Modulating electronic structure and reactivity of Cr nitride complexes via xxidation

Metal nitride complexes exhibit interesting structure and bonding properties that are invoked when discussing the reactivity of these systems. The nitride (N3-) moiety can be either nucleophilic or electrophilic based on a variety of factors such as metal identity, oxidation state, and nature of the ancillary ligands. Herein, the electronic tuning of Cr salen nitride complexes is investigated via modulation of phenolate para-R substituents of varying electron donating ability (R = CF3, tBu, NMe2) in order to influence reactivity. Salen ligands can exhibit non-innocent behavior, implying that redox processes can either be metal or ligand-based. This feature allows the ligand to help facilitate difficult substrate transformations uncommon to Earth-abundant first-row metals. Depending on the para-R group, the locus of oxidation in Cr nitride salen complexes (metal vs. ligand) can be influenced. The electronic structure of oxidized compounds is detailed, allowing for rationalization of nitride reactivity based on oxidation locus.