Zn-Templated synthesis of substituted (2,6-diimine)pyridine proligands and evaluation of their iron complexes as anolytes for flow battery applications
Date
2020-04-13
Authors
Braun, Jason
Gray, Paul
Sidhu, Baldeep K
Nemez, Dion
Herbert, David E
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
Pseudo-octahedral iron complexes supported by tridentate N^N^N-binding, redox ‘non-innocent’ diiminepyridine (DIP) ligands exhibit multiple reversible ligand-based reductions that suggest the potential application of these complexes as anolytes in redox flow batteries (RFBs). When bearing aryl groups at the imine nitrogens, substitution at the 4-position can be used to tune these redox potentials and impact other properties relevant to RFB applications, such as solubility and stability over extended cycling. DIP ligands bearing electron-withdrawing groups (EWGs) in this position, however, can be challenging to isolate via typical condensation routes involving para-substituted anilines and 2,6-diacetylpyridine. In this work, we demonstrate a high-yielding Zn-templated synthesis of DIP ligands bearing strong EWGs. The synthesis and electrochemical characterization of iron(II) complexes of these ligands is also described, along with properties relevant to their potential application as RFB anolytes.
Description
Keywords
Coordination Chemistry
Citation
Dalton Transactions 2020, 49, 16175-16183