Elaboration on the Electronics of Salen Manganese Nitrides: Investigations into Alkoxy-Substituted Ligand Scaffolds

Abstract

The ligand electronics of salen manganese nitride complexes directly influence the locus of oxidation and, thus, the reactivity of the resulting oxidized species. This work investigates the influence of <i>tert</i>-butoxy, isopropoxy, and methoxy substituents on the electronics of salen manganese nitride species and includes the first documentation of the para Hammett value for the <i>tert</i>-butoxy substituent (σ_para = -0.13 ± 0.03). Each alkoxy-substituted complex undergoes metal-based oxidation to form manganese(VI), and the kinetics of bimolecular homocoupling to form N₂ were assessed by cyclic voltammetry. Bis-oxidation of the manganese complexes was investigated at low temperature using cyclic voltammery and UV-vis-near-IR spectroscopy, and in combination with theoretical calculations, plausible electronic structures of the dications are provided.