Ennobling an Old Molecule: Thiazyl Trifluoride (NSF3), a Versatile Synthon for Xe-N Bond Formation

The fields of sulfur-nitrogen-fluorine chemistry and noble-gas chemistry have been significantly extended by the syntheses and characterizations of four new Xe-N-bonded cations derived from N SF3. The adduct-cation, F3S NXeF+, has provided the entry point to a significant chemistry through HF solvolysis of the coordinated N SF3 ligand and HF-catalyzed and solid-state rearrangements of F3S NXeF+. The HF solvolyses of [F3S NXeF][AsF6] in anhydrous HF (aHF), and aHF/BrF5 solutions yield the F4S=NXe+ cation, which likely arises from an HF-catalyzed mechanism. The F4S=NXe+ cation, in turn, undergoes I-IF displacement to form F4S=NH2+ and XeF2, as well as HF addition to the S=N bond to form F5SN(H)Xe+. Both cations undergo further solvolyses in aHF to form the F5SNH3+ cation. The F4S=NXe+ and F4S=NH2+ cations were characterized by NMR spectroscopy and single-crystal X-ray diffraction and exhibit high barriers to rotation about their S=N double bonds. They are the first cations known to contain the F4S=N-group and significantly extend the chemistry of this ligand. The solid-state rearrangement of [F3S NXeF][AsF6] at 22 degrees C has yielded [F4S=NXe][AsF6], which was characterized by Raman spectroscopy, providing the first examples of xenon bonded to an imido nitrogen and of the F4S=N- group bonded to a noble-gas element. The rearrangement of [F3S NXeF][AsF6] in a N SF3 solution at 0 degrees C also yielded [F4S=NXe-N SF3][AsF6], which represents a rare example of a N-Xe-N linkage and the first to be characterized by X-ray crystallography. Solvolysis of N SF3 in aHF was previously shown to give the primary amine F5SNH2, whereas solvolysis in the superacid medium, AsF5/aHF, results in amine protonation to give [F5SNH3][AsF6]. Complete structural characterizations were not available for either species. Isolation of F5SNH2 center dot nHF from the reaction of N SF3 with HF has provided a structural characterization of F5SNH2 by Raman spectroscopy. Crystal growth by sublimation of F5SNH2 center dot nHF at -30 to -40 degrees C has resulted in the X-ray crystal structure of F5SNH2 center dot 2[F5SNH3][HF2]center dot 4HF and structural characterizations of F5SNH2 and F5SNH3+. The redox decomposition of [F4S=NXe-N SF3][AsF6] in N SF3 at 0 degrees C generated Xe, cis-N2F2, and [F3S(Na SF3)(2)][AsF6].