THEORETICAL-STUDY ON CH2CNH CH3CN - ISOMERIZATION REACTION IN SMALL CLUSTERS CONTAINING H2O MOLECULES/

We investigated the effect of water molecules on the isomerization rea ction of ketenimine yielding acetonitrile. The molecular structures we re optimized at Hartree-Fock and MP2 levels. Up to 3 H2O molecules wer e explicitly taken into account. In the CH2CNH-H2O complexes the isome rization reaction proceeds in a concerted one step mechanism. One and two H2O molecules directly catalyze the reaction. The activation barri ers are drastically lowered. Although a third H2O molecule does not di rectly join the intermolecular hydrogen exchange, it still further sta bilizes the transition state.