Elucidating the Organic-OMS Interface and Its Implications for Solid Enantioselective Catalysts

提议标题：阐明有机-OMS界面及其对固体对映体选择性催化剂的影响建议编号：CTS-0624813主要研究员：Daniel Shantz研究所：德克萨斯工程实验站分析(决策的基本原理)：有序介孔二氧化硅(OMS)有机杂化化合物作为潜在的均相催化剂的多相类似物引起了极大的兴趣。该项目将通过使用固体核磁共振波谱对无机-有机界面进行严格的描述，以确定：(1)附着在OMS表面的基团的旋转迁移率；(2)有机基团相对于OMS表面的局部结构和构象。当与催化测试相结合时，这项工作将展示纳米尺度的结构和动力学如何影响反应活性，从而导致杂化材料的新设计范式及其在催化中的使用。这项工作将研究化学上简单的官能团，如表面连接的烷基胺基团，表面捆绑的均相催化剂，如席夫碱(如Al-Salen)，以及对映体选择性有机催化感兴趣的短肽。这项工作的学术价值有四个方面。对于有序介孔二氧化硅表面共价连接的有机基团的局部结构(第一)和动力学(第二)以及它们如何受到表面疏水性、负载和溶剂化的影响的分子描述是缺乏的。这种类型的信息对于设计催化相关材料中的有机-无机界面是必不可少的。第三，反应性是如何被这些局部结构现象改变的还不清楚。第四，这些知识将为合理设计有机-无机界面，特别是有序介孔二氧化硅上的有机层催化提供新的范式。这项工作的更广泛的影响也是四方面的。首先，将局部结构和动力学与功能联系起来的能力将导致有机-无机杂化材料的更有效设计。这里提出的工作特别涉及有机催化和对映体选择性反应，但也将一般与催化以及包括分子识别和分离在内的影响领域的研究人员相关。其次，设计对映体选择性固体催化剂的能力，特别是那些没有金属中心的催化剂，将对精细化工和制药行业产生影响。第三，课程开发将向化学工程师介绍固态核磁共振方法。第四，这项研究将通过德克萨斯农工大学校园现有的项目吸引本科生参与，这项工作的结果也将通过K-12项目传播。

AbstractProposal Title: Elucidating the Organic-OMS Interface and Its Implications for Solid Enantioselective Catalysts Proposal Number: CTS-0624813Principal Investigator: Daniel ShantzInstitution: Texas Engineering Experiment StationAnalysis (rationale for decision):Ordered Mesoporous Silica (OMS) organic hybrids have attracted great interest as potential heterogeneous analogues of homogeneous catalysts. This project will lead to a rigorous description of the inorganic-organic interface by using solid-state nuclear magnetic resonance (NMR) spectroscopy to determine: (1) the rotational mobility of groups attached to OMS surfaces, and (2) the local structure and conformation of the organic group with respect to the OMS surface. When coupled with catalytic testing, this work will show how structure and dynamics at the nanometer length scale influence reactivity, leading to new design paradigms for hybrid materials and their use in catalysis. This work will investigate chemically simple functional groups such as alkylamine groups attached to surfaces, surface tethered homogeneous catalysts such as Schiff bases (e.g. Al-salen), and short peptides which are of interest for enantioselective organocatalysis. The intellectual merit of this work is fourfold. A molecular description of the local structure (first) and dynamics (second) of organic groups covalently attached to ordered mesoporous silica surfaces and how they are affected by surface hydrophobicity, loading, and solvation is lacking. This type of information is essential to designing organic-inorganic interfaces in materials that are catalytically relevant. Third, how reactivity is modified by these local structural phenomena is not understood. Fourth, this knowledge will provide new paradigms for rationally designing organic-inorganic interfaces in general, and organic layers on ordered mesoporous silica for catalysis in particular.The broader impact of this work is also fourfold. First, the ability to relate local structure and dynamics to function will lead to more efficient design of organic-inorganic hybrids. The work proposed here relates specifically to organocatalysis and enantioselective reactions but will also be generally relevant to researchers in catalysis as well as impact fields including molecular recognition and separations. Second, the ability to design enantioselective solid catalysts, particularly those without a metal center, will have implications for both the fine chemicals and pharmaceutical industries. Third, the curriculum development will introduce Chemical Engineers to solid-state NMR methods. Fourth, this research will involve undergraduate students through existing programs on the Texas A&M campus and the results of this work will also be disseminated through a K-12 program.