The chemical states of conjugated coordination polymers

Conjugated coordination polymers (CCPs) with extended pi-d conjugation can effectively facilitate the delocalization of charges, form a continuous electron transfer pathway, and enhance the stability, which enable their potential applications in various devices. However, the CCPs are so unique that the accurate chemical states or structures of most CCPs, such as the valence of metal ions, the single/ double bond characters of ligands, and the presence/absence of counter ions and radicals, still have disputations in the literature. Herein, we focus on disclosing the fundamental understanding of the chemical states and structures of CCPs based on our previous works and other literatures. The synthetic control for a desired/ideal structure with high crystallinity and the variation of chemical states during the charge storage further deepen the understanding of the chemical states of CCPs. On this basis, the challenges and opportunities for further development of CCPs are also prospected.