The electronic spectra of jet-cooled HGeCl and HGeBr

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 (HGeX or DGeX). All three excited state vibrational frequencies have been obtained for each of the four molecules. Analysis of the rotational structure of the 0 bands of the ÃA″-X̃A′ band system allowed the determination of r structures in the ground and excited states, with the bond angles constrained to previous ab initio values. The results for HGeCl are: r″(Ge-Cl) = 2.171 (2) Å, r″(H-Ge) = 1.592(1) Å, θ″(HGeCl) = 94.3°, r′(Ge-Cl) = 2.146(15) Å, r′(H-Ge)= 1.613(2) Å, θ′(HGeCl) =114.5°; and for HGeBr: r″(Ge-Br) = 2.329(12) Å, r″(H-Ge)= 1.598(6) Å, θ″(HGeBr) = 93.9°, r′(Ge-Br) = 2.308(1) Å, r′(H-Ge) = 1.615(1)Å, and θ′(HGeBr) = 116.3°. The radiative lifetimes of the ÃA″ states of HGeCl and HGeBr have been measured to be 548±19 ns and 736±24 ns, respectively. © 1998 American Institute of Physics.