Synthesis, Structure, and Bonding of a Xe Transition-Metal Coordination Complex, F XeF - - -WOF.

The coordination complex, F XeF - - -WOF , was synthesized in CFCl solvent by reaction of the weak fluoride-ion donor and strong oxidative fluorinating agent, XeF , with the moderate-strength fluoride-ion acceptor, WOF . The compound is the only transition-metal coordination complex of Xe and was characterized at low temperatures by single-crystal X-ray diffraction and Raman spectroscopy. Xenon tetrafluoride and WOF coordinate trans to the W=O bond through a W- - -F bond. The XeF moiety of F XeF - - -WOF acquires a degree of [XeF ] character upon coordination that is reflected by its Xe-F stretching frequencies which are intermediate with respect to those of XeF and [XeF ] . Calculations show W- - -F is predominantly an electrostatic, σ-hole bond with a significant orbital contribution that accounts for the bent Xe-F - - -W angle. The calculations show F XeF - - -MOF (M=Cr, Mo) are less stable than their W analogue, consistent with failed attempts to synthesize F XeF - - -MoOF .