Crystals of the double salts Xe2F3MF3(XeF2)3AsF62 (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 MF3(XeF2)3+ adduct cations, which differ from all previously identified examples of XeF2 coordination to a metal(IV) center in their mononuclear and cationic nature, as well as in the coordination of multiple XeF2 ligands to a single metal(IV) center. Quantum-chemical calculations were performed to gain insight into the bonding and electronic structure of the MF3(XeF2)3+ adduct cations, with the optimized gas-phase geometries showing good agreement with the experimental solid-state structures. The characterized MF3(XeF2)3+ adduct cations markedly extend the chemistry of XeF2–MF4 systems and represent rare, crystallographically characterized examples of XeF2 coordination to PtIV and PdIV, a feature also believed to occur in the structure of the first discovered noble-gas compound, XePtF6. Moreover, the MF3(XeF2)3+ cations constitute the first examples of a new class of XeF2 coordination compounds, which are characterized by XeF2 ligation to a fluoridometal MFxn+ cation, thereby enabling further expansion of the coordination chemistry of noble-gas fluorides.
Motaln et al. (Thu,) studied this question.