Pseudo Halide Chemistry in Ionic Liquids with Decomposable Anions

Several pseudohalide containing ionic liquids with quarternary ammonium counter cations of the general formula R₃MeN]X R = ethyl ( 1X ), n‐butyl ( 2X ) with X^– = CN^–, N₃^–, OCN^–, and SCN^–] were synthesized by decomposition of the corresponding trialkylammonium methylcarbonate in the reaction with Me₃Si–X. We also treated 2CN with OP(OMe)₃, yielding nBu₃MeN]O₂P(OMe)₂] and acetonitrile (Me‐CN). The double salt nBu₃MeN]₂{B(OMe)₃(CN)](CN)} was obtained from the reaction of 2CN with B(OMe)₃, featuring the formation of the monocyanotrimethoxyborate anion, B(OMe)₃(CN)]^–, co‐crystallized with nBu₃MeN]CN. nBu₃MeN]₂{B(OMe)₃(CN)](CN)} was fully characterized including structure elucidation.