Neutral Reactions in the Presence of Alkali Ions

摘要

It has previously been shown that neutral ligands clustered to an alkali ion can react with other neutrals. In fact, the presence of the alkali ion greatly enhances the rate of the corresponding neutral-neutral reaction. Several more reactions that exhibit this phenomenon have been identified experimentally, with rate enhancements ranging from 4 to 30 orders of magnitude. Three possible explanations for the rate enhancement have been explored. Ab initio calculations have been carried out to supplement the experimental measurements and to provide further insight into the mechanism. The calculations indicate that bonding the neutral to the alkali ion causes structural rearrangements that shift the geometry of the neutral molecule toward its transition state geometry in the corresponding neutral-neutral reaction, thereby lowering the activation energy of the reaction. Keywords: Alkali metal clusters, Rate enhancement, Ab initio calculations.