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

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