Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV–Visible), first order hyperpolarizability, NBO and molecular docking study of (E)-1-(4-bromobenzylidene)semicarbazide

The compound (E)-1-(4-bromobenzylidene)semicarbazide(4BSC) was synthesized and characterized by FT-IR, FT-Raman, UV–Visible, 1HNMR and 13CNMR spectra. The optimized molecular geometry(bond length, bond angle), the complete vibrational frequency, the infrared intensities and the Raman scattering activities 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–Visible spectrum, the electronic properties such as excitation energies, wavelength, band gap and oscillator strength are evaluated by TD-DFT in DMSO solution and gas phase methods using 6-311++G(d,p) basis set. The calculated HOMO - LUMO band gap energies confirm that charge transfer occurs within the molecule. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge-independent atomic orbital (GIAO) method and compared with experimental results. The hyperconjugative interaction energy E(2) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. Besides NLO and MEP were also calculated and interpreted. To study the biological activity of the investigation molecule, molecular docking was done to identify the hydrogen bond lengths and binding energy with different antimicrobial protein. Thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations the heat capacity (C), entropy (S) and enthalpy changes (H) and temperatures.