Infrared multiple photon dissociation of dichlorosilane: The production of electronically excited SiCl2

The infrared multiple photon excitation of SiH₂Cl₂, under collision-free and collisional conditions, via its v₂(a₁) SiH₂ bending fundamental resulted in dissociation and in an ultraviolet luminescence. The photodissociative products were found to be H₂ and SiCl₂ while the luminescence was shown to arise from a spontaneous one-photon radiative decay from electronically excited SiCl₂(¹B₁ → ¹A₁). The radiative lifetime of this transition has been measured as 4.5 μs and the collisional quenching rate of SiCl₂(¹B₁ → ¹A₁) by SiH₂Cl₂ as 2.6 × 10⁶ s^?1 Torr^?1. The reaction mechanism leading to product formation as well as models for populating the electronic state of the fragment are proposed and discussed in conjunction with present multiple photon dissociation theory.