LIBRATIONAL CONTROL OF PHOTOCHEMICAL-REACTIONS IN SMALL CLUSTERS

A novel approach to the enhancement of photochemical reaction yield in hydrogen-containing clusters is outlined and applied to the process o f the Cl-2 molecule formation from a UV-photolyzed Cl ... HCl species. The control mechanism consists of a far-IR preexcitation of the large -amplitude hydrogenic bending (librational) mode prior to the HCl phot odissociation. Molecular dynamics simulations that properly sample the initial quantum state of the system show that this leads to more than a factor of 2 enhancement of the Cl-2 yield both in the parent and de uterated clusters.