Abstract:

The copper coordination compound [C₁₀H₉N]₂CuBr₂ was prepared by the reaction of 4-methylchinolin with copper bromide in ethanol solution. The compound was characterized with FTIR, EA, ICP-AES and XRD, and its catalytic performance in oxidative carbonylation of ethanol was investigated. The density functional theory (DFT) calculations were performed to analyze its structure, natural atomic charges and frontier orbital energy levels. The introduction of ligand could improve catalytic activity to prepare diethyl carbonate. The per pass conversion of ethanol could reach 21.5% under the reaction conditions of temperature 373 K, pressure 3.5 MPa, time 4 h and mass concentration of catalyst in ethanol 0.075 g·ml^-1. Reaction mechanism study showed that the compound had moderate stability, which benefited insertion of CO (the rate-controlling step) and formation of intermediate. Therefore, reaction activity was enhanced.

Key words: compound, density functional theory, oxidative carbonylation, catalyst, conversion

摘要：

以CuBr₂和4-甲基喹啉为原料, 在乙醇溶剂中制备了含溴铜(Ⅱ)配合物。通过FTIR、EA、XRD和ICP-AES表征, 初步确定了配合物分子结构为[C₁₀H₉N]₂CuBr₂;采用密度泛函理论计算对其结构、自然原子电荷和前线轨道进行分析, 进一步确定分子结构的可靠性, 并将该配合物应用于乙醇氧化羰化合成碳酸二乙酯催化反应中。结果表明, 在催化剂浓度为0.075 g·ml^-1, 反应温度为100℃, 反应压力为3.5 MPa, 反应时间为4 h的条件下, 乙醇的转化率达到21.5%。通过探讨反应机理, 认为该配合物催化剂稳定性适中, 有利于主反应控制步骤CO的插入反应, 有助于中间体的形成, 从而使催化活性得到提高。

关键词: 配合物, 密度泛函理论, 氧化羰化, 催化剂, 转化率