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The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 2-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole 3-oxide have been investigated experimentally and theoretically. Gauge-including atomic orbital 1 H NMR chemical shifts calculations were carried out and compared with experimental data. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated geometrical parameters are in agreement with that of similar derivatives. Molecular electrostatic potential was performed by the DFT method. Mulliken’s net charges have been calculated and compared with the atomic natural charges. First and second hyperpolarizability are calculated in order to find its role in non-linear optics. Molecular docking is also reported. [ABSTRACT FROM AUTHOR]

FT-IR and FT-Raman spectra of ethyl 3-( E )-(anthracen-9-yl)prop-2-enoate were recorded and analyzed. The conformational behavior of the molecule was also investigated. The vibrational wavenumbers were calculated using DFT quantum chemical calculations. The data obtained from the wavenumber calculations were used to assign vibrational bands obtained experimentally. The geometrical parameters are in agreement with XRD data. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis were used to determine the charge transfer within the molecule and quantum chemical parameters related to the title compound. From the MEP analysis, it is clear that the negative electrostatic potential regions are mainly localized over the carbonyl groups and anthracene ring and are possible sites for electrophilic attack and the positive regions are localized at all the hydrogen atoms as possible sites for nucleophilic attack. NLO and NMR studies are also reported. Molecular docking studies suggest that the title compound might exhibit inhibitory activity against IDE and may act as an insulysin inhibitor. Conformational analysis is also reported. [ABSTRACT FROM AUTHOR]

The Fourier-Transform Infrared and Fourier-Transform Raman spectra of 2,2-diphenyl-4-(piperidin-1-yl)butanamide were recorded in the region 4000–400 cm −1 and 4000–0 cm −1 . The vibrational wavenumbers are computed using HF and DFT methods. The complete vibrational assignments were performed on the basis of potential energy distribution using GAR2PED program. The geometrical parameters of the title compound are in agreement with the XRD data. From the MEP study, the negative electrostatic potential regions are mainly localized of carbonyl group and are possible sites for electrophilic attack and the positive regions are localized all the rings, indicating possible sites for nucleophilic attack. Stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using natural bond orbital analysis. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. PASS analysis of the title compound predicts among other activities, antidyskinetic activity. Molecular docking results draw us to the conclusion that the compound might exhibit inhibitory activity against adenosine A2A and may act as antidyskinetic agent. [ABSTRACT FROM AUTHOR]

In this work, the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy of 2-(4-hydroxyphenyl)-4,5-dimethyl-1H-imidazole 3-oxide. The computations were performed at DFT levels of theory to get the optimized geometry and vibrational frequencies of the normal modes of the title compound using Gaussian09 software. The complete vibrational assignments of frequencies were made on the basis of potential energy distribution. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The hyperpolarizability values are reported and the first hyperpolarizability of the title compound is 19.61 times that of standard NLO material urea. From the MEP plot, the negative charge covers the nitro group and the positive region is over the hydroxyl group and N–H part of the imidazole ring. The calculated 1 H NMR results are in good agreement with experimental data. Molecular docking study is also reported. [ABSTRACT FROM AUTHOR]

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 5-tert-Butyl-6-chloro- N -[(4-(trifluoromethyl)phenyl]pyrazine-2-carboxamide have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. From the NBO analysis it is evident that the increased electron density at the nitrogen, carbon atoms leads to the elongation of respective bond length and a lowering of the corresponding stretching wave number. The calculated geometrical parameters are in agreement with that of similar derivatives. The calculated first hyperpolarizability is high and the calculated data suggest an extended π-electron delocalization over the pyrazine ring and carboxamide moiety which is responsible for the nonlinearity of the molecule. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR, Raman spectra and NBO analysis of 5-nitro-2-phenylbenzoxazole were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The optimized geometrical parameters of 5-nitro-2-phenylbenzoxazole are in agreement with that of similar compounds. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR and Raman spectra were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that of similar derivatives. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR, Raman and NBO were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that of similar derivatives. [Copyright &y& Elsevier]

Highlights: [•] IR, Raman spectra and NBO analysis were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] NBO, HOMO–LUMO analysis shows ICT, π delocalization in the molecule. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR, Raman spectra and NBO analysis were reported. [•] The wave numbers are calculated theoretically using Gaussian09 software. [•] The wave numbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that of similar derivatives. [ABSTRACT FROM AUTHOR]

