Ennobling an Old Molecule: Thiazyl Trifluoride (N≡SF₃), a Versatile Synthon for Xe–N Bond Formation

Abstract

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≡SF(3). The adduct-cation, F(3)S≡NXeF(+), has provided the entry point to a significant chemistry through HF solvolysis of the coordinated N≡SF(3) ligand and HF-catalyzed and solid-state rearrangements of F(3)S≡NXeF(+). The HF solvolyses of [F(3)S≡NXeF][AsF(6)] in anhydrous HF (aHF) and aHF/BrF(5) solutions yield the F(4)S═NXe(+) cation, which likely arises from an HF-catalyzed mechanism. The F(4)S═NXe(+) cation, in turn, undergoes HF displacement to form F(4)S═NH(2)(+) and XeF(2), as well as HF addition to the S═N bond to form F(5)SN(H)Xe(+). Both cations undergo further solvolyses in aHF to form the F(5)SNH(3)(+) cation. The F(4)S═NXe(+) and F(4)S═NH(2)(+) 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 F(4)S═N- group and significantly extend the chemistry of this ligand. The solid-state rearrangement of [F(3)S≡NXeF][AsF(6)] at 22 °C has yielded [F(4)S═NXe][AsF(6)], which was characterized by Raman spectroscopy, providing the first examples of xenon bonded to an imido nitrogen and of the F(4)S═N- group bonded to a noble-gas element. The rearrangement of [F(3)S≡NXeF][AsF(6)] in a N≡SF(3) solution at 0 °C also yielded [F(4)S═NXe−N≡SF(3)][AsF(6)], which represents a rare example of a N−Xe−N linkage and the first to be characterized by X-ray crystallography. Solvolysis of N≡SF(3) in aHF was previously shown to give the primary amine F(5)SNH(2), whereas solvolysis in the superacid medium, AsF(5)/aHF, results in amine protonation to give [F(5)SNH(3)][AsF(6)]. Complete structural characterizations were not available for either species. Isolation of F(5)SNH(2)·nHF from the reaction of N≡SF(3) with HF has provided a structural characterization of F(5)SNH(2) by Raman spectroscopy. Crystal growth by sublimation of F(5)SNH(2)·nHF at -30 to -40 °C has resulted in the X-ray crystal structure of F(5)SNH(2)·2[F(5)SNH(3)][HF(2)]·4HF and structural characterizations of F(5)SNH(2) and F(5)SNH(3)(+). The redox decomposition of [F(4)S═NXe−N≡SF(3)][AsF(6)] in N≡SF(3) at 0 °C generated Xe, cis-N(2)F(2), and [F(3)S(N≡SF(3))(2)][AsF(6)].

Gas-Phase Ion Chemistry of the Noble Gases: Recent Advances and Future Perspectives

“…The H 3 C-CN-XeF + adduct observed from the addition of XeF + to CH 3 CN 223 is reminiscent of a large group of Xe-N cations, observed in the solid or liquid phase, that arise from the interaction of XeF + with Lewis nitrogen bases such as hydrogen cyanide, alkylnitriles, pentafluorobenzenenitrile, perfluoroalkylnitriles, perfluoropyridines and s-trifluoro-triazine. 256,257 In these complexes, the xenon-nitrogen interaction is relatively tight and the observed Xe-N distances range around 2.2-2.3 Å. A second group of condensed-phase Xe-N cations includes (FO 2 S) 2 NXe + , 258,259 F 5 SN(H)Xe + , 257,260 F 5 TeN(H)Xe + , 261 and F 4 S=NXe + .…”

“…256,257 In these complexes, the xenon-nitrogen interaction is relatively tight and the observed Xe-N distances range around 2.2-2.3 Å. A second group of condensed-phase Xe-N cations includes (FO 2 S) 2 NXe + , 258,259 F 5 SN(H)Xe + , 257,260 F 5 TeN(H)Xe + , 261 and F 4 S=NXe + . 257,262,263 These species can be regarded as a Xe atom that interacts with the nitrenium ions (FO 2 S) 2 N + , F 5 SN(H) + , F 5 TeN(H) + and F 4 S=N + and are invariably characterized by covalent Xe-N bonds, with short distances of nearly 2.0-2.1 Å.…”

“…A second group of condensed-phase Xe-N cations includes (FO 2 S) 2 NXe + , 258,259 F 5 SN(H)Xe + , 257,260 F 5 TeN(H)Xe + , 261 and F 4 S=NXe + . 257,262,263 These species can be regarded as a Xe atom that interacts with the nitrenium ions (FO 2 S) 2 N + , F 5 SN(H) + , F 5 TeN(H) + and F 4 S=N + and are invariably characterized by covalent Xe-N bonds, with short distances of nearly 2.0-2.1 Å. Very recently, 231 the xenon-difluoronitrenium cation F 2 N-Xe + was obtained in the gas phase from Reaction (2) F 2 N-FH + + Xe ® F 2 N-Xe + + HF (2) observed by IT-MS. Based on theoretical results, the ionic product was unambiguously assigned as F 2 N-Xe + .…”

Noble‐Gas Compounds

“…Xenon(II) also forms bonds to inorganic nitrogen bases, including F 3 S À À À À À À NXeF þ AsF À 6 , F 3 S À À À À À À NXeOTeF þ 5 AsF À 6 , and F 3 S À À À À À À NXeOSeF þ 5 AsF À 6 , which are formed by reaction of the corresponding xenon cation, XeL þ , with liquid F 3 S À À À À À À N at -20 C or in HF solvent (26). Reaction of F 3 S À À À À À À NXeF þ AsF À 6 in HF leads to F 4 S À À À À À À NXe þ AsF À 6 and F 5 SN(H)Xe þ .…”

Theoretical predictions of the nitrogen heterocyclic compounds with metal and noble gas (metal = Cu, Ag, Au)

“…These new findings began to change people's perception of the chemical bonding ability of noble gases. Subsequently, many experimental scientists contributed to new Ng compounds, and with the rapid development of precision computation technology, a large number of thermodynamically and kinetically stable Ng compounds have been theoretically predicted including HNgY (Ng = Ar, Kr, Xe, Y = electronegative chemical groups), HXeCCH (C nv ), HXeCC (C nv ), and HXeCCXeH (D 2h ), and B n Ng n (n‐2)+ and B 3 N 3 NgR 6. And the most recently detected Ng compound is Na 2 He, a stable compound of helium and sodium, which was first predicted using the ab initio evolutionary algorithm universal structure prediction: evolutionary xtallography and subsequently was synthesized at high pressure in a diamond anvil cell by Xiao Dong and coworkers …”