Spectroscopic and quantum mechanical investigations of (2E)-3-(2H-1,3-benzodioxol-5-yl)-N-phenylprop-2-enamide using density functional theory method

Abstract

The Fourier transform infrared (FTIR) and FT-Raman of (2E)-3-(2H-1,3-benzodioxol-5-yl)-N-phenylprop-2-enamide (2BNP2E) have been recorded in the regions 4000-100 and 4000-450cm-1, respectively. A complete assignment and analysis of the fundamental vibrational modes of the molecule have been carried out. The observed fundamental modes have been compared with the harmonic vibrational frequencies computed using DFT (B3LYP) method by employing 6-311++G(d,p) basis set. The vibrational studies have been interpreted in terms of potential energy distribution. The first order hyperpolarizability (β0) and related properties (α, μ and ∆α) of this molecular system are calculated using B3LYP/6-311++G(d,p) method based on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ* and π* anti-bonding orbitals and second-order delocalization energies (E(2)) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. Molecular electrostatic potential (MEP) and HOMO-LUMO energy levels have also been constructed. The thermodynamic properties of the title compound have been calculated at different temperature and the results reveal that the standard heat capacity C, entropy S and enthalpy changes H increase with rise in temperature.