For decades chemists have known that noble gases can subvert their name by forming chemical compounds. No compound demonstrates this point as emphatically as HXeOXeH, a molecule prepared by Leonid Khriachtchev at the University of Helsinki in Finland and his colleagues.
The compound is almost unique in containing two noble-gas atoms in a single, small molecule, and is possibly the simplest molecule of this type. The structure is like that of a water molecule with a xenon atom inserted into both of the bonds between oxygen and hydrogen. HXeOXeH forms in a photochemical reaction between xenon and water at 45 kelvin. The researchers hope their finding will be the first step towards designing polymers with alternating xenon and oxygen atoms.