Polarity of pure ionic liquids and at the phase boundary with inorganic solid catalysts

本文将借助微致变色探针和模型反应动力学研究无机固体酸（硅胶、硅酸铝、氧化铝）与离子液体（RTIL -室温离子液体）界面的极性和催化反应活性。最重要的目标是将多相催化的优点与离子液体的化学性质相结合，从而设计出新的反应介质。为了确定离子液体在界面处的局部极性，将使用紫外/可见光谱法测量离子液体颗粒悬浮液中的各种溶剂化变色染料。这些染料分别优先响应酸性（氢键提供能力，HBA）¿、碱性（氢键接受能力）ß和双极性/极化性¿*。单个参数¿，ß和¿*将使用多重相关分析进行评估。首先，必须讨论一个概念性问题，即如何对纯离子液体的单个参数¿，ß和¿*进行评估。研究了离子液体中阴离子的hba标度。这是项目第一部分的中心点。在第二部分的目的是离子液体的概念发展，吸附在固体酸颗粒表面，它应该显示没有RTIL性质的非吸附形式。因此，非对称取代咪唑、吡啶和四烷基铵盐将被使用，其中阴离子-固体表面相互作用的强度将被选择性地设置，以减少阳离子-阴离子相互作用。作为量化表面性质的模型反应，氢化物离子向碳离子的转移将被使用，其中反应的速率常数将被确定，并将根据最佳可用技术与极性参数相关联。

The polarity and catalytic reactivity at the interface of inorganic solid acids (silica gels, aluminosilicates, aluminium oxide) with ionic liquids (RTIL - room temperature ionic liquids) will be studied with the aid of soIvatochromic probes and with the kinetics of model reactions. The most important goal is the combination of the advantages of heterogeneous catalysis with the chemistry of ionic liquids, in order to design new reaction media.In order to determine the local polarities of ionic liquids at interfaces, various solvatochromic dyes will be measured in particle suspensions of ionic liquids using UV/visible spectroscopy. These dyes respond preferentially to the acidity (hydrogen bond donating ability, HBA) ¿, basicity (hydrogen bond acceptor ability) ß, and dipolarity/polarisability ¿* respectively. The individual parameters ¿, ß and ¿* will be evaluated using multiple correlation analysis. First the conceptual question must be discussed, on how the individual parameters ¿, ß and ¿* are to be evaluated for pure ionic liquids. It is intended to develop an HBA-scale for anions of ionic liquids. This is the central point of the first part of the project.In the second part the aim is the conceptual development of ionic liquids, adsorbed on solid acid particle surfaces, which should show no RTIL properties in the unadsorbed form. Thus non-symmetrically substituted imidazolium, pyridinium, and tetraalkylammonium salts will be used, where the strength of the anion-solid surface interaction will be set selectively, in order to reduce the cation-anion interactions. As a model reaction for the quantification of surface properties, the transfer of hydride ions to carbenium ions will be used, where the rate constants of the reaction will be determined, and will be correlated to the polarity parameters according to the best available technology.