QUANTUM MECHANICAL STUDIES OF THE KINETICS, MECHANISMS AND THERMODYNAMICS OF THE GAS-PHASE THERMAL DECOMPOSITION OF ETHYLVINYL ETHER

Abstract

The thermal decomposition of Ethyl Vinyl Ether was studied using Austin Model (AMI), Re-parameterized Austin Model (RMI), Parameterized Model 3 (PM#) and Modified Neglect of Diatomic Overlap (MNDO) Hamiltonian in the Semi-Empirical method, Hartree-Foch at 3-21G,6-31G*, 6-31G** level, and Density Functional method with Becke 3 Lee Yang Parr (B3LYP), 6-31G* in the Ab-initio method of calculation in Spartan '10. The geometric properties such as the bond length, dihedral, bond angles, heat of formation, atomic charges, and vibrational frequencies were obtained. The data were used to calculate the change in enthalpy delta H, entropy deltaS, free energy delta G, pre-exponential factor A, Rate, K at 624K, and the variation of rate, K with temperatures at 498K - 773K at temperature interval of 25K. It was observed that the values obtained are in good agreement with experimental values for both semi-empirical and ab-initio methods and according to Arrhenius Theory, calculated rate K, increases with an increase in temperature.