Theoretical investigations on molecular structure, vibrational spectra, HOMO, LUMO, NBO analysis and hyperpolarizability calculations of thiophene-2-carbohydrazide

[Display omitted] •FT-IR, FT-Raman spectral investigation of thiophene-2-carbohydrazide performed.•The redistribution of electron density has been discussed.•The HOMO and LUMO energy gap show that charge transfer occurs within the molecule.•The calculated 3D MESP contour map is confirm an electrophi...

Full description

Saved in:
Bibliographic Details
Published in:Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2014-01, Vol.118, p.321-330
Main Authors: Balachandran, V., Janaki, A., Nataraj, A.
Format: Article
Language:English
Subjects:
HOMO
Intramolecular interaction
LUMO analysis
NBO studies
Thiophene-2-carbohydrazide
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •FT-IR, FT-Raman spectral investigation of thiophene-2-carbohydrazide performed.•The redistribution of electron density has been discussed.•The HOMO and LUMO energy gap show that charge transfer occurs within the molecule.•The calculated 3D MESP contour map is confirm an electrophilic and nucleophilic region.•Variation of dipole moment, polarizability is more in TCH1 than TCH2. The Fourier-Transform infrared and Fourier-Transform Raman spectra of thiophene-2-carbohydrazide (TCH) was recorded in the region 4000–400cm−1 and 3500–100cm−1. Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of TCH were carried out by DFT (B3LYP) method with 6-311++G(d,p) as basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. Stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. UV spectrum was measured in different solvent. The energy and oscillator strength are calculated by Time Dependant Density Functional Theory (TD-DFT) results. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The complete assignments were performed on the basis of the potential energy distribution (PED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method. Finally the theoretical FT-IR, FT-Raman, and UV spectra of the title molecule have also been constructed.
ISSN:1386-1425
DOI:10.1016/j.saa.2013.08.091