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

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 tert-butoxy, iso-propoxy, and methoxy substituents on the electronics of salen manganese nitride species and includes the first documentation of the para-Hammett value for the tert-butoxy substituent (σpara = -0.13 ± 0.03). Each alkoxy substituted complex undergoes metal based oxidation to form Mn(VI) and the kinetics of bimolecular homocoupling to form N2 were assessed by cyclic voltammetry. Bis-oxidation of the Mn complexes was investigated at low-temperature using cyclic voltammery and UV-vis-NIR spectroscopy, and in combination with theoretical calculations, plausible electronic structures of the di-cations are provided.