XeF2 Coordination Complexes of the [BrO2]+ Cation, [O2Br(FXeF) n ][AsF6] (n=1, 2) and [O2Br(FXeF)2][SbF6]; Their Syntheses and Structural Characterizations

Xenon difluorideand [BrO2]-[PnF(6)](Pn = As, Sb) react at low temperatures in anhydrous HF to form theBr-(V) coordination complexes, [O2Br-(FXeF)]-[AsF6] and [O2Br-(FXeF)(2)]-[PnF(6)], whichwere structurally characterized at low temperatures by single-crystalX-ray diffraction and Raman spectroscopy. Secondary Br---F bonds betweenBr-(V) and the F atoms of the XeF2 and [PnF(6)](-) are directed toward sigma-holes on Br-(V) and havetrajectories that avoid the stereoactive valence electron lone-pairof Br-(V). The syntheses and structural characterizations of thefirst XeF2 coordination complexes of the [BrO2](+) cation are described. The reactions of [BrO2]-[PnF(6)] (Pn = As, Sb) with XeF2 in anhydrousHF solventyield the salts [O2Br-(FXeF)( n )]-[AsF6] (n = 1, 2) and [O2Br-(FXeF)(2)]-[SbF6], which were characterizedby low-temperature (LT) Raman spectroscopy and single-crystal X-raydiffraction (SCXRD). The XeF2 ligands and [PnF(6)](-) coordinate to the Lewis acidic [BrO2](+) cation through primarily electrostatic Br-V---F-Xe sigma-hole bonds that result from coordinationof the F atoms into regions of high positive electrostatic potentialon the Br-(V) atom and have bond trajectories that avoid the stereoactivevalence electron lone-pair of Br-(V). The complexes and their structuralcharacterizations by LT Raman spectroscopy and SCXRD significantlyextend the coordination chemistry of Br-(V) and provide rare examplesof a noble-gas difluoride coordinated to a strong oxidant main-groupLewis acid center.

Automated summary

Xenon difluoride and [BrO2]-[PnF(6)] (Pn = As, Sb) react to form Br-(V) coordination complexes, which are characterized by X-ray diffraction and Raman spectroscopy. Secondary Br---F bonds between Br-(V) and XeF2, [PnF(6)](-) are formed through sigma-hole interactions and avoid the stereoactive valence electron lone-pair of Br-(V). The synthesis and structural characterization of the first XeF2 coordination complexes of [BrO2](+) cation are described. The coordination chemistry of Br-(V) is extended and rare examples of a noble-gas difluoride coordinated to a strong oxidant main-group Lewis acid center are provided.