Tuning Electronic Structure To Control Manganese Nitride Activation.

Investigation of a series of oxidized nitridomanganese(V) salen complexes with different para ring substituents (R = CF3, tBu, and NMe2) demonstrates that nitride activation is dictated by remote ligand electronics. For R = CF3 and tBu, oxidation affords a Mn(VI) species and nitride activation, with dinitrogen homