193 NM PHOTOLYSIS OF H2S IN RARE-GAS MATRICES - LUMINESCENCE SPECTROSCOPY OF THE PRODUCTS

The 193 nm photolysis of hydrogen sulfide (H2S) in solid rare gases is studied at 7.5 K. In order to get the most reliable data of the photo lysis process, Fourier transform (FT) infrared and time-resolved lumin escence methods are used in the same experiment. The 193 nm photolysis of H2S in Ar and Kr matrices was found to be very similar to the gas phase. A kinetic scheme of H2S photolysis, which is consistent with al l the experimental features, was constructed. The major channel is for mation of (H+SH) pairs, which are stabilized in the matrix. Then SH ra dicals decompose to (S+H) pairs, providing the main source for S atoms . No experimental evidence of a cage-induced reaction H + SH-->S+H-2 w as observed in our study, which can be connected with high probability for hydrogen-atom exit from the parent cage, and/or with high probabi lity of the recombination reaction H+SH-->H2S. The available spectrosc opic information for S atoms and SH radicals in Ar and Kr matrices is further specified, and new spectroscopic data on the photolysis produc ts in Ne and Xe matrices are reported. In particular, the luminescence data on SH radicals in solid rare-gas matrices (Ne, Ar, Kr, and Xe)we re found to resemble the tendencies known for OH radicals. Also, the i nfrared absorptions of SH radicals in Ar and Kr matrices were identifi ed to be at 2607 and 2594 cm(-1), respectively, and a novel rare-gas m olecule HXeSH with the Xe-H stretch at 1119 cm(-1) was detected. (C) 1 998 American Institute of Physics.