杂多酸盐类超分子催化剂的合成及其在催化氧化反应中的应用

The cyclodextrin(CD) derivatives containing amino groups and carboxyl groups were readily obtained through the chemical modification to the outer rim of CDs, and then further structurally characterized. The novel supramolecular compounds have been fabricated at a molecular level by covalent interaction or electrostatic interaction between new synthesized cyclodextrin derivatives and polyoxometalate(POM)-based catalysts in aqueous solution. The new POM-based supramolecular catalysts were spectroscopically and structurally characterized by a wide range of analytical methods. Furthermore, in order to our better understanding of self-assembly mechanism, the influences of the various synthetic parameters (pH value, temperature, types of polyoxometalates and molar ratio, etc) on assembly process also will be investigated in detail. Our aim is to provide structure-tunable synthesis of supramolecular assembly of CDs ann POMs for the first time. The novel supramolecular catalysts based on POMs and CDs were applied on hydrogen peroxide-based catalytic oxidation of alcohols in an aqueous/organic two phase system, which act as a chemical nanoreactor in aqueous solution with the excellent combination of molecular recognition and phase-transfer properties. The organic substrates thus can be selectively and effectively transferred to the aqueous phase,and next will be inserted into the cyclodextrin cavities of supramolecular catalysts to form inclusion complexes. As a consequence, the presence of supramolecular compounds can improve catalytic reaction rate, meanwhile the resulting restrictions in guest molecular motions could thus be used to isolate and indentify of catalytic intermediates. Based on kinetic, spectroscopic studies together with computational method (DFT), all the present investigation shed new light on the catalytic mechanism involved in POM-assisted alcohol oxidation. In short, this innovative project not only bring forward new experimental principles for POM-based catalysts in industrial process, but it also open up the new field of supramolecular catalysis.

对环糊精外缘基团进行的化学修饰，合成并表征含有羧基、氨基等修饰基团的环糊精衍生物。通过化学键合或静电作用将其与杂多酸盐进行组装，在分子水平上构筑新颖的杂多酸盐类超分子催化剂。对新合成的超分子复合物进行一系列结构和谱学表征，并探讨其组装机理，研究在水溶液中各种反应因素(pH值、温度、杂多酸盐类型、反应物摩尔比等)对组装过程的影响，以实现超分子复合物的结构可控合成。随后将超分子催化剂应用于双液相醇氧化反应中，利用超分子纳米反应器的相转移性和分子识别性能，选择性地将有机底物从有机相转移到水相中组装在超分子催化剂上的环糊精的空腔内，从而提高催化反应速率，同时可以限制底物在水相中的移动，增加了分离活性中间体的可能。最后通过反应动力学及光谱学研究结果，并结合DFT理论计算，深入阐述催化氧化机理。本项目的创新性研究，为多酸催化剂的工业化应用提供可靠的实验依据，并成功拓展超分子催化领域的研究内容。

本项目通过化学键合和氢键作用将beta-环糊精与Keggin杂多酸盐HSiW12O40进行自组装，在分子水平上构筑新颖的三维杂多酸盐类超分子催化剂{3CD@SiW12}。对新合成的超分子复合物进行一系列结构和谱学表征，并探讨其组装机理，研究在水溶液中各种反应因素(pH值、温度、杂多酸盐类型、反应物摩尔比等)对组装过程的影响，以实现超分子复合物的结构可控合成。随后将超分子催化剂应用于双液相醇氧化反应中，利用超分子纳米反应器的相转移性和分子识别性能，选择性地将有机底物从有机相转移到水相中组装在超分子催化剂上的环糊精的空腔内，从而提高催化反应速率，同时可以限制底物在水相中的移动，增加了分离活性中间体的可能。最后通过光谱学研究结果，并结合DFT理论计算，深入阐述催化氧化机理。本项目的创新性研究，为多酸催化剂的工业化应用提供可靠的实验依据，并成功拓展超分子催化领域的研究内容。..根据项目计划书，各项目任务现已完成。项目执行期间取得了较好的研究成果，共计发表SCI论文9篇，累计影响因子约40，授权专利5项。项目执行期间，参加国际会议1次，5人次参加国内学术会议5次。培养硕士4名。已超额完成项目计划书中的研究目标。