FT-Raman, FT-IR spectral and DFT studies on (E)-1-4-nitrobenzylidenethiocarbonohydrazide

Quantum mechanical calculation of optimized parameters, vibrational wavenumbers and energies of (E)-1-4-nitrobenzylidenethiocarbonohydrazide ((E)-1-4-NBTCH) was carried out using Hatree Fock (HF) with 6-31G(d,p), 6-311G(d,p) basis sets and density functional theory (DFT) with 6-31G(d,p) basis set. The optimized geometrical parameters obtained by HF and DFT are in better agreement with analogues single XRD data. The vibrational wavenumbers were calculated and the complete assignments were performed on the basis of total energy distribution (TED), calculated with scaled quantum mechanical (SQM) method. The electrical dipole moment (μ) and first hyperpolarizability (β0) values have been computed using ab initio and DFT quantum mechanical calculation. The calculated results (β0) show that the title molecule might have nonlinear optical (NLO) behaviour. The total energy, dipole moment and rotational constant are reported for the title molecule. The HOMO–LUMO energies were calculated and natural bonding orbital (NBO) analysis has also been carried out.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Molecular geometry. ► Vibrational assignments using TED. ► First order hyperpolarizability (β0). ► Natural bond orbital analysis (NBO). ► HOMO–LUMO band gap energy.