Prototype Si-H Insertion Reaction of Silylene with Silane Absolute Rate Constants, Temperature Dependence, RRKM Modelling and the Potential-energy Surface

Time-resolved studies of silylene, SiH, , generated by laser flash photolysis of phenylsilane, have been carried out to obtain rate constants for its bimolecular reaction with monosilane, SiH4. The reaction was studied in t he gas phase over the pressure range 1-100 Torr, with both Ar and SF, as bath gases, at six temperatures in the range 298-665 K. The reaction of SiH, with SiH, to form disilane, Si,H,, is pressure dependent, consistent with a third-body assisted association reaction. The high-pressure rate constants, obtained by extrapolation, gave the Arrhenius equation : log(k"/cm3 molecule-' s' ) = (-9.91 f 0.04) + (3.3 f 0.3 kJ mol-')/RT In 10