IR spectroscopy and density functional theory (B3LYP/6-31++G(d, p)) are used to study the competition between methanol and water molecules during the formation of (CH3(H)O∙∙∙H∙∙∙O(H)CH3)+, (CH3(H)O∙∙∙H∙∙∙OH2)+, and (H2O∙∙∙H∙∙∙OH2)+ ions with strong quasi-symmetrical H-bonds and their solvation in the CH3OH–H2O–HCl system. When water is added to a solution of HCl in methanol, H2O molecules substitute CH3OH molecules in (CH3(H)O∙∙∙H∙∙∙O(H)CH3)+ ions to form mixed disolvates. Conversely, when methanol is added to an aqueous solution of HCl, (H2O∙∙∙H∙∙∙OH2)+ ions are maintained and CH3OH molecules are involved in their solvation. Provided that the fractions of methanol and water are commensurate, the solutions contain simultaneously (CH3(H)O∙∙∙H∙∙∙OH2)+ and (H2O∙∙∙H∙∙∙OH2)+ ions. The ratio between their concentrations depends on the content of HCl in the system. It is shown that the energy of the hydrogen bond system per one dissociated HCl molecule is the main factor determining the structure of CH3OH–H2O–HCl solutions, in particular, the composition of proton disolvates.

中文翻译：

---

甲醇和水分子之间在 CH3OH – H2O – HCl 系统中形成和溶解离子的竞争

红外光谱和密度泛函理论（B3LYP / 6-31 ++ G (d, p)）用于研究甲醇和水分子在（CH3 (H) O ∙∙∙ H ∙∙∙ O 形成过程中的竞争） (H) CH3) +、(CH3 (H) O ∙∙∙ H ∙∙∙ OH2) + 和 (H2O ∙∙∙ H ∙∙∙ OH2) + 离子具有强准对称氢键及其在CH3OH – H2O – HCl 系统。当将水加入 HCl 的甲醇溶液中时，H2O 分子取代 (CH3 (H) O ∙∙∙ H ∙∙∙ O (H) CH3) + 离子中的 CH3OH 分子，形成混合溶剂化。相反，当甲醇加入到 HCl 的水溶液中时，(H2O ∙∙∙ H ∙∙∙ OH2) + 离子被保留下来，并且 CH3OH 分子参与了它们的溶剂化。如果甲醇和水的比例相称，则溶液同时含有 (CH3 (H) O ∙∙∙ H ∙∙∙ OH2) + 和 (H2O ∙∙∙ H ∙∙∙ OH2) + 离子。