PHOTOGENERATION OF IONIC SPECIES IN AR, KR AND XE MATRICES DOPED WITH HCL, HBR AND HI

Photogeneration of Ar2H+, Kr2H+ and Xe2H+ and their deuterated counterparts is reported in H(D)Cl doped Ar, and H(D)X(X=Cl, Br or I) doped Kr and Xe matrices, respectively. The formation of these species is ascribed to optical access of the delocalized X/rare gas charge transfer states, and subsequent charge trapping processes. Once generated, the absorptions of the cations bleach thermally at low temperatures (12 K). The observed second-order decay kinetics is discussed in terms of charge-recombination involving a distribution of barrier heights. The deuterated cations bleach on a significantly longer timescale. Bihalide ions, HX(2)(-), of D-proportional to h symmetry are the other products formed in the photolysis. Annealing of the extensively irradiated HCl, HBr and HI doped xenon and HCl doped krypton yields strong infrared absorptions in the 1200-1600 cm(-1) spectral region. These bands are tentatively ascribed to linear asymmetric (X-H-X)- ions perturbed by a nearby positive charge, or to (XeHX)(+) and (KrHX)(+) species.