ИСТИНА

Rare gas hydrides (HNgY, where Ng is a rare gas atom and Y is an electronegative fragment) are an interesting class of high-energy compounds with unusual chemical bond. The investigations of the mechanism of formation and decomposition of these molecules provide important information about the nature of a chemical bond, dynamics of atoms and radicals in rare-gas matrices and kinetics of chemical reactions at low temperatures. The most common way of obtaining rare gas hydrides is photodissociation of an appropriate precursor in a rare-gas matrix followed by controlled annealing[1]. Meanwhile, we have shown that the dissociation may be effectively produced using high-energy radiation (radiolysis)[2]. It is a promising way, especially for poor absorbers. The difference between photolysis and radiolysis may arise from different spatial distribution of the dissociation fragments[3]. In this work we present the results of recent studies of radiation chemical synthesis and stability of HXeSH, HXeH, HKrCl and HKrCCH and their isotopomers. The hydrides were prepared by X-ray irradiation of the deposited samples at 10 K or below followed by controlled annealing at different temperatures (20 to 45 K). It was revealed “local” and “global” reactions occurring at different temperatures. The possibility of controlling the scale of these processes was demonstrated with the example of HXeSH. Using mild IR photolysis it was possible to selectively produce close radical pairs from this species, which recover at very low temperatures. The isotopic effects in formation and decomposition of xenon and krypton hydrides are discussed; also the comparison with photochemical data for HKrCl[4] is presented. In general, we may conclude that the radiation-chemical approach is an effective way for producing and manipulating of rare gas hydrides. 1. Pettersson, M.; Lundell, J.; Räsänen, M. Eur. J. Inorg. Chem. 1999, 729–737; 2. Feldman, V. I.; Sukhov, F. F. Chem. Phys. Lett. 1996, 255, 425–430; 3. Feldman, V. I.; Sukhov, F. F.; Orlov, A. Yu.; Tyulpina, I. V. Mendeleev Commun. 2008, 18, 121–122; 4. Khriachtchev, L.; Saarelainen, M.; Pettersson, M.; Räsänen, M. J. Chem. Phys. 2003, 118, 6403–6410.