A SIMPLE METHOD FOR QUANTITATIVE ESTIMATION OF C-H BOND LENGTHS IN HYDROCARBON RADICAL CATIONS

A quantitative correlation between deviations of the C-H bond lengths of hydrocarbon molecules during their adiabatic single ionization and isotropic hyperfine coupling constants with protons of their primary r adical cations (RC) was established. A simple method for estimation of the C-H bond lengths of hydrocarbon RC was proposed on the basis of t he correlation found. Specific features of the structure of the RC of methane and several n-alkanes of the general formula [H(CH2)(n)H*](.), n = 0 to 12, were analyzed. A widely used empirical rule, according to which deprotonation of hydrocarbon RC during the ion-molecular pro cess is determined by the proton possessing the highest spin density, was refined and geometrically substantiated.