rhamnoglucoside-(1,2)-α-d-glucopyranoside) is one of the major flavanones in citrus and grapefruit. The present study aimed to synthesize naringin oxime from naringin and to evaluate its antioxidant and anticancer potential using in vitro assay system. The structure of the synthesized compound, naringin oxime, was elucidated by FT-IR, (1)H NMR, elemental analysis and UV-vis spectroscopy. Antioxidant capacity of naringin oxime, as measured by the cupric reducing antioxidant capacity (CUPRAC) method, was found to be higher than that of the parent compound naringin. Other parameters of antioxidant activity (scavenging effects on OH, O2(-), and H2O2) of naringin and naringin oxime were also determined. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Synthesis, structure and antidiabetic activity of chromium(III) complexes of metformin Schiff-bases

NASA Astrophysics Data System (ADS)

Mahmoud, M. A.; Zaitone, S. A.; Ammar, A. M.; Sallam, S. A.

2016-03-01

A series of Cr3+ complexes with Schiff-bases of metformin with each of salicylaldehyde (HL1); 2,3-dihydroxybenzaldehyde (H2L2); 2,4-dihydroxybenzaldehyde (H2L3); 2,5-dihydroxybenzaldehyde (H2L4); 3,4-dihydroxybenzaldehyde (H2L5) and 2-hydroxynaphthaldehyde (HL6) were synthesized by template reaction. The new compounds were characterized through elemental analysis, conductivity and magnetic moment measurements, IR, UV-Vis., NMR and mass spectroscopy. The complexes have octahedral structure with μ value of hexacoordinated chromium ion. TGA, DTG and DTA analysis confirm the proposed stereochemistry and a mechanism for thermal decomposition was proposed. Thermodynamic parameters are calculated for the second and third decomposition steps. [CrL4Cl(H2O)2].3H2O and [CrL5Cl(H2O)2].2½H2O were able to produce significant decreases in the blood glucose level.

Highly Efficient and Simple Route to Synthesize N-(4-Acetylphenyl)-4-chlorobenzenesulfonamide and Its Crystal Structure

NASA Astrophysics Data System (ADS)

Kobkeatthawin, T.; Chantrapromma, S.; Chidan Kumar, C. S.; Fun, H.-K.

2017-12-01

The one-pot synthesis of N-(4-acetylphenyl)-4-chlorobenzenesulfonamide under base conditions is carried out. The present method offers several advantages such as excellent yields, short reaction times and high purity. The chemical structure was elucidated using 1H-NMR, FT-IR and UV-Vis spectroscopy. The crystal structure of the substance was determined by single crystal X-ray structure analysis. The molecule is in a V-shape. The two substituted benzene rings make the dihedral angle of 84.31(9)°. In the crystal packing, the molecules are linked by N-H···O and C-H···O hydrogen bonds into double chains along the b-axis. The crystal is further stabilized by weak C-H···O, C-Cl···π and π···π interactions.

Synthesis and Properties of Poly(l-lactide)-b-poly (l-phenylalanine) Hybrid Copolymers

PubMed Central

Planellas, Marc; Puiggalí, Jordi

2014-01-01

Hybrid materials constituted by peptides and synthetic polymers have nowadays a great interest since they can combine the properties and functions of each constitutive block, being also possible to modify the final characteristics by using different topologies. Poly(l-lactide-b-l-phenylalanine) copolymers with various block lengths were synthesized by sequential ring-opening polymerization of l-lactide and the N-carboxyanhydride of l-phenylalanine. The resulting block copolymers were characterized by NMR spectrometry, IR spectroscopy, gel permeation chromatography, MALDI-TOF and UV-vis, revealing the successful incorporation of the polyphenylalanine (PPhe) peptide into the previously formed poly(l-lactide) (PLLA) polymer chain. X-ray diffraction and DSC data also suggested that the copolymers were phase-separated in domains containing either crystalline PLLA or PPhe phases. A peculiar thermal behavior was also found by thermogravimetric analysis when polyphenylalanine blocks were incorporated into polylactide. PMID:25075980

Synthesis and properties of poly(L-lactide)-b-poly (L-phenylalanine) hybrid copolymers.

PubMed

Planellas, Marc; Puiggalí, Jordi

2014-07-29

Hybrid materials constituted by peptides and synthetic polymers have nowadays a great interest since they can combine the properties and functions of each constitutive block, being also possible to modify the final characteristics by using different topologies. Poly(l-lactide-b-l-phenylalanine) copolymers with various block lengths were synthesized by sequential ring-opening polymerization of l-lactide and the N-carboxyanhydride of l-phenylalanine. The resulting block copolymers were characterized by NMR spectrometry, IR spectroscopy, gel permeation chromatography, MALDI-TOF and UV-vis, revealing the successful incorporation of the polyphenylalanine (PPhe) peptide into the previously formed poly(l-lactide) (PLLA) polymer chain. X-ray diffraction and DSC data also suggested that the copolymers were phase-separated in domains containing either crystalline PLLA or PPhe phases. A peculiar thermal behavior was also found by thermogravimetric analysis when polyphenylalanine blocks were incorporated into polylactide.