Abstract: The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 5-nitro-2-(4-nitrobenzyl) benzoxazole have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program. The energy and oscillator strength calculated by time dependent density functional theory almost compliments with experimental findings. Gauge-including atomic orbital 1H NMR chemical shifts calculations were carried out by using B3LYP functional with 6-31G* basis set. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization have been analyzed using NBO analysis. MEP was performed by the DFT method and the predicted infrared intensities and Raman activities have also been reported. The calculated geometrical parameters are in agreement with that of similar derivatives. [Copyright &y& Elsevier]

Abstract: FT-IR and FT-Raman spectra of (E)-N-Carbamimidoyl-4-((naphthalen-1-yl-methylene)amino)benzene sulfonamide were recorded and analyzed. The vibrational wavenumbers were computing at various levels of theory. The data obtained from theoretical calculations are used to assign vibrational bands obtained experimentally. The results indicate that B3LYP method is able to provide satisfactory results for predicting vibrational frequencies and structural parameters. The calculated first hyperpolarizability is comparable with reported values of similar derivatives and is an attractive object for future studies of non-linear optics. The geometrical parameters of the title compound are in agreement with that of similar derivatives. [Copyright &y& Elsevier]

Abstract: Fourier-transform (FT)-Raman and FT-infrared spectrum of 4-(3-bromopropyl)-4-azatricyclo [5.2.2.02,6]undecane-3,5,8-trione were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution (PED) calculations. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with reported values of similar structures which makes this compound an attractive object for future studies of nonlinear optics. The calculated first hyperpolarizability was found to be very high and it is due to the π-electron cloud movement from donor to acceptor which makes the molecule highly polarized and the intermolecular charge transfer interaction which is justified by the FT-IR spectrum due to the presence of strong broad bands in the region 2873–2000cm−1. Optimized geometrical parameters of the compound are in agreement with similar reported structures. [Copyright &y& Elsevier]

Abstract: FT-IR and FT-Raman spectra of 4-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl acetate were recorded and analyzed. Synthesis and elemental analysis are also reported. The vibrational wavenumbers of the compound have been computed on the basis of density functional theory using B3LYP/6-31G* basis set. The predicted infrared intensities and Raman activities are reported. [Copyright &y& Elsevier]

Abstract: FT-Raman and FT-IR spectra of 2-cyanophenylisocyanid dichloride were recorded and analyzed. The vibrational frequencies of the title compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values. The prepared compound was identified by NMR and mass spectra. [Copyright &y& Elsevier]

Abstract: FT-Raman and FT-IR spectra of sulfanilamide were recorded and analyzed. The vibrational frequencies of the compound have been computed using the Hartree–Fock/6-21G* basis and compared with the experimental values. The assignments of the observed bands were made on the basis of available literature. [Copyright &y& Elsevier]

Abstract: FT-IR and FT-Raman spectra of pyridine-3-sulfonic acid are recorded and analysed. Surface enhanced Raman scattering (SERS) spectrum is recorded in a silver colloid. The bands due to υCH, υSO are enhanced in the SERS spectrum. A likely ‘perpendicular orientation’ of the molecule on the silver surface is suggested. [Copyright &y& Elsevier]

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of N -[(4-(trifluoromethyl)phenyl]pyrazine-2-carboxamide have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. From the NBO analysis it is evident that the increased electron density at the nitrogen and carbon atoms leads to the elongation of their respective bond lengths and a lowering of their corresponding stretching wavenumbers. The calculated geometrical parameters are in agreement with that of similar derivatives. The calculated first hyperpolarizability is high and the calculated data suggest an extended π -electron delocalization over the pyrazine ring and carboxamide moiety which is responsible for the nonlinearity of the molecule. [ABSTRACT FROM AUTHOR]

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 2-[( E )-2-(2-bromophenyl)ethenyl]quinoline-6-carboxylic acid have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program. 1 H NMR chemical shifts calculations were carried out by using B3LYP functional with SDD basis set. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. MEP was performed by the DFT method and the predicted infrared intensities and Raman activities have also been reported. The calculated geometrical parameters are in agreement with that of similar derivatives. The title compound forms a stable complex with PknB as is evident from the binding affinity values and the molecular docking results suggest that the compound might exhibit inhibitory activity against PknB and this may result in development of new anti-tuberculostic agents. [ABSTRACT FROM AUTHOR]

FT-IR and FT-Raman spectra of (2 E )- N -(4-chloro-2-oxo-1,2-dihydroquinolin-3-yl)-3-phenylprop-2-enamide were recorded and analyzed experimentally and theoretically. The synthesis, 1 H NMR and PES scan results are also discussed. Nonlinear optical behavior of the examined molecule was investigated by the determination of first hyperpolarizability. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. From the MEP it is evident that the negative charge covers the carbonyl group and the positive region is over the NH group. The calculated geometrical parameters (SDD) are in agreement with that of similar derivatives. Molecular docking simulations against targets from Mycobacterium tuberculosis are reported and the results suggest that the compound might exhibit inhibitory activity against PknB. [ABSTRACT FROM AUTHOR]

