CHARGE OSCILLATION IN THE HOMOLYSIS OF MEX DERIVATIVES

Ab initio electronic structure methods are used to show that, in the (barrierless) homolytic dissociation of the CH3X system (X = an atom or group more electronegative than CH3) going from equilibrium geometry to products (CH3. + X.), the charge on CH3 first increases and then decreases to zero. This result, which can be rationalized on the basis of simple models, violates the common assumption that the character of intermediates along a reaction path is bound by the properties of reactants and products. The implications of this new conclusion to kinetic/thermodynamic data relationships in chemical reactions are discussed.