Reactions of SiH 2(X̄ 1A 1) with H 2, CH 4, C 2H 4, SiH 4 and Si 2H 6 at 298 K

Abstract

Reaction rate constants of SiH 2(X̄ 1A 1) have been directly measured for the first time using the laser photolysis—laser-induced fluorescence method. The preparation of SiH 2 radical in the laser photolysis (193 nm) of phenylsilane and the concentration of the radical is demonstrated by a dye laser at 580.1 nm (X̄ 1A 1-Ā 1B 1). The reaction rate constants of SiH 2(X̄ 1A 1) with H 2, CH 4, C 2H 4, SiH 4 and Si 2H 6, are 0.001, 0.01, 0.97, 1.1 and 5.7×10 −10 cm 3 molecule −1 s −1, respectively. For SiH 2(Ā 1B 1(0.2,0)), the collision-free lifetime is 0.6 μs and the quenching rate constant for He is 3.8×10 −10 cm 3 molecule −1 s −1.