Quantum Chemical Vibrational Study, Molecular Properties and HOMO-LUMO Energies of 2- Chlorophenylisothiocyanate via Density Functional Theory

Density functional theory calculations with B3LYP/ CEP121G basis sets was used to determine ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies and infrared intensities for 2-chlorophenylisothiocyanate (CPIC) molecule . The assignments of the vibrational spectra have been carried out. The total energies, thermodynamic data, electronic states, energy gaps, ionization potentials, electron affinities, chemical potential, global hardness, softness, global electrophilicity, dipole moment and dipole polarizability and were calculated . The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The effects of Cl and NCS on the geometry of benzene and its normal modes of vibrations have also been studied. Finally the calculations results were applied to simulate infrared of the title compound which shows good agreement with observed spectra.