Synthesis and Homomolecular Metalation of Trialkylsilylphosphanides of Calcium and Barium

The synthesis of novel neutral rare-gas-containing molecules of type HXY, where X = Xe or Kr and Y is an electronegative atom or fragment, is discussed. The molecules are characterised experimentally by their vibrational spectra and computationally by extensive ab initio calculations. They are formed in low-temperature rare-gas solids from neutral reagents and their bonding consists of both covalent and ionic contributions. Our recent studies add to the previously known class of rare-gas chemical bonds in neutral ground-state molecules the new bonds Xe-H, Xe-I, Xe-Br, Xe-S, Kr-H, Kr-C, and Kr-Cl.