The electronic spectra of jet-cooled HGeCl and HGeBr

Abstract

Laser-induced fluorescence spectra of jet-cooled HGeCl, DGeCl, HGeBr, and DGeBr have been obtained using the pulsed discharge technique. The germylenes were produced by an electric discharge through argon seeded with the appropriate monohalogermane (H3GeX or D3GeX). All three excited state vibrational frequencies have been obtained for each of the four molecules. Analysis of the rotational structure of the 000 bands of the à 1A″–X̃ 1A′ band system allowed the determination of r0 structures in the ground and excited states, with the bond angles constrained to previous ab initio values. The results for HGeCl are: r0″(Ge–Cl)=2.171(2) Å, r0″(H–Ge)=1.592(1) Å, θ0″(HGeCl)=94.3°, r0′(Ge–Cl)=2.146(15) Å, r0′(H–Ge)=1.613(2) Å, θ0′(HGeCl)=114.5°; and for HGeBr: r0″(Ge–Br)=2.329(12) Å, r0″(H–Ge)=1.598(6) Å, θ0″(HGeBr)=93.9°, r0′(Ge–Br)=2.308(1) Å, r0′(H–Ge)=1.615(1) Å, and θ0′(HGeBr)=116.3°. The radiative lifetimes of the à 1A″ states of HGeCl and HGeBr have been measured to be 548±19 ns and 736±24 ns, respectively.