FT-IR and FT-Raman spectra of 2-[( E )-2-phenylethenyl]quinoline-5-carboxylic acid were recorded and obtained and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The geometrical parameters (SDD) of the title compound are in agreement with that of similar derivatives. Stability of the molecule arising from the hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital analysis. From the natural and Mulliken charges, it can be concluded that electrophilic substitution of the quinoline scaffold is more preferred than nucleophilic substitution. From the MEP map it is evident that the negative regions are mainly localized over the carbonyl group and are possible sites for electrophilic attack. The title compound forms a stable complex with PknB as is evident from the binding affinity values and the molecular docking study suggests that the compound might exhibit inhibitory activity against PknB. [ABSTRACT FROM AUTHOR]

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of the title compound have been investigated experimentally and theoretically. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analysed using NBO analysis. The hyperpolarisability calculation reveals the present material has a reasonably good propensity for nonlinear optical activity. Due to the different potential biological activity of the title compound, molecular docking study is also reported and the compound might exhibit inhibitory activity against human M 2 muscarinic acetylcholine receptor. [ABSTRACT FROM AUTHOR]

FT-IR and FT-Raman spectra of 4-Methylphenylquinoline-2-carboxylate were recorded and analyzed. The structure of the molecule has been optimized and structural characteristics have been determined by density functional theory. The geometrical parameters (DFT) are in agreement with the XRD results. HOMO and LUMO and other chemical properties are reported. Nonlinear optical properties are also reported. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. The negative (red and yellow) regions of the MEP are related to electrophilic reactivity and the positive (blue) regions to nucleophilic reactivity, as shown in the MEP plot and the carbonyl group and the phenyl rings are observed as electrophilic. PASS analysis predicts that the 4-Methylphenylquinoline-2-carboxylate might exhibit anti-diabetic activity. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR, Raman spectra and acid–base properties are reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The geometrical parameters are in agreement with the XRD data. [•] Application of FMO, MEP and PED analyses of PyPi. [Copyright &y& Elsevier]

Highlights: [•] IR, Raman, NBO analysis and MEP were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with the reported literature. [Copyright &y& Elsevier]

Highlights: [•] IR, Raman, NBO analysis and MEP were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with the reported literature. [Copyright &y& Elsevier]

Abstract: Infrared and Raman spectroscopic analyses were carried out on 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione. The interpretation of the spectra was aided by DFT calculation of the molecule. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes and the normal modes were assigned by potential energy distribution calculations. A computation of the first hyperpolarizability of the compound indicates that the compound may be a good candidate as a NLO material. Optimized geometrical parameters are in agreement with the reported XRD results. The RMS error of the observed Raman bands and IR bands are found to be 35.09 and 39.57 for HF method and 14.31 and 17.17 for DFT method. The predicted infrared intensities and Raman activities are reported. [Copyright &y& Elsevier]

Abstract: The FT-IR and FT-Raman spectra of 5-chloro-2-(3-chlorophenylcarbamoyl)phenylacetate were studied. The vibrational wave numbers and corresponding vibrational assignments were examined theoretically using the Gaussian 03 set of quantum chemistry codes and the normal modes are assigned by Potential Energy Distribution calculations. The synthesis, elemental analysis and NMR values are presented. The red shift of the NH stretching wave number in the infrared spectrum from the computed wave number indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of nonlinear optics. The geometrical parameters of the title compound are in agreement with that of similar reported derivatives. [Copyright &y& Elsevier]

Abstract: The infrared and Raman spectra of (E)-4-((anthracen-9-ylmethylene)amino)-N-carbamimidoylbenzene sulfonamide have been recorded and analysed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian03 set of quantum chemistry codes. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in infrared and Raman spectra of the studied molecule. The red-shift of the NH stretching band in the infrared spectrum from the computed wavenumber indicates the weakening of the NH bond. The NH stretching band has split into a doublet in the IR spectrum owing to the Davydov coupling between neighbouring units. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The calculated first hyperpolarizability is comparable with the reported value of similar structures and may be an attractive object for further studies on non-linear optics. The important thermodynamical parameters are also reported. [Copyright &y& Elsevier]

