Structurally Modelling the 2‐His‐1‐Carboxylate Facial Triad with a Bulky N , N,O Phenolate Ligand

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We present the synthesis and coordination chemistry of a bulky, tripodal N , N,O ligand, Im Ph2 NNO t Bu ( L ), designed to model the 2‐His‐1‐carboxylate facial triad (2H1C) by means of two imidazole groups and an anionic 2,4‐di‐ tert ‐butyl‐subtituted phenolate. Reacting K‐L with MCl 2 (M = Fe, Zn) affords the isostructural, tetrahedral non‐heme complexes [Fe(L)(Cl)] ( 1 ) and [Zn(L)(Cl)] ( 2 ) in high yield. The tridentate N , N,O ligand coordination observed in their X‐ray crystal structures remains intact and well‐defined in MeCN and CH 2 Cl 2 solution. Reacting 2 with NaSPh affords a tetrahedral zinc thiolate complex, [Zn(L)(SPh)] ( 4 ), that is relevant to isopenicillin N synthase (IPNS) biomimicry. Cyclic voltammetry studies demonstrate the ligand's redox non‐innocence, where phenolate oxidation is the first electrochemical response observed in K‐L , 2 and 4 . However, the first electrochemical oxidation in 1 is iron‐centred, the assignment of which is supported by DFT calculations. Overall, Im Ph2 NNO t Bu provides access to well‐defined mononuclear, monoligated, N , N,O ‐bound metal complexes, enabling more accurate structural modelling of the 2H1C to be achieved.