Development of Controlled Palladium(0)-Catalyzed Suzuki Cross-Coupling Polymerizations

化学系的大分子、超分子和纳米化学项目正在支持纽约城市大学史泰登岛学院的胡乔生教授开发新方法来制备传统方法难以合成的共轭聚合物。共轭聚合物在从半导体、传感器到光电子等领域都有应用。除了提高聚合化学的基础知识外，本研究旨在生产具有潜在应用价值的新型共轭聚合物作为光电材料。作为该项目更广泛影响的一部分，胡氏集团正在用最先进的仪器和技术培训学生和研究生，以制备和表征先进材料。胡教授的研究小组试图利用Pd(0)催化的铃木交叉偶联化学来控制聚合，以制备共轭聚合物/嵌段共聚物。可控Pd(0)催化的交叉偶联聚合是近年来合成聚合度可控的聚芳烯和聚芳烯-乙炔等共轭聚合物的新手段。然而，目前报道的可控Pd(0)催化的交叉偶联聚合存在局限性，包括有前景但不理想的多分散性指数（pdi）（一般约为1.20），有限的单体范围，例如主要是基于供体的ab型单体，以及难以控制链端官能团。这些限制极大地阻碍了它们作为制备许多有价值的共轭聚合物和嵌段共聚物的有力工具的应用，这些聚合物和嵌段共聚物在分子电子学和纳米技术以及从半导体、传感器到光电子学等领域具有巨大的潜力。在这个项目中，具体的重点是：(a)制备新的基于palladacycle的引发剂；(b)发展Pd(0)催化的受体基单体和供体-受体单体铃木交叉偶联聚合，用于制备ab型和AA/ bb型聚合物和嵌段共聚物。所得材料通过尺寸排斥色谱、基质辅助激光解吸/电离飞行时间质谱、核磁共振波谱和其他表征技术进行分析。

With this award, the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry is supporting Professor Qiao-Sheng Hu of the City University of New York-College of Staten Island to develop new approaches to preparing conjugated polymers that are difficult to synthesize by conventional methods. Conjugated polymers have applications in fields ranging from semiconductors, sensors to opto-electronics. In addition to advancing the fundamental knowledge of polymerization chemistry, this research aims to produce new conjugated polymers with potential application as opto-electronic materials. As a part of the broader impacts of this project, the Hu Group is training students and graduate students with state-of-art instruments and techniques for the preparation and characterization of advanced materials. Professor Hu's research group seeks to exploit Pd(0)-catalyzed Suzuki cross-coupling chemistry for controlled polymerizations in the preparation of conjugated polymers/block copolymers. Controlled Pd(0)-catalyzed cross-coupling polymerizations have recently emerged as new tools for the synthesis of conjugated polymers such as poly(arylene)s and poly(aryleneethynylene)s with controlled degree of polymerization. However, limitations exist for reported controlled Pd(0)-catalyzed cross-coupling polymerizations, which include promising but less than ideal polydispersity indexes (PDIs)(~1.20 in general), limited monomer scope, e.g., mainly donor-based AB-type monomers, and difficulty to control chain end functionality. Such limitations greatly impede their applications as powerful tools for the preparation of many valuable conjugated polymers and block copolymers with controlled length, which have great potential in molecular electronics and nanotechnology as well as in fields ranging from semiconductors, sensors to optoelectronics. In this project, the specific foci are: (a) the preparation of new palladacycle-based initiators; and (b) the development of controlled Pd(0)-catalyzed Suzuki cross-coupling polymerizations of acceptor-based and donor-acceptor monomers for the preparation of AB-type and AA/BB-type polymers and block copolymers. The resulting materials are analyzed by size exclusion chromatography, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, nuclear magnetic resonance spectroscopy and other characterization techniques.