Quantum chemical calculations of conformation, vibrational spectroscopic, electronic, NBO and thermodynamic properties of 2,2-dichloro-N-(2,3-dichlorophenyl) acetamide and 2,2-dichloro-N-(2,3-dichlorophenyl) acetamide

The molecular structural parameters, thermodynamic properties and vibrational frequencies of the fundamental modes of 2,2-dichloro-N-(2,3-dichlorophenyl) acetamide (2,3CPA) and 2,2-dichloro-N-(2,4-dichlorophenyl) acetamide (2,4CPA) have been obtained using density functional theory (DFT) technique in the B3LYP approximation and 6-311G(d,p) basis set. Detailed vibrational assignments of the observed FTIR and FT Raman bands have been proposed on the basis of potential energy distribution (PED). Most of the modes have wavenumbers in the expected range. The molecular electrostatic potential has been mapped primarily for predicting sites and relative reactivities towards electrophilic and nucleophilic attack. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been studied by natural bond orbital (NBO) analysis. Absorption wavelengths and their assignments in UV–vis region have been predicted, based on time-dependent density functional theory (TD-DFT) calculations. The temperature dependence of thermodynamic properties has been analyzed. Global and local reactivity descriptors have been calculated in order to have a deep insight into the molecule for further applications.