Xenon Expands Its Molecular Portfolio

The noble gases, which occupy the last column of the periodic table, were once thought to be inert and not capable of forming molecules. It has now been more than 50 years since that thinking has been debunked, and in that time an array of noble-gas compounds have been reported. Even so, when new versions are announced they are still considered noteworthy. In the latest examples, Gary J. Schrobilgen and his group at McMaster University, in Ontario, have reported two new types of xenon molecules. In one case, the researchers ran a reaction of XeF₂ with ReO₃F in anhydrous HF to prepare the bridging complex [XeOXeOXe][μ-F(ReO₂F₃)₂]₂. The cation is an unprecedented example of a xenon(II) oxide and noble-gas oxocation, as well as a rare example of a noble-gas dication (J. Am. Chem. Soc. 2015, DOI: 10.1021/jacs.5b08765). In a second case, the researchers treated the potent oxidant XeF₆ with acetonitrile in a chlorofluorocarbon solvent to make the shock-sensitive compounds F₆XeNCCH₃ and F₆Xe(NCCH₃)_2·CH₃CN. These are the first examples of molecules with Xe(VI)–N bonds (Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201507635). With X-ray crystal structures and computational analysis, the researchers provide additional insight into xenon’s electronic structure and bonding abilities.