Abstract: Fourier-transform infrared (FT-IR) and FT-Raman spectra of 4-fluoro-N-(2′-hydroxy-4′-nitrophenyl)phenylacetamide were recorded and analyzed. A surface-enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using quantum mechanical calculations. The red shift of the NH stretching wavenumber in the IR spectrum from the calculated wavenumber indicates the weakening of NH bond resulting in proton transfer to the neighboring oxygen atom. The presence of CH2 and NO2 modes in the SERS spectrum indicates the nearness of these groups to the metal surface, which affects the orientation and metal molecule interaction. The presence of phenyl ring deformation bands, show a tilted orientation of the molecule with respect to the silver surface. The first hyperpolarizability and predicted infrared intensities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar structures and is an attractive object for further studies of nonlinear optics. [Copyright &y& Elsevier]

Abstract: The infrared and Raman spectra of N-carbamimidoyl-4-((2-hydroxybenzylidene) amino) benzenesulfonamide have been recorded and analyzed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian 03 set of quantum chemistry codes. Calculations were performed at the DFT (B3LYP) and MP2(SDD) levels of theory. The calculated wavenumbers (MP2) agree well with the observed wavenumbers. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in infrared and Raman spectra of the studied molecule. The red-shift of the N–H stretching band in the infrared spectrum from the computed wavenumber indicates the weakening of the N–H bond. The N–H stretching bands has split into a doublet, 3453, 3427 and 3355, 3225cm−1 in the IR spectrum owing to the Davydov coupling between neighboring units. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. Calculated infrared intensities, Raman activities and the first hyperpolarizability are reported. The calculated first hyperpolarizability is comparable with the reported value of similar structures and may be an attractive object for further studies on non linear optics. [Copyright &y& Elsevier]

Abstract: FT-IR and FT-Raman spectra of 1H-2,2-dimethyl-3H-phenothiazin-4[10H]-one were recorded and analyzed. The vibrational wavenumbers were computed using HF/6-31G(d) and B3LYP/6-31G(d) basis. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands obtained in infrared and Raman spectroscopies of the studied molecule. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non-linear optics. The geometrical parameters of the title compound are in agreement with XRD crystal structure data. The red shift of the Ning wavenumber in the infrared spectrum from the computed wavenumber indicates the weakening of the Nce:simple-para> [Copyright &y& Elsevier]

Abstract: FT-Raman and FT-IR spectra of 5-methyl-2-(p-fluorophenyl)benzoxazole were recorded and analysed. The vibrational frequencies of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values. [Copyright &y& Elsevier]

Highlights: [•] IR, Raman spectra and NBO analysis were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that of similar derivatives. [Copyright &y& Elsevier]

Highlights: [•] IR, Raman spectra and NBO analysis were reported. [•] The wavenumbers are calculated theoretically using Gaussian09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that XRD data. [ABSTRACT FROM AUTHOR]

Highlights: [•] IR, Raman and SERS were reported. [•] The wavenumbers are calculated theoretically using Gaussian 09 software. [•] The wavenumbers are assigned using PED analysis. [•] The geometrical parameters are in agreement with that of similar derivatives. [Copyright &y& Elsevier]

Abstract: FT-Raman and FT-IR spectra of ASnFe(PO4)3 [A=Na2, Ca, Cd] were recorded and analyzed. The bands were assigned in terms of the vibrational group frequencies of SnO6 octahedral and PO4 tetrahedral. The spectral analysis shows that the symmetry of corner shared octahedral (SnO6) and the tetrahedral (PO4) are lowered from their free ion symmetry state. The presence of Fe3+ ions disrupts the S–N–O–S–N chain in the structure. This causes distortion of SnO6 and PO4 in the structure of all the compounds. Also it is seen that there are two distinct PO4 tetrahedra of different P–O bond lengths. One of these tetrahedra is linearly distorted in all the title compounds. The PO4 frequencies and bond lengths are calculated theoretically and are in agreement with the experimental values. The presence of PO4 polyanion in the structure can reduce the redox energy and hence reduce the metal oxygen covalency strength in the structure. [ABSTRACT FROM AUTHOR]

Abstract: FT-IR and FT-Raman spectra of ethyl methyl ketone thiosemicarbazone were recorded and analyzed. The crystal structure is also described. The vibrational wavenumbers were computed using HF/6–31G(d) and B3LYP/6–31G(d) basis sets and are assigned with the aid of MOLEKEL program. The first hyperpolarizability, infrared intensities and Raman activities are also reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive molecule for future applications in non-linear optics. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated values. The red shift of the NH stretching wavenumber in the infrared spectrum compared to the computed wavenumber indicates the weakening of the N–H bond resulting in proton transfer to the neighbouring sulfur atom. [Copyright &y& Elsevier]