Quasi-Atomic Bonding Analysis of Xe-Containing Compounds.

The origin of bonding in the rare-gas-containing molecules HXeCCH, HXeCCXeH, and HXeOXeH is explored using a quasi-atomic orbital (QUAO) analysis. The QUAOs provide qualitative and quantitative data about bonding through transformations of the density matrix. Bond orders, kinetic bond orders, and the extent of transfer of charge are analyzed. Localized molecular orbitals formed from the QUAOs provide additional insights about the relative polarity of bonds formed by xenon. The analysis suggests significant covalent bonding for Xe-Y (Y = C, O) as well as Xe-H, with both bonds using the same pσ-type orbital on Xe. These covalent interactions are established by substantial charge shifts from Xe to Y as well as to H. Accordingly, a covalent three-center four-electron bond links the atoms H-Xe-Y. On the basis of the analysis, electrostatic interactions do not play a significant role in the Xe-Y or Xe-H bonding.