A Neutral Xenon-Containing Radical, HXeO

Abstract

We report an open-shell species containing xenon, HXeO ((2)Sigma), prepared by UV photolysis of H(2)O/Xe or N(2)O/HBr/Xe solid mixtures at 7 K and subsequent thermal mobilization of oxygen atoms at >/=30 K. The H-Xe stretching absorption of HXeO in solid Xe is at 1466.1 cm(-1), and it shifts to 1070.3 cm(-1) upon deuteration. The extensive ab initio calculations indicate that HXeO is intrinsically stable, owing to significant ionic and covalent contributions to its bonding. The formation of HXeO ((2)Sigma) radicals in these experiments suggests extensive stabilization and thermal mobility of singlet ((1)D) oxygen atoms in solid Xe and holds promises for the stability of the HKrO and HArO species.

Matrix-Isolation Studies on the Radiation-Induced Chemistry in H2O/CO2 Systems: Reactions of Oxygen Atoms and Formation of HOCO Radical

“…The appearance of formyl radical (peaks at 1863. 5 56 were observed in IR spectra after warming the samples to higher temperatures (26,33, and 45 K for Ar, Kr, and Xe matrices, respectively). The corresponding annealing dependencies are presented in Figure 5.…”

“…25 On the other hand, it was found that formation of the HXeO radical was determined by reactions of mobile oxygen atoms in xenon. 26,27 Thus, the IR spectroscopic studies of formation of different xenon hydrides allow one to follow the dynamics and reactivity of both hydrogen and oxygen atoms.…”

The radiation-induced chemistry in solid xenon matrices

“…3, the first scheme (a two-stage dissociation of H 2 O) works quite well: the IR spectrum obtained after annealing of H 2 O/Xe sample irradiated with fast electrons to high dose reveals a well-defined band of the HXeO . radical (maximum at 1466 cm -1 [62]). In the case of N 2 O, one needs an additional source of H atoms.…”

“…We have used several different hydrogenated molecules for this purpose. The common procedure was similar to that used in photochemical studies [62]: irradiation of the system HY/N 2 O/Xe at low temperature following by annealing at 35 K to mobilize selectively trapped O atoms. However, in contrast to photolysis, the radiation-chemical experiments yield virtually no HXeO .…”

Atypical Compounds of Gases, which Have Been Called “Noble”

“…5(e),(f)). 52 Obviously, eqn (12)-(17) might be infinitely modified and extended to derivatives of C, N, S, Cl etc. Notably, studies of the thermal stability of the reaction products (on warming of the matrix) would show how realistic is the prospect of obtaining these and related species in larger quantities 'in the flask'.…”