Cavitands and Self-Assembled Capsules as Supramolecular Reagents and Organo-Catalysts

几十年来，化学家们一直在从大自然中学习如何利用分子的内在属性来“自组装”成复杂的阵列，这些阵列具有完全独立于原始成分的新属性。杜兰大学的布鲁斯·吉布教授的这项研究项目利用碗状分子在组装过程中形成新的化学反应器。虽然类似于人们熟悉的试管，但这些化学反应器非常小。就像大自然的催化剂--酶一样，这些反应堆能够一次捕获一个分子，带来新颖和选择性的化学变化。此外，该研究计划旨在提高我们对使用极端温和的条件(例如，室温水)进行化学转化的理解。这项研究对社会很重要，因为它解决了国家在可持续发展方面的需求。使用室温水有助于降低生产化学品的能源成本，并避免与使用有机溶剂相关的环境问题。这项研究的更广泛影响包括教育和培训研究生和本科生，使其成为化学科学的下一代生产成员和领导者，以及旨在促进当地社区化学和扩大科学和工程领域参与的外联活动。超分子化学的最新技术现在已经达到了一个点，即(超)分子容器的建造相对容易。在此基础上，这项研究计划的一个重要目标是考虑如何设计纳米空间内的静电势场，以及在这样做的过程中，如何可能控制纳米空间内的客体反应性和催化作用。本研究以空穴和深空穴为骨架和宿主，重点研究了三类化学转化反应(环化反应、碳-碳双键的立体选择性卤化反应和芳香族化合物的卤化反应)。所有正在研究的化学转化都使用水作为溶剂，并利用疏水效应来驱动客体络合和/或促进周转。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

For several decades now, chemists have been learning from Nature how to harness the intrinsic properties of molecules to "self-assemble" into complex arrays that possess novel properties quite independent of the original components. This research program of Prof. Bruce Gibb at Tulane University utilizes bowl-shaped molecules in assembly processes that form novel chemical reactors. Although akin to the familiar test-tube, these chemical reactors are exceedingly small. Much like Nature's catalysts - enzymes - these reactors are capable of trapping one molecule at a time to bring about novel and selective chemical transformations. Additionally, the program of research is designed to improve our understanding of chemical transformations using exceedingly mild conditions (e.g., room temperature water). This research is important to society because it addresses national needs in sustainability. The use of room temperature water helps to reduce energy cost for production of chemicals and avoid environmental issues associated with the use of organic solvents. Broader impacts of the research include education and training of graduate and undergraduate students as the next generation of productive members and leaders in the chemical sciences, as well as outreach activities designed to promote chemistry within the local community and to broaden participation in science and engineering fields.The state-of-the-art of supramolecular chemistry has now reached a point that the construction of (supra)molecular containers is relatively facile. Building on this, a significant aim of this program of research is to consider how electrostatic potential fields within nano-spaces can be engineered, and in doing so, how it is possible to control guest reactivity and catalysis within the nano-space. This program of research focuses on three classes of chemical conversions (cyclization reactions, stereoselective halogenation of carbon-carbon double bonds, and halogenation of aromatic compounds) using cavitands and deep-cavity cavitands as scaffolds and hosts. All of the chemical conversions being studied utilize water as the solvent and take advantage of the hydrophobic effect to drive guest complexation and/or promote turnover.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.