Next Generation Catalyst Transfer Polycondensations

密歇根大学安娜堡分校的Anne J.McNeil教授得到化学系化学催化(CAT)计划的支持，开发催化合成程序，以制造具有改进结构控制的导电聚合物。导电聚合物代表了聚合物的一个有趣的子集，这些聚合物被用作太阳能电池的捕光层、二极管(即LED)的发光层和晶体管的电荷导电层。导电聚合物的一个关键优势是它们是柔性的，因此可以使用简单的高通量技术(例如喷墨打印)将它们涂覆到柔性基材上。此外，起始材料也不贵。因此，导电聚合物市场正在迅速增长，预计到2017年，美国的导电聚合物市场将达到16亿美元。这项研究的目的是拓宽可以制造的聚合物的类型，同时增加制备过程的用户友好性。制备了沿着聚合物链具有可变组成的聚合物。其目的是提高聚合物太阳能电池的稳定性和寿命。鉴于共轭聚合物被广泛用于许多应用，该项目可能会对科学界和整个社会产生更广泛的影响。在这项工作的过程中，学生们接受了有机、无机、有机金属和聚合物的合成和表征、机械有机金属化学、太阳能电池制造和测试方面的培训。来自历史上代表性不足的群体的学生通过参加密歇根数学和科学学者计划以及与华盛顿社区学院的研究伙伴关系参与了该项目。梯度序列共轭共聚物被制备并评估用于太阳能电池的相容剂。聚合物的组成、长度和顺序都是影响聚合物性能的关键因素。因此，每种应用通常需要合成不同的聚合物结构。共聚物是用钯催化剂按照催化剂转移缩聚(CTP)机制制备的。然而，目前的CTP方法有许多局限性，包括对氧气和水分的敏感性，以及许多官能团不被容忍，大单体很难聚合，以及很少有缺电子单体被聚合。这项研究的目的是确定官能团容忍和用户友好的链生长方法，并使含有缺电子芳烃的大单体聚合成为可能。一旦优化，这些方法将被应用于用于增容太阳能电池的具有侧链富勒烯的更高性能聚合物(超越聚(3-己基噻吩基))的梯度共聚合成。由此产生的机理洞察和催化发现可能会引起合成有机、有机金属和聚合物化学界的兴趣。

Professor Anne J. McNeil of the University of Michigan Ann Arbor is supported by the Chemical Catalysis (CAT) program in the Division of Chemistry to develop catalytic, synthetic procedures to make polymers that conduct electricity with improved structural control. Conductive polymers represent an interesting subset of polymers that are used as the light-harvesting layer in solar cells, the light-emitting layer in diodes (i.e., LEDs), and the charge conducting layer in transistors. One key advantage of conductive polymers is that they are flexible, and therefore they can be coated onto flexible substrates using simple, high-throughput technologies (e.g., ink-jet printing). Moreover, the starting materials are inexpensive. As a consequence, the conductive polymers market is rapidly growing and expected to reach 1.6 billion dollars in the US by 2017. The goal of this research is to broaden the types of polymers that can be made, and at the same time, increase the user-friendliness of the preparation procedure. Polymers with variable composition along the polymer chain are prepared. The objective is to improve the robustness and lifetime of polymer-based solar cells. The project may have a broader impact on the scientific community and the society at large, given that conjugated polymers are widely used for many applications. During the course of this work, students are trained in organic, inorganic, organometallic and polymer synthesis and characterization, mechanistic organometallic chemistry, solar cell fabrication and testing. Students from historically underrepresented groups are involved in the project through participation in the Michigan Math and Science Scholars Program and the research partnership with Washtenaw Community College.Gradient sequence conjugated copolymers are prepared and evaluated for use as compatibilizers in solar cells. Polymer composition, length, and sequence are all crucial factors that influence the properties of the polymer. As a result, each application often requires different polymer structure to be synthesized. The copolymers are prepared using palladium catalysts following a mechanism known as catalyst-transfer polycondensation (CTP). Current CTP methods, however, have many limitations, including sensitivity to oxygen and moisture and the fact that many functional groups are not tolerated, large monomers are difficult to polymerize, and few electron-deficient monomers have been polymerized. The aim of this research is to identify chain-growth methods that are functional group tolerant and user-friendly, and to enable polymerization of large monomers containing electron-deficient arenes. Once optimized, the methods are applied to the gradient copolymer synthesis of higher-performing polymers (beyond poly (3-hexylthiophene)) with side chain fullerene for compatibilizing solar cells. The resulting mechanistic insight and catalysis discoveries may interest the synthetic organic, organometallic and polymer chemistry communities.