Xenon Trioxide Adducts of O‐Donor Ligands; [(CH₃)₂CO]₃XeO₃, [(CH₃)₂SO]₃(XeO₃)₂, (C₅H₅NO)₃(XeO₃)₂, and [(C₆H₅)₃PO]₂XeO₃

Abstract

Xenon trioxide (XeO3) forms adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine‐N‐oxide, and acetone by coordination of the ligand oxygen atoms to the XeVI atom of XeO3. The crystalline adducts were characterized by low‐temperature, single‐crystal X‐ray diffraction, and Raman spectroscopy. Unlike solid XeO3, which detonates when mechanically or thermally shocked, solid (C5H5NO)3(XeO3)2, [(C6H5)3PO]2XeO3, and [(CH3)2SO]3(XeO3)2 are insensitive to mechanical shock. The [(CH3)2SO]3(XeO3)2 adduct slowly decomposes over several days to (CH3)2SO2, Xe, and O2. All three complexes undergo rapid deflagration when ignited by a flame. Both [(C6H5)3PO]2XeO3 and (C5H5NO)3(XeO3)2 are room‐temperature stable and the [(CH3)2CO]3XeO3 complex dissociates at room temperature to form a stable solution of XeO3 in acetone. The xenon coordination sphere of [(C6H5)3PO]2XeO3, a distorted square‐pyramid, provides the first example of a five‐coordinate XeO3 complex with only two Xe‐ ‐ ‐O adduct bonds. The xenon coordination spheres of the remaining adducts are distorted octahedra, comprised of three Xe‐ ‐ ‐O secondary bonds that are approximately trans to the primary Xe−O bonds of XeO3. Quantum‐chemical calculations were used to assess the nature of the Xe‐ ‐ ‐O adduct bonds, which are described as predominantly electrostatic bonds between the nucleophilic oxygen atoms of the bases and the σ‐holes of the electrophilic xenon atoms.

Computational Study of Selected Amine and Lactam N-Oxides Including Comparisons of N-O Bond Dissociation Enthalpies with Those of Pyridine N-Oxides

“…The Meisenheimer and Cope reactions utilize the thermal labile nature of the N-O bond, in order to undergo a rearrangement to form an N-N-disubstituted hydroxylamines [1]. Interestingly, pyridine N-oxide forms a crystalline complex with xenon trioxide that is much less prone to explosion upon thermal or mechanical shock than XeO 3 itself [6]. Pyridine N-oxide and other heterocyclic N-oxides play significant roles in drug metabolism and as pro-drugs [3,4,7,8].…”

Noble Gas Bonding Interactions Involving Xenon Oxides and Fluorides

“…Therefore, it exhibits a strong tendency to form directional noncovalent interactions as exemplified by its X–ray solid state structure represented in Figure 2 . Several investigations by Schrobilgen’s group have further demonstrated the ability of XeO 3 to act as Lewis acid and have evidenced the importance of NgBs in the solid state of several adducts [ 111 , 112 , 113 ]. For instance, halide salts of general formulae [N(C 2 H 5 ) 4 ] 3 [X 3 (XeO 3 ) 3 ]; X = Cl, Br were synthesized and X-ray characterized (see Figure 11 ) at low temperature [ 98 ].…”

“…The low-temperature, single-crystal X-ray characterization of XeO 3 adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine-N-oxide, and acetone by the formation of NgBs has been recently reported (three of them represented in Figure 14 ) [ 113 ]. These interactions give stability to the otherwise easy to detonate XeO 3 solid.…”

Noble-Gas Chemistry More than Half a Century after the First Report of the Noble-Gas Compound

“…The crystalline adducts of XeO 3 with triphenylphosphine oxide, dimethylsulfoxide (DMSO), pyridine-N-oxide, and acetonetriphenyl were prepared and characterized by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy [ 42 ]. In [(CH 3 ) 2 CO] 3 XeO 3 each of the XeO 3 molecules is coordinated to three acetone molecules ( Figure 16 ).…”

“…In XeO 3 adducts, the xenon-ligand bonds may be described as predominantly electrostatic, (weakly covalent) interactions between the highly electrophilic σ-holes of the xenon atom and the electronegative ligand atom [ 42 ].…”