Use of semi empirical method for determination of the activation energy of thermal decomposition of vinyl ethers

Abstract

In this research, a semi empirical approach has been suggested for calculating the activation energy<br />of unimolecular thermal decomposition of vinyl ethers yielding saturated products. The calculation<br />procedure is based on the use of molecular mechanics (MM) methods. These methods which involve<br />the construction of the transition state for a molecule mainly consider the formation of a “Hydrogen<br />Bridge" between the alkyl and vinyl groups and also use the Lennard - Jones potential. The<br />activation energy of the decay is calculated as the difference between bond energy of the Hydrogen<br />atom jumping from the alkyl group to the vinyl group, and the strain energy of the molecule due to<br />the formation of the transition state (TS). A new semi empirical method for computing the activation<br />energy at spontaneous decay of vinyl ethyl ether (VEE), vinyl propyl ether (VPE) and vinyl butyl<br />ether (VBE) molecules has been developed. It allows calculating the values of the activation energy<br />by simple procedures. The obtained results for the decay of vinyl ethers are in good agreement with<br />the known experimental data in the literature.