Dissociative Photodetachment Dynamics of Solvated Iodine Cluster Anions

Photoelectron-photofragment coincidence spectroscopy of I -(CO 2), I -(NH 3), I -(H 2O), I -(C 6H 5NH 2), and I -(C 6H 5OH) clusters was used to study the dissociative photodetachment (DPD) dynamics at 257 nm. Photodetachment from all five clusters was observed to yield bound neutral clusters as well as the DPD products of the iodine atom and the molecular solvent. Photoelectron images and kinetic energy spectra were recorded in coincidence with both the translational energy released between dissociating neutral products and stable neutral clusters. The variation of the photoelectron angular distributions in the clusters was measured, revealing significant perturbations relative to I - for I -(H 2O) and I -(C 6H 5NH 2). Product branching ratios for stable versus dissociative photodetachment and photodetachment to the I( 2P 3/2) and I( 2P 1/2) states are reported. The measurements reveal a dependence of the DPD dynamics on the final spin-orbit state of iodine in the cases of I -(C 6H 5NH 2) and I -(CO 2) and a threshold detachment process in I -~(C 6H 5NH 2).