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

借助于变色探针和模型反应动力学，研究了无机固体酸(硅胶、硅酸铝、氧化铝)与离子液体(室温离子液体)界面上的极性和催化活性。最重要的目标是将多相催化的优点与离子液体的化学相结合，以设计新的反应介质。为了确定离子液体在界面上的局部极性，我们将利用紫外可见光谱测量离子液体颗粒悬浮液中的各种溶致变色染料。这些染料分别优先响应酸性(氢键贡献能力，HBA)、碱性(氢键接受能力)和偶极/极化率*。各个参数？、？和？*将使用多重相关分析进行评估。首先必须讨论概念问题，即如何评估纯离子液体的各个参数？、？和？*。它的目的是开发一种离子液体阴离子的HBA标尺。这是项目第一部分的中心点。在第二部分中，目标是离子液体的概念发展，吸附在固体酸性粒子表面，它不应该在未吸附的形式表现出RTIL性质。因此，将使用非对称取代的咪唑、吡啶和四烷基铵盐，其中将选择性地设置阴离子-固体表面相互作用的强度，以减少阳离子-阴离子相互作用。作为表面性质量化的模型反应，将使用氢化物离子向卡宾离子的转移，其中将确定反应的速率常数，并将根据最佳可用技术将其与极性参数相关联。

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.