Heterometallic supramolecular polymers: From synthesis to properties and applications

Heterometallic supramolecular polymers (HMSPs) comprising two or more heterometal ions have drawn significant research interest in the last two decades because of their attractive properties and applications owing to the combination of organic and inorganic segments in the polymer as well as that of heterometallic complexes in the polymer chain. However, the synthesis of HMSPs is challenging because of the different stabilities of heterometallic complexes. To date, various HMSPs have been developed via one-pot or stepwise synthetic approaches, in which heterometal ions are complexed in identical or different coordination environments. The properties of this type of polymers not only depend on the heterometal ions, but also on the coordination environments of heterometal ions. In this review, we summarize the progress made in the synthesis of HMSPs and highlight their properties and applications. In the first section, we comprehensively discuss various synthetic approaches to HMSPs with all relevant reported examples. Subsequently, we highlight the properties and applications explored in different research directions. Finally, we provide a perspective on the synthetic challenges and future research prospects for HMSPs. We believe that this review will provide a roadmap for further developments in this thriving area of research to create novel functional materials.