Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, London W12 0BZ, United Kingdom.
Acc Chem Res. 2022 Feb 1;55(3):391-401. doi: 10.1021/acs.accounts.1c00657. Epub 2022 Jan 11.
Metal-containing polymers, or metallopolymers, have diverse applications in the fields of sensors, catalysis, information storage, optoelectronics, and neuromorphic computing, among other areas. The approach of metal-templated subcomponent self-assembly using dynamic covalent linkages allows complex architectures to be formed with relative synthetic ease. The dynamic nature of the linkages between subunits in these systems facilitates error checking during the assembly process and also provides a route to disassemble the structure, rendering these materials recyclable. This Account summarizes a class of double-helical metallopolymers. These metallopolymers are formed via subcomponent self-assembly and consist of two conjugated helical strands wrapping a linear array of Cu centers. Starting from discrete model helicates, we discuss how, through the judicious design of subcomponents, long helical metallopolymers can be obtained and detail their subsequent assembly into nanometer-scale aggregates. Two approaches to generate these helical metallopolymers are compared. We describe methods to govern (i) the length of the metallopolymers, (ii) the relative orientations (head-to-head vs head-to-tail) of the two organic strands, and (iii) the screw-sense of the double helix. Achieving structural control allowed the growth behavior of these systems to be probed. The structure influenced properties in ways that are relevant to specific applications; for example, the length of the metallopolymer determines the color of the light it emits in solution. In the solid state, the ionic nature of these helices renders them useful as both emitters and ionic additives in light-emitting electrochemical cells. Moreover, recent experimental work has clarified the role of the linear array of Cu ions in the transport of charge through these materials. The conductivity displayed by a film of metallopolymer depends upon its history of applied voltage and current, behavior characteristic of a memristor. In addition to the prospective applications already identified, others may be on the horizon, potentially combing stimuli-responsive electronic behavior with the chirality of the helical twist.
含金属聚合物，或金属聚合物，在传感器、催化、信息存储、光电和神经形态计算等领域有多种应用。使用动态共价键的金属模板亚组件自组装方法允许相对容易地形成复杂的结构。这些系统中亚组件之间键的动态性质在组装过程中有助于检查错误，并提供了一种拆卸结构的途径，使这些材料可回收。本账户总结了一类双螺旋金属聚合物。这些金属聚合物是通过亚组件自组装形成的，由两个包裹线性 Cu 中心阵列的共轭螺旋链组成。从离散的模型螺旋配合物开始，我们讨论了如何通过亚组件的精心设计来获得长螺旋金属聚合物，并详细介绍了它们随后组装成纳米级聚集体的过程。比较了两种生成这些螺旋金属聚合物的方法。我们描述了控制（i）金属聚合物长度、（ii）两个有机链相对取向（头对头与头对尾）和（iii）双链螺旋螺旋手性的方法。实现结构控制允许探测这些系统的生长行为。结构以与特定应用相关的方式影响性质；例如，金属聚合物的长度决定了其在溶液中发射光的颜色。在固态下，这些螺旋的离子性质使它们成为发光电化学电池中发射体和离子添加剂的有用材料。此外，最近的实验工作澄清了线性 Cu 离子阵列在这些材料中电荷传输中的作用。金属聚合物薄膜的电导率取决于其施加电压和电流的历史，这是忆阻器的特征行为。除了已经确定的预期应用外，其他应用可能也即将出现，这可能将对刺激响应的电子行为与螺旋扭曲的手性相结合。
