title: Vibrational spectra, molecular structure, natural bond orbital, first order hyperpolarizability, thermodynamic analysis and normal coordinate analysis of Salicylaldehyde p-methylphenylthiosemicarbazone by density functional method.
abstract: The thiosemicarbazone compound, Salicylaldehyde p-methylphenylthiosemicarbazone (abbreviated as SMPTSC) was synthesized and characterized by FTIR, FT-Raman and UV. Density functional (DFT) calculations have been carried out for the title compound by performing DFT level of theory using B3LYP/6-31++G(d,p) basis set. The molecular geometry and vibrational frequencies were calculated and compared with the experimental data. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using density functional theory (DFT/B3LYP) with 6-311++G(d,p) basis set. The stability and charge delocalization of the molecule was studied by natural bond orbital (NBO) analysis. Thearomaticities of the phenyl rings were studied using the standard harmonic oscillator model of aromaticity (HOMA) index. Mulliken population analysis on atomic charges is also calculated. The molecule orbital contributions are studied by density of energy states (DOSs).
authors.affiliation: Department of Physics, Anna University, Chennai, Tamil Nadu, India; Department of Physics, Kanchi Pallavan Engineering College, Kanchipuram 631502, Tamil Nadu, India.
authors.forename: E Elamurugu
authors.initials: EE
authors.lastname: Porchelvi
authors.affiliation: Department of Physics, Sri Venkateswara College of Engg, Sriperumbudur 602105, Tamil Nadu, India. Electronic address: muthu@svce.ac.in.
authors.forename: S
authors.initials: S
authors.lastname: Muthu
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D008745:Methylation; D008958:Models, Molecular; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D013882:Thiosemicarbazones / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D013882:Thiosemicarbazones; C013243:salicylaldehyde
keywords: DOSs; FTIR and FT-Raman spectra; HOMA; NCA; UV