Synthesis and characterization of the first examples of perfluoroalkyl-substituted trialkyloxonium salts, [(CH3)2OCF3]+[Sb2F11]- and [(CH3)2OCF(CF3)2]+[Sb2F11]-

R Minkwitz; S Reinemann; R Seelbinder; D Konikowski; H Hartl; I Brüdgam; J Hegge; B Hoge; J A Sheehy; K O Christe

doi:10.1021/ic010239w

Synthesis and characterization of the first examples of perfluoroalkyl-substituted trialkyloxonium salts, [(CH3)2OCF3]+[Sb2F11]- and [(CH3)2OCF(CF3)2]+[Sb2F11]-

Inorg Chem. 2001 Aug 13;40(17):4404-8. doi: 10.1021/ic010239w.

Authors

R Minkwitz¹, S Reinemann, R Seelbinder, D Konikowski, H Hartl, I Brüdgam, J Hegge, B Hoge, J A Sheehy, K O Christe

Affiliation

¹ Anorganische Chemie, Fachbereich Chemie der Universität Dortmund, Germany.

PMID: 11487348
DOI: 10.1021/ic010239w

Abstract

In the superacidic HF/SbF(5) system, methyl trifluoromethyl ether forms at -78 degrees C the new tertiary oxonium salt [(CH(3))(2)OCF(3)](+)[Sb(2)F(11)](-), which was characterized by Raman and multinuclear NMR spectroscopy and its crystal structure. The same oxonium salt was also obtained by methylation of CH(3)OCF(3) with CH(3)F and SbF(5) in HF solution at -30 to -10 degrees C. Replacement of one methyl group in the trimethyloxonium cation by the bulkier and more electronegative trifluoromethyl group increases the remaining O-CH(3) bond lengths by 0.037(1) A and the sum of the C-O-C bond angles by about 4.5 degrees. Methylation of CH(3)OCF(CF(3))(2) with CH(3)F in HF/SbF(5) solution at -30 degrees C produces [(CH(3))(2)OCF(CF(3))(2)](+)[Sb(2)F(11)](-). The observed structure and vibrational and NMR spectra were confirmed by theoretical studies at the B3LYP/6-311++G(2d,2p) and the MP2/6-311++G(2d,p) levels.