Conformational and vibrational spectroscopic investigation of N-n‑butyl, S-2-nitro-1-(p-tolyl)ethyl dithiocarbamate – a bio-relevant sulfur molecule

Abstract

This work describes the synthesis, conformational, thermodynamics and vibrational spectroscopic studies of N-n‑butyl, S-2-nitro-1-(p-tolyl)ethyl dithiocarbamate, a bio-relevant sulfur molecule. A total of seven low lying energy structures of N-n‑butyl, S-2-nitro-1-(p-tolyl)ethyl dithiocarbamate are theoretically predicted. The quantum chemical calculations were performed using Gaussian09 with the 6–31++G(d,p) basis set. This basis set has been shown to reproduce the experimental structural and vibrational properties of N-n‑butyl, S-2-nitro-1-(p-tolyl)ethyl dithiocarbamate. The infrared spectrum was recorded from sample in Kbr pellet in the range 400 to 4000cm−1 with a spectral resolution of 4cm−1and this correlates well with the theoretical spectra of the most stable conformer. The potential energy distribution of the most stable conformer was calculated by employing the normal coordinate analysis method. The natural bond orbital analysis (NBO) of the most stable conformer was done to study the donor-acceptor interactions and stability of the electronic structure. The different thermodynamical parameters, viz, entropy, specific heat, free and thermal energy are also estimated and discussed. The frontier bond orbital analysis has been studied to explore the transition profile of the molecule. Moreover, the structure-property relationship and molecular docking study with methyltransferase group of enzymes have been performed.