DFT investigation of pachypodol for exploring anti-oxidant action – Performance of B3LYP and M06-2X

Abstract

Anti-oxidant mechanism of the pachypodol is computed with the aid of density functional theory (DFT) in the light of B3LYP (B3, Lee-Yang-Parr correlation function) and M06-2X (highly parameterized, exchange correlation function) using 6-311G(d,p) basis set in the Gaussian 09 software package. This investigation aims to prove the better reaction enthalpies among hydrogen atom transfer (HAT), sequential proton-loss electron-transfer (SPLET) and single electron transfer-proton transfer (SET-PT) in gas and solvent phases with both the level of theories (B3LYP and M06-2X). The result shows that the preferred anti-oxidant mechanism is found to be HAT in both gas and solvent phases. The analysis of bond dissociation enthalpy (BDE) has been carried out in gas and solvent phases. Molecular descriptors are analyzed and computed in the light of both the level of theories. The radical scavenging of pachypodol is well established with B3LYP theory, since it yields appreciable results with respect to BDE, IP and PDE than M06-2X level of theory. Fukui function of the compound is performed using both the level of theories and preferred electrophilic and nucleophilic sites of pachypodol are analyzed. The weak and strong intramolecular bonds are examined with the aid of NBO.