Coordination of XeF[sub]2 to fluoridometal cations: the adduct cations [PtF[sub]3(XeF[sub]2)[sub]3][sup]+ and [PdF[sub]3(XeF[sub]2)[sub]3][sup]+

Crystals of the double salts [Xe 2 F 3 ][MF 3 (XeF 2 ) 3 ]-[AsF 6 ] 2 (M = Pd, Pt), prepared from anhydrous HF solutions, were characterized by low-temperature single-crystal X-ray diffraction and Raman spectroscopy.The crystal structures reveal that the compounds contain the hitherto unobserved [MF 3 (XeF 2 ) 3 ] + adduct cations, which differ from all previously identified examples of XeF 2 coordination to a metal(IV) center in their mononuclear and cationic nature, as well as in the coordination of multiple XeF 2 ligands to a single metal(IV) center.Quantum-chemical calculations were performed to gain insight into the bonding and electronic structure of the [MF 3 (XeF 2 ) 3 ] + adduct cations, with the optimized gas-phase geometries showing good agreement with the experimental solid-state structures.The characterized [MF 3 (XeF 2 ) 3 ] + adduct cations markedly extend the chemistry of XeF 2 -MF 4 systems and represent rare, crystallographically characterized examples of XeF 2 coordination to Pt IV and Pd IV , a feature also believed to occur in the structure of the first discovered noble-gas compound, XePtF 6 .Moreover, the [MF 3 (XeF 2 ) 3 ] + cations constitute the first examples of a new class of XeF 2 coordination compounds, which are characterized by XeF 2 ligation to a fluoridometal [MF x ] n+ cation, thereby enabling further expansion of the coordination chemistry of noble-gas fluorides.