Time-resolved gas-phase kinetic, quantum chemical and RRKM studies of the reaction of silylene with 2,5-dihydrofuran

Time-resolved kinetics studies of silylene, SiH2, generated by laser flash photolysis of phenylsilane, were performed to obtain rate coefficients for its bimolecular reaction with 2,5-dihydrofuran (2,5-DHF). The reaction was studied in the gas phase over the pressure range of 1–100 Torr in SF6 bath gas, at five temperatures in the range of 296–598 K. The reaction showed pressure dependences characteristic of a third body assisted association. The second-order rate coefficients obtained by Rice–Ramsperger–Kassel–Marcus (RRKM)-assisted extrapolation to the high-pressure limit at each temperature fitted the following Arrhenius equation where the error limits are single standard deviations: log(k/cm3 molecule–1 s–1) = (−9.96 ± 0.08) + (3.38 ± 0.62 kJ mol–1)/RT ln 10. End-product analysis revealed no GC-identifiable product. Quantum chemical (ab initio) calculations indicate that reaction of SiH2 with 2,5-DHF can occur at both the double bond (to form a silirane) and the O atom (to form a donor–acceptor, zwitt...