The salts of chloronium ions R–Cl+–R (R = CH3 or CH2Cl): formation, thermal stability, and interaction with chloromethanes

Abstract

The interaction of CH₃Cl/CD₃Cl or CH₂Cl₂/CD₂Cl₂ with the carborane acid H(CHB₁₁Cl₁₁) (abbreviated as H{Cl₁₁}) generates the salts of CH₃–{Cl₁₁} and CH₂Cl–{Cl₁₁} and their deuterio analogs, respectively, which are analogs of the salts of asymmetric chloronium cations. Next, salts of chloronium cations CH₃–Cl⁺–CH₃, ClCH₂–Cl⁺–CH₂Cl, and ClCH₂–Cl⁺–CH₃ and their deuterio analogs were obtained from the above compounds. The asymmetric ClCH₂–Cl⁺–CH₃ cation was found to be unstable, and at ambient temperature, slowly disproportionated into symmetric cations (CH₃)₂Cl⁺ and (CH₂Cl)₂Cl⁺. At a high temperature (150 °C), disproportionation was completed within 5 minutes, and the resulting cations further decomposed into CH₃–{Cl₁₁} and CH₂Cl–{Cl₁₁}. The molecular fragment ClCH₂–(X) of the compounds (X = {Cl₁₁}, –Cl⁺–CH₂Cl, or –Cl⁺–CH₃) is involved in exchange reactions with CH₂Cl₂ and CHCl₃, converting into CH₃–(X) with the formation of chloroform and CCl₄, respectively.