Two Xenons In One Small Molecule

To date, most molecules involving noble gases, such as KrF₂ or HXeCl, contain just one of the inert atoms and frequently some halide atoms. Now, Leonid Khriachtchev of the University of Helsinki and colleagues have synthesized what they believe is the smallest neutral molecule with two noble-gas atoms, HXeOXeH (J. Am. Chem. Soc., DOI: 10.1021/ja077835v). Khriachtchev's team—which, in 2003, also produced the first noble-gas hydride containing two xenon atoms, HXeCCXeH—used computational methods that predict that the new molecule is bent, with an Xe–O–Xe angle of 138.2°. Their synthesis, which involved UV photolysis of water in solid xenon, gives scientists a new opportunity to study the unusual properties of Xe–O bonds. The discovery, the authors note, could also have some bearing on the "missing xenon" problem, a long-standing mystery in which Earth appears to contain less xenon than other terrestrial planets. Some theories hold that xenon could be sequestered inside Earth's core, perhaps by reacting under high temperature and pressure.