Untersuchungen zur Lewis‐Acidität fluorierter Sulfonium‐Ionen

Abstract

NMR‐Untersuchungen zeigen, daß Sulfoniumsalze [(CF3)nSF3−n]+ AsF6− (1−3, n = 0−2) CH3CN addieren unter Bildung ψ‐pentakoordinierter Sulfuranoniumionen [(CF3)nSF3−n · NCCH3]+ mit axialständigem Donor. NSF3 (4,) bildet in Lösung die analogen Salze [(CF3)n SF3−n · NSF3]+ AsF6− (1b‐3b,) mit schwächerer Donor‐Akzeptor‐Wechselwirkung. Bei Umsetzungen mit NSF2NMe2 (5,), wird die Stufe der Primärprodukte sehr schnell durchlaufen; unter Fluoridwanderung kommt es mit 1, und 2, zur Bildung von Persulfuranonium‐Ionen ([(CH3)2NSF3NSF2]+ (6,) bzw. [(CH3)2NSF3NSFCF3]+ (7,)), während aus der Umsetzung mit 3, nur Zersetzungsprodukte (Me2NSF2+, CF3SSCF3, CF4) erhalten wurden.

Lewis Superacids: Classifications, Candidates, and Applications

“…Although chalcogen(II/IV) cations and dications have been described, their Lewis acidity is not expected to be very high . Even the perfluorinated sulfonium ion (CF 3 ) 2 SF + is stable towards AsF 6 − . S VI sulfoxonium cations where prepared recently by fluorination of a S IV precursor and fluoride abstraction in substantial amounts (>500 mg, Figure c) .…”

“…[190] Even the perfluorinated sulfonium ion (CF 3 ) 2 SF + is stable towards AsF 6 À . [191] S VI sulfoxonium cations where prepared recently by fluorination of aS IV precursor and fluoridea bstraction in substantial amounts( > 500 mg, Figure 7c). [192] The Lewis acidityo nt he GB scale clearlye xceeded that of B(C 6 F 5 ) 3 .T he FIA was calculated (non-isodesmic) as 604 kJ mol À1 in the gas phase and even higher (635 kJ mol À1 )i n solution (COSMO-RS).…”

Heterocations in Superacid Systems

“…223 All three ions react with acetonitrile to form y-pentacoordinated ions [Eq. 223 All three ions react with acetonitrile to form y-pentacoordinated ions [Eq.…”

Thiazyl Trifluoride (NSF3) Adducts and Imidodifluorosulfate (F2OSN-) Derivatives of Hg(OTeF5)2

“…6,12 Other NSF 3 adducts with main-group atom centers include [(CF 3 ) n SF 3−n NSF 3 ][AsF 6 ] (n = 0−2), 13 6 ], 15 with the latter three adduct-cations and F 3 S NAsF 5 , 3 having been characterized by single-crystal X-ray diffraction. The reactions of NSF 3 with Lewis acidic metal centers have also been studied and provide a series of transition metal adducts [M(NSF 3 ) 4 ][AsF 6 ] 2 (M = Mn, Fe, Co, Ni, Cu, Zn), 16−18 [CpFe(CO) 2 NSF 3 ][AsF 6 ], 19 [M(CO) 5 19,20 and [Ag(NSF 3 ) n ][AsF 6 ] (n = 1, 2), 16 which have been structurally characterized by physical methods such as IR and/or Raman spectroscopy, NMR spectroscopy, and mass spectrometry.…”

“…The Lewis basicity of NSF 3 is illustrated by its reactions with the Lewis acids AsF 5 , SbF 5 , and BF 3 , which yield the Lewis acid–base adducts F 3 SNAsF 5 , , F 3 SNSbF 5 , and F 3 SNBF 3 . , Other NSF 3 adducts with main-group atom centers include [(CF 3 ) n SF 3–n NSF 3 ]­[AsF 6 ] ( n = 0–2), [F 3 S­(NSF 3 ) 2 ]­[AsF 6 ], [F 4 SNXeNSF 3 ]­[AsF 6 ], and [F 3 SNXeF]­[AsF 6 ], with the latter three adduct-cations and F 3 SNAsF 5 , having been characterized by single-crystal X-ray diffraction. The reactions of NSF 3 with Lewis acidic metal centers have also been studied and provide a series of transition metal adducts [M­(NSF 3 ) 4 ]­[AsF 6 ] 2 (M = Mn, Fe, Co, Ni, Cu, Zn), − [CpFe­(CO) 2 ­NSF 3 ]­[AsF 6 ], [M­(CO) 5 NSF 3 ]­[AsF 6 ] (M = Mn, Re), , and [Ag­(NSF 3 ) n ]­[AsF 6 ] ( n = 1, 2), which have been structurally characterized by physical methods such as IR and/or Raman spectroscopy, NMR spectroscopy, and mass spectrometry.…”