Programming Supramolecular Polymer Structure and Function Using Covalently-Fixed Monomers

在化学系大分子、超分子和纳米化学项目的支持下，佛罗里达大学(UF)的Ronald Castellano教授将开发一种新型的合成超分子聚合物，这些聚合物由新型的分子构建块--环状和手性单体制成。结构-性能研究将利用设计的稳健性来控制与潜在下游应用相关的超分子聚合物的热力学、机理和光电性能。在最广泛的意义上，这项研究旨在帮助人们从根本上理解如何在纳米/介观尺度上控制有机物的三维结构，以加速下一代材料的发展。对教育和培训的更广泛影响来自：(1)研究生和本科生接触合成和物理有机化学、光谱学、计算和聚合物表征；(2)通过与密歇根大学ACSPoly/PMSE学生分会、UF化学俱乐部和当地退休社区合作的外联活动，向社区介绍科学的各个方面；(3)扩大服务不足群体的成员对科学研究的参与。本研究旨在通过两个独立的自组装单体的共价桥联(共价固定)来开发均手性一维超分子聚合物，以创建平面手性结构，减少构象自由度，并建立强大的、持久的跨环氢键。这项工作中使用的主要载体是[N.N]对环芳烃([N.N]PCP)，其中设计涉及在对环芳烃支架上以交叉图案引入互补的氢键基团。[N.N]PCP将化学和立体化学信息亲密地传递给不断增长的组装中的邻居。将进行广泛的结构-性质研究，包括实验和理论，以(1)开发甲板差别化环番，通过电子互补的甲板内和甲板间相互作用来控制超分子聚合物组装的热力学和机理，(2)将环番甲板扩展到有用的生色团，以及(3)研究能够自我折叠然后进行一维超分子聚合的最低限度单体。结构-性质研究寻求提供信息，使研究人员能够在设计这些系统和相关系统时达到超分子组装热力学和动力学结果的原子水平控制的新水平。这一奖项反映了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。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Ronald Castellano of the University of Florida (UF) will develop a new class of synthetic supramolecular polymers that are made from novel molecular building blocks, monomers, that are cyclic and chiral. Structure-property investigations will exploit the robustness of the design to control supramolecular polymer thermodynamics, mechanism, and optoelectronic properties relevant to potential downstream applications. In the broadest sense, this research aims to contribute to a fundamental understanding of how to control the 3D structure of organic matter at the nano-/mesoscale to accelerate development of next-generation materials. Broader impacts with respect to education and training come from (1) graduate and undergraduate students being exposed to synthetic and physical organic chemistry, spectroscopy, computation, and polymer characterization; (2) introducing aspects of the science to the community through outreach activities in partnership with the UF ACS POLY/PMSE student chapter, the UF Chemistry Club, and a local retirement community; (3) broadening the participation of members of underserved groups in scientific research. This research aims to develop homochiral 1D supramolecular polymers through the covalent bridging of two otherwise independently self-assembling monomers (“covalent-fixation”) to create a planar chiral structure, reduce conformational degrees of freedom, and establish strong, persistent transannular hydrogen bonding. The primary vehicles to be used in the work are [n.n]paracyclophanes ([n.n]pCps), where the design involves introduction of complementary hydrogen-bonding groups in a cross pattern on the paracyclophane scaffold. The [n.n]pCps intimately transfer chemical and stereochemical information to their neighbors within a growing assembly. Extensive structure-property studies, involving both experiment and theory, will be conducted to (1) develop deck-differentiated cyclophanes to control supramolecular polymer assembly thermodynamics and mechanism through electronically complementary intra- and inter-deck interactions, (2) expand the cyclophane decks to useful chromophores, and (3) examine minimalist monomers capable of self-folding and then 1D supramolecular polymerization. The structure-property studies seek to provide information that will allow investigators to achieve new levels of atomic level control of supramolecular assembly thermodynamic and kinetic outcomes in designing these and related systems.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.