Laser-Excited Fluorescence Detection of SiH2 Producted in IR MPD (Infrared Multiple-Photon Dissociation) of Organosilanes

摘要

Silicon Hydride has been identified as a photolysis product in the infrared multiple photon dissociation of RSiH3 (R = n-butyl, phenyl), arising from secondary IR MPD of silane produced in the initial four-center elimination step. The radiative lifetimes of levels show a strong rotational state dependence. The infrared multiple photon dissociation (IR MPD) of organosilanes has been observed to yield olefins, silane, and a deposit of adjacent surfaces identified as amorphous silicon (a:Si-H). The low silane olefin product ratios found in those experiments, and the accompanying deposition of a:Si-H, were attributed to secondary IR MPD of the vibrationally hot silane produced in the initial photolysis steps to yield silylene (SiH2). In order to verify this proposed mechanism, we have used laser excited fluorescence (LIF) to detect the SiH2 produced in this reaction.