NER: Immobilized Calixarenes as Nanomaterials for Selective Catalysis and Molecular Recognition

该提案是对NSF 03-043，NER类纳米科学与工程倡议的响应。这项研究致力于设计和合成一类用于对映体选择性吸附和催化的新型单位材料，这种材料可以在纳米尺度上进行定制，具有前所未有的细节水平。该材料由接枝在二氧化硅表面的茂金属芳烃结构组成。这些接枝物种最近被证明能够从气相和液体中吸附小的有机分子，并作为高活性和选择性的环氧化催化剂。这些特性包括对映体特异性的分子识别。该方法利用杯芳烃化学的最新进展进行上缘官能化，包括定位手性官能团来定义不对称口袋。在催化方面，最近在环氧化反应中取得的成功将通过将手性基团放置在催化活性中心的负键接触(0.24 nm)附近和内部来扩展，例如钛-杯芳烃结构中的那些。在项目过程中合成的材料应在手性分子的合成和分离以及制药、特种单体(聚合物和液晶显示器)和农用化学品部门的工业应用中得到广泛应用。这些研究活动广泛影响了对新兴纳米技术领域科学家的培训，特别强调具有特定纳米级连通性和空间安排的材料的合成和结构表征。研究生和本科生将在多学科基础设施内接受纳米材料设计和合成方面的培训，其中包括杯芳烃和材料的合成化学、其光谱表征以及评估接枝的茂金属芳烃材料的吸附和催化功能的实验仪器设计方面的专业知识。研究活动包括一个本科生实验室部分，积极争取妇女和少数群体参与。

This proposal was received in response to Nanoscience and Engineering initiative, NSF 03-043, category NER. This research addresses the design and synthesis of a new class of single-site materials for enantioselective adsorption and catalysis, which can be tailored on the nanoscale with an unprecedented level of detail. The materials consist of metallocalixarene structures grafted on the surface of silica. These grafted species have been recently shown to adsorb small organic molecules from vapor and liquid phases and to act as highly active and selective epoxidation catalysts. These properties include enantiospecific molecular recognition. The approach exploits recent advances in calixarene chemistry for upper rim functionalization, including the positioning of chiral functional groups to define an asymmetric pocket. For catalysis, recent success in epoxidation reactions will be extended by placing chiral groups in the immediate vicinity of and within dative bond contact (0.24 nm) of catalytically active centers, such as those in titano-calixarene structures. The materials synthesized in the course of the project should find broad use in the synthesis and separation of chiral molecules and in industrial applications within pharmaceutical, specialty monomer (for polymers and liquid crystal displays), and agrochemical sectors. These research activities broadly impact the training of scientists in emerging nanotechnology areas, with specific emphasis on the synthesis and structural characterization of materials with specific nanoscale connectivity and spatial arrangements. Graduate and undergraduate students will be trained in the design and synthesis of nanomaterials within a multi-disciplinary infrastructure, which includes expertise in synthetic chemistry of calixarenes and materials, their spectroscopic characterization, and the design of experimental apparatus for the assessment of adsorption and catalytic functions of grafted metallocalixarene materials. Research activities include an undergraduate laboratory component in which participation by women and minorities is actively sought.