Lewis Pair Polymerization: Controlling Polymer Tacticity and Topology

路易斯对聚合：控制聚合物立构性和拓扑结构

• 批准号: 1904962
• 负责人: Eugene Chen
• 金额: $ 66.43万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904962&HistoricalAwards=false
• 关键词: Lewis; Pair; Polymerization; Controlling; Polymer

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Eugene Y. Chen of the Department of Chemistry at Colorado State University is developing new synthetic routes for the construction of industrially-important stereoregular polymeric materials. Stereochemistry is an essential aspect of chemistry that generally focuses on compounds in which carbon atoms are attached to four different groups. The specific arrangement of the groups on a carbon gives rise to mirror images that cannot be superimposed; These mirror images are called chiral molecules and they occur in pairs. [Notably, human hands are also chiral because the left hand is a mirror image of the right hand, but one cannot turn or move one of the hands to look exactly the same as the other.] Chirality is property that dictates biological, thermal and mechanical properties of compounds or materials. In the case of polymers, which are large molecules made by linking a large number of carbons together, the number of chiral possibilities can be very large. For example, in a relatively small polymer consisting of only 30 carbon atoms, the maximum number of unique chiral configurations is estimated at a billion. This research develops sophisticated methodologies that control and fine tune the number of chiral outcomes during the preparation of polymers, yielding a completely new and previously unexplored class of plastic materials. The activities associated with this award increase broadening participation and enable training of undergraduate and graduate students in the industrially-important field of polymer chemistry.In this work, a next generation Lewis pair polymerization (LLP) system is developed that can control the stereochemical outcomes and topologies of the resulting polymers, thereby enabling facile access to advanced polymeric materials with different tacticities or stereomicrostructures and cyclic topological structures. LLP methodology relies on an interacting or frustrated Lewis pair (LP) and exploits the synergy and cooperativity between the Lewis acidic and basic sites of LPs to effect cooperative monomer activation as well as chain initiation, propagation, termination and transfer events. The research includes synthetic, catalytic and mechanistic approaches, coupled with synergistic theoretical and computational methods. Investigated monomers include industrially-important polar vinyl monomers and crotonic esters. The latter monomers provide access to unique ditactic polymers which are currently unobtainable by other synthetic methods. Additionally, topological and stereochemical control in the LPP of acrylic monomers enables selective synthesis of cyclic acrylic polymers in chiral helical or achiral forms. The research in this work is highly innovative and transformative with the potential to significantly impact not only the field of polymer chemistry, but also synthetic organic chemistry and catalysis in general. Through carefully designed and planned activities, the research team provides tangible solutions to the control of tacticity, which has been traditionally one of the main weaknesses in modern synthetic polymer chemistry.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.

在这个由化学系大分子、超分子和纳米化学计划资助的项目中，科罗拉多州立大学化学系的Eugene Y.Chen教授正在为构建具有工业重要性的立体规则聚合物材料开发新的合成路线。立体化学是化学的一个基本方面，通常侧重于碳原子连接到四个不同基团的化合物。碳上基团的特定排列产生了不能重叠的镜像；这些镜像被称为手性分子，它们成对出现。[值得注意的是，人类的手也是手性的，因为左手是右手的镜像，但一个人不能转动或移动一只手来让另一只手看起来完全一样。]手性是决定化合物或材料的生物、热和机械性能的性质。在聚合物的情况下，它是通过将大量的碳连接在一起而形成的大分子，手性可能性的数量可能非常大。例如，在只有30个碳原子的相对较小的聚合物中，独特的手性构型的最大数量估计为10亿。这项研究开发了复杂的方法来控制和微调聚合物制备过程中手性产物的数量，产生了一种全新的、以前从未探索过的塑料材料。与该奖项相关的活动增加了更多的参与者，并使本科生和研究生能够在重要的工业聚合物化学领域进行培训。在这项工作中，开发了新一代Lewis对聚合(LLP)系统，该系统可以控制所得聚合物的立体化学结果和拓扑结构，从而使人们能够轻松地获得具有不同触感或立体微结构和环状拓扑结构的先进聚合物材料。LLP方法依赖于相互作用或受挫的Lewis对(LP)，并利用LP的Lewis酸性和碱性中心之间的协同和协同作用来实现协同单体激活以及链的引发、繁殖、终止和转移事件。研究包括合成法、催化法和机械法，并结合协同理论和计算方法。所研究的单体包括工业上重要的极性乙烯基单体和巴豆酸酯。后一种单体提供了独特的双规聚合体，这是目前其他合成方法无法获得的。此外，通过对丙烯酸酯单体LPP的拓扑和立体化学控制，可以选择性地合成手性螺旋或非手性形式的环状丙烯酸酯聚合物。这项工作的研究具有很高的创新性和变革性，不仅有可能对聚合物化学领域产生重大影响，而且可能对合成有机化学和一般催化领域产生重大影响。通过精心设计和计划的活动，研究团队为控制规则性提供了切实的解决方案，这一直是现代合成聚合物化学的主要弱点之一。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。

项目成果

Synchronous Control of Chain Length/Sequence/Topology for Precision Synthesis of Cyclic Block Copolymers from Monomer Mixtures

• DOI: 10.1021/jacs.1c00561
• 发表时间: 2021-02-27
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: McGraw, Michael L.;Clarke, Ryan W.;Chen, Eugene Y. -X.
• 通讯作者: Chen, Eugene Y. -X.

Thermomechanical activation achieving orthogonal working/healing conditions of nanostructured tri-block copolymer thermosets

• DOI: 10.1016/j.xcrp.2021.100483
• 发表时间: 2021-07-21
• 期刊: CELL REPORTS PHYSICAL SCIENCE
• 影响因子: 8.9
• 作者: Clarke, Ryan W.;McGraw, Michael L.;Chen, Eugene Y. -X.
• 通讯作者: Chen, Eugene Y. -X.

Lewis Pair Polymerization: Perspective on a Ten-Year Journey

• DOI: 10.1021/acs.macromol.0c01156
• 发表时间: 2020-08-11
• 期刊: MACROMOLECULES
• 影响因子: 5.5
• 作者: McGraw, Michael L.;Chen, Eugene Y-X
• 通讯作者: Chen, Eugene Y-X

Compounded Sequence Control in Polymerization of One-Pot Mixtures of Highly Reactive Acrylates by Differentiating Lewis Pairs

• DOI: 10.1021/jacs.0c01127
• 发表时间: 2020-04-01
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: McGraw, Michael L.;Clarke, Ryan W.;Chen, Eugene Y-X
• 通讯作者: Chen, Eugene Y-X

Compounded Interplay of Kinetic and Thermodynamic Control over Comonomer Sequences by Lewis Pair Polymerization

• DOI: 10.1021/jacs.2c10568
• 发表时间: 2022-12-15
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Reilly，Liam T.;McGraw，Michael L.;Chen，Eugene Y-X
• 通讯作者: Chen，Eugene Y-X