Detection and Characterization of Singly Deuterated Silylene, SiHD, Via Optical Spectroscopy

Singly deuterated silylene has been detected and characterized in the gas-phase using high-resolution, two-dimensional, optical spectroscopy. Rotationally resolved lines in the 0[0 over 0][˜ over X]¹A′ → [˜ over A]¹A′′000X˜1A′→A˜1A″ band are assigned to both c-type perpendicular transition and additional parallel, axis-switching induced bands. The extracted rotational constants were combined with those for SiH₂ and SiD₂ to determine an improved equilibrium bond length, r_SiH, and bond angle, θ, of 1.5137 ± 0.0003 Å and 92.04° ± 0.05°, and 1.4853 ± 0.0005 Å and 122.48° ± 0.08° for the [˜ over X]¹A′(0, 0, 0) and [˜ over A]¹A″(0, 0, 0) state respectively. The dispersed fluorescence consists of a long progression in the [˜ over A]¹A″(0,0,0) → [˜ over X]¹A′(0, ν₂, 0) emission which was analyzed to produce vibrational parameters. A strong quantum level dependence of the rotationally resolved radiative decay curves is analyzed.