Effect of polarity and steric on the rate addition of free radicals to Alkenes

Abstract

In this investigation, the effective factors on the addition rate for hydroxy methyl and cynomethyl free radicals to some alkenes have been studied using quantum mechanics methods. Where in this study, physical properties like the electron density on the two carbon atoms which participate in the free radical addition on alkene has been studied. These two carbon atoms are: the one which hold the single electron in the free radical and the second which is the unsubstituted carbon in the alkene. Also, the energy level HOMO, LUMO and SOMO have been calculated. In addition, the relations between the log of the addition rate constant of the free radical into the alkene and the electronic properties mentioned above have been investigated. The results have shown that the polarity, ionization potential, the energy levels HOMO & LUMO and the steric hinderance are the main effective factors in the determination of the addition rate constant for the free radicals into the alkenes