Computational Studies on the Thermodynamic and Kinetic Parameters of Unimolecular and Bimolecular Dissociation of Propylene Glycol Ethyl Ether in Binary 1-Butanol and Isobutanol Solvent Mixtures

This study includes a theoretical investigation of Thermodynamic and kinetics of the unimolecular and bimolecular dissociation reaction of Propylene Glycol Ethyl Ether in the gaseous phase. A B3LYP functional with 6-31G(d) basis set was used to optimize all geometries of the stationary points. Potential-energy surface for various channels for the reaction of PGEE was studied at APFD/6-31G(d) and omega B97XD/6-31G(d) levels of theory. The kinetic and thermodynamic parameters for nineteen reaction pathways are investigated. Most of the unimolecular dissociation mechanisms occur in a concerted transition state step endothermically. Our calculations proved that energy barriers for ethanol and acetone formation is the best reaction route with an activation barrier of 279 kJ mol-1 at APFD/6-31G(d) level of theory. The PGEE bimolecular reaction with 1-butanol, the pathway which produces H2 and butanal is more plausible to take place with a lower activation energy of 225 kJ mol-1 at omega B97XD/6-31G(d) level of theory.