Minkwitz R, Reinemann S, Seelbinder R, Konikowski D, Hartl H, Brüdgam I, Hegge J, Hoge B, Sheehy J A, Christe K O
Anorganische Chemie, Fachbereich Chemie der Universität Dortmund, Germany.
Inorg Chem. 2001 Aug 13;40(17):4404-8. doi: 10.1021/ic010239w.
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.
在超酸性HF/SbF₅体系中，三氟甲基甲醚于-78℃形成新的叔氧鎓盐[(CH₃)₂OCF₃]⁺[Sb₂F₁₁]⁻，通过拉曼光谱、多核核磁共振光谱及其晶体结构对其进行了表征。在-30至-10℃的HF溶液中，用CH₃F和SbF₅对CH₃OCF₃进行甲基化反应也可得到相同的氧鎓盐。用体积更大且电负性更强的三氟甲基取代三甲氧鎓阳离子中的一个甲基，会使剩余的O-CH₃键长增加0.037(1) Å，C-O-C键角之和增加约4.5度。在-30℃的HF/SbF₅溶液中，用CH₃F对CH₃OCF(CF₃)₂进行甲基化反应生成[(CH₃)₂OCF(CF₃)₂]⁺[Sb₂F₁₁]⁻。通过在B3LYP/6-311++G(2d,2p)和MP2/6-311++G(2d,p)水平上的理论研究，证实了所观察到的结构以及振动光谱和核磁共振光谱。
