Spectroscopic and photochemical perturbations of weak interactions on electronic surfaces of methyl iodide

Abstract

Spectroscopic methods in concert with molecular-beam techniques can be used to study the effects of intermolecular interactions on reactive potential-energy surfaces. For these studies, we employ photoreactive molecules ‘embedded’ in small clusters. Spectroscopic and photochemical studies of isolated and clustered methyl iodide are described. The following effects are presented and discussed: intensity enhancement of forbidden electronic transitions by weak intermolecular interactions; predissociation dynamics on potential-energy surfaces perturbed by weak intermolecular interactions; the effect of weak van der Waals bonds on the chemistry of strong, covalent, bonds.

Small clusters of methyl iodide are shown to be ideal media for studying the perturbing effect of the environment on the reactive potential-energy surfaces of this molecule.