CAS: Electrochemical and Photochemical Methods for Precision Synthesis of Conjugated Polymers

在化学系大分子、超分子和纳米化学项目的支持下，加州大学圣地亚哥分校的Nathan Romero正在开发用于精确合成共轭聚合物的电化学和光化学方法。 共轭聚合物具有质轻、柔性和多样的光电性能，在有机电子材料方面具有重要的应用潜力。然而，先进技术的实现需要一定程度的结构控制超出目前的合成能力。 这项工作解决了这一限制，并将寻求实现长度和序列控制的共轭聚合物的聚合，使用电化学和光化学工具的组合，以取代广泛的简单芳烃基板。开发的方法将应用于有机电子产品的新型聚合物的合成和增材制造的新方法。与这项研究相关的合成创新有可能创造出先进的有机电子设备，并应用于可持续能源、医疗保健和通信领域。此外，单体的设计的光化学反应性可适用于共辄聚合物一旦使用就升级循环，而不是将这些作为废物丢弃。这项研究的跨学科性质将为学生研究人员提供教育和专业发展的机会。研究团队将通过包容性的指导、教学和服务，努力增加非多数派学者的代表性。 对当地社区的外联活动将侧重于与电子废物处理和处置、可持续聚合物原料和生物降解塑料有关的教育资源，这项研究将侧重于开发使用电化学和光化学工具相结合的噻吩基单体的长度和序列控制聚合。 用于精确合成共轭聚合物的模块化平台将利用电化学C-H官能化来选择性地偶联芳烃和硫化物以形成芳基锍盐，其也将在新型光介导的链生长聚合中充当单体。通过同时进行电解和光解，硫化物将基本上充当催化剂以实现受控的氧化聚合。 开发的通过C-H官能化制备芳基锍盐的直接方法旨在改进现有多步化学方法的原子经济性。光聚合研究有可能提供共轭聚合物的光化学反应性的基础知识，并引入概念上的新机制，通过波长调制控制分子量。减少对用于聚合芳族单元的过渡金属的依赖的策略对于提高聚合物科学和技术的可持续性是重要的。总的来说，这项研究有可能为共轭聚合物的序列定义和控制聚合提供一种更通用的方法。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Nathan Romero of the University of California at San Diego is developing electrochemical and photochemical methods for precision synthesis of conjugated polymers. Conjugated polymers carry significant potential for applications as organic electronic materials owing to their lightweight, flexible nature and diverse optoelectronic properties. However, realization of advanced technologies necessitates a degree of structural control beyond current synthetic capabilities. This work addresses this limitation and will seek to achieve length- and sequence-controlled polymerization of conjugated polymers using a combination of electrochemical and photochemical tools to polymerize a broad range of simple arene substrates. The developed methodology will be applied to the synthesis of novel polymers for organic electronics and new methods for additive manufacturing. The synthetic innovations associated with this research have the potential to create advanced organic electronic devices with applications in sustainable energy, healthcare, and communications. Furthermore, the designed photochemical reactivity of monomers may be applicable to the upcycling of conjugated polymers once used rather than discard these as waste. The interdisciplinary nature of this research will provide educational and professional development opportunities for student researchers. The research team will work to increase representation of non-majority scholars through inclusive mentoring, teaching and service. Outreach activities to local communities will focus on educational resources related to electronic waste handling and disposal, sustainable polymer feedstocks and biodegradable plastics.This research will focus on developing the length- and sequence-controlled polymerization of thiophene based monomers using a combination of electrochemical and photochemical tools. The modular platform for precision synthesis of conjugated polymers will utilize electrochemical C-H functionalization to selectively couple an arene and a sulfide to form an arylsulfonium salt, which will also serve as monomer in a novel photo-mediated chain growth polymerization. By performing electrolysis and photolysis simultaneously, the sulfide will essentially act as a catalyst to achieve controlled oxidative polymerization. The developed direct method for the preparation of arylsulfonium salts through C-H functionalization aims to improve upon the atom economy of existing multi-step chemical methods. The photopolymerization studies have the potential to provide fundamental knowledge on the photochemical reactivity of conjugated polymers and introduce conceptually novel mechanisms for controlling molecular weight through wavelength modulation. Strategies that reduce the reliance on transition metals for polymerizing aromatic units are important for improving the sustainability of polymer science and technology. In general terms, this research has the potential to provide a more universal approach to sequence-defined and controlled polymerizations of conjugated polymers.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.