Isomerization study of C₅H₅NO molecules

Abstract

ABSTRACT:The complex potential energy surface (PES) for the isomerization of C 5 H 5 NO species, including 18 isomers and 23 interconversion transition states, is probed theoretically at the B3LYP/6-311ϩϩG(d,p) and MP2//B3LYP/6-311ϩϩG(d,p) levels of theory. The geometries and relative energies for various stationary points were determined. The zero-point vibrational energy (ZPVE) corrections have been made to calculate the reliable energy. We predicted a six-membered ring structure as a global minima isomer I, which is 118.49 and 131.48 kcal ⅐ mol Ϫ1 more stable than the least stable, four-and three-membered ring isomer VIII at B3LYP and MP2//B3LYP levels of theory, respectively. The isomers and interconversion transition states have verified by frequency calculation. The intrinsic reaction coordinates (IRC) calculations have been performed to confirm that each transition state is linked by the desired reactants and products. The isomer stability has been studied using relative energies, chemical hardness, and chemical potential.