Diiminepyridines are a well-known class of “non-innocent” ligands that confer additional redox activity to coordination complexes beyond metal-centred oxidation/reduction. Here, we demonstrate that metal coordination complexes (MCCs) of diiminepyridine (DIP) ligands with iron are suitable anolytes for redox-flow battery applications, with enhanced capacitance and stability compared with bipyridine analogs, and access to storage of up to 1.6 electron equivalents. Substitution of the ligand is shown to be a key factor in the cycling stability and performance of MCCs based on DIP ligands, opening the door to further optimization.

中文翻译：

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氧化还原非纯双（2,6-二亚胺-吡啶）配体-铁配合物作为液流电池应用中的阳极电解液

二亚胺吡啶是一类众所周知的“非纯”配体，除了以金属为中心的氧化/还原作用外，还赋予配位配合物以额外的氧化还原活性。在这里，我们证明了二亚胺吡啶（DIP）配体与铁的金属配位络合物（MCC）是适合氧化还原液流电池应用的阳极电解液，与联吡啶类似物相比具有增强的电容和稳定性，并且可以存储多达1.6个电子当量。配体的取代被证明是基于DIP配体的MCC循环稳定性和性能的关键因素，这为进一步优化打开了大门。