Neutral rare-gas containing charge-transfer molecules in solid matrices. II. HXeH, HXeD, and DXeD in Xe

Photolysis of hydrogen halides (and some other hydrogen containing small molecules) in solid Xe yields in a two step process charged centers, one of them being XeHXe+. Annealing of the irradiated doped solids produces, in addition to H–Xe–Y (Y=Cl, Br, or I) species characterized by us previously, a fairly strong doublet at 1181 and 1166 cm−1 and a weak absorption at 701 cm−1. Deuterated precursors yield a doublet at 846 and 856 cm−1. Also peaks belonging to mixed H/D form are found, indicating that the absorbing species contains two H/D atoms. The new species responsible for these absorptions are assigned as neutral linear centrosymmetric HXeH, HXeD, and DXeD. The nature of the bonding can be understood in terms of the resonance between the two ionic forms HXe+H− and H−Xe+H, analogously to the valence bond description of the well known XeF2. The pseudopotential (LANL1DZ) ab initio calculations at the MP2 level are in good agreement with the observed spectra.