基于酸性光谱定量分析为核心的类离子液体构效与催化机制研究

The quantitative analysis and directional control of acidity are important scientific issues in the design and application of ionic liquid analogues, known as a new type of green liquid catalyst. Single characterization methods of acidity are limited, and fail to make a comprehensive quantitatively analysis. The project proposes to establish a new method for the determination of acidic amount of ionic liquid analogues by combining the real-time monitoring function of in-situ infrared spectrometer with the principle of titration analysis. On this basis, the optimum combinatorial method to analyze quantitatively the acidity of ionic liquid analogues based on in-situ infrared titration, phosphorus NMR probe, and NMR analysis methods is constructed. The new combinatorial method can qualitative distinguish each acidic species, and can also make a quantitative analysis on their acidic strength and acidic amount compared with the traditional characterization method. On the basis of quantitative spectrometric analysis of acidity as the core, the composition structure of ionic liquid analogues was analyzed to study the inherent law between composition structure and acid regulation. Meanwhile, the intrinsic relationship between acid regulation and catalytic performance is studied in combination with specific model reaction to establish the ternary structure-property relationship between the structure, acidity, and catalytic performance, which reveals the law of acid regulation and the catalytic mechanism of acidic species from the molecular level. This study will provide guidance and suggestion for the design and development of ionic liquid analogues, acid regulation and their application in green catalysis.

对绿色液态催化剂的酸性进行定量分析与定向调控是类离子液体结构设计与催化应用面临的重要科学问题。单一的表征方法均存在局限性，无法对其酸性做出全方位定量分析。本项目提出利用在线红外的实时监测功能并结合滴定分析原理建立类离子液体酸量测定的在线红外滴定新方法。在此基础上构建以在线红外滴定法、磷核磁分子探针法、核磁分析法为基础的优化组合方法来全方位定量分析酸性的新策略。与传统表征方法相比，所构建的新方法能定性区分各酸性物种，还能定量分析酸强度和酸量。以酸性光谱定量分析为主线，开展类离子液体的组成结构分析，研究组成结构与酸性调控的内在规律，结合特定的模型反应，研究酸性调控与催化性能的内在联系，以建立组成结构-酸性-催化性能三元构效关系，从分子层次上揭示酸性的调变规律，明确酸性物种的催化机制。本研究可为类离子液体的设计开发、酸性调控及绿色催化应用提供指导建议。

本项目通过红外、核磁、紫外等光谱表征方法，探索了关键合成因素对含Lewis酸类离子液体结构的影响。结果表明配体结构与含量影响着Al2Cl6二聚体的不对称裂分程度，是调控类离子液体结构的两个关键因素。通过筛选空间结构不同的碱性化合物作为指示剂，构建出了具有实时监测功能和良好普适性的针对总酸量测定的在线红外滴定新方法，并研究了类离子液体结构与总酸量的之间的构效关系。双齿配位结构类离子液体的活性指数要高于单齿配位结构类离子液体的活性指数。通过选取空间结构不同的含磷化合物作为磷核磁分析的分子探针，构建出了适用于类离子液体酸强度分析的定量方法。类离子液体中含有两种酸性铝物种和两种无酸性的铝物种，且阳离子铝物种的酸强度要略高于阴离子酸性铝物种。通过对各酸性物种的Al核磁峰面积进行积分归一化处理，定量分析出了各酸性铝物种的酸量。类离子液体中阳离子铝物种的酸量要略高于阴离子酸性铝物种的酸量。以异丁烷烷基化和正戊烷异构化为模型反应，将酸性全方位定量分析方法应用到类离子液体催化机制中，探讨了类离子液体的组成结构-酸性-催化性能之间的三元构效关系。项目资助发表SCI收录论文3篇，培养硕士研究生2名。项目投入经费25万元，支出13.62万元，各项支出基本与预算相符。剩余经费11.38万元计划用于本项目研究后续支出。