Eccentricities in Spectroscopy and Reactivity of Non‐Heme Metal Intermediates Contained in Bispidine Scaffolds

Abstract

AbstractLigand framework in a metal complex has a pivotal role to play in orchestrating the spectroscopic and reactivity parameters. High‐valent non‐heme metal intermediates are known to be crucial species in the catalytic cycles of several metalloenzymes. Among the plethora of a variety of ligand frameworks employed in bioinorganic chemistry, the bispidine molecular scaffold is unique and privileged. In this review, we intend to discuss the overwhelming effects of the bispidine ligand scaffold in tuning the spectroscopic signatures and reactivity parameters of non‐heme metal intermediates. The basic skeleton constituting a fused and rigid bicyclic diamine framework with its tentacles tethered to C2, C4, N3 and N7 provides tuneable features to both the primary and secondary coordination spheres. Therefore, the bispidine framework offers a handle to optimize the balance of rigidity and flexibility in a coordination molecule which is thereby important in understanding the rich but surprising results in the reactivity of metal intermediates contained in these scaffolds. Herein, we summarize the significant developments in different types of oxidation reactions of reactive metal intermediates stabilized in bispidine ligands and noted their mechanistic details.