Orientational effects in the direct Cl-+CH3Cl S(N)2 reaction at elevated collision energies: hard-ovoid line-of-centers collision model

The hard-sphere line-of-centers collision model can be extended analyticall y to include the orientational dependence of both the energy barrier and th e critical distance of approach. This hard-ovoid line-of-centers model is a pplied to the translational activation of the bimolecular nucleophilic subs titution (S(N)2) reaction, Cl- + CH3Cl --> ClCH3 + Cl-, for which a direct reaction mechanism was found in recent classical trajectory calculations. T he model is compared with recent experiments and the classical trajectory c alculations. (C) 1999 Elsevier Science B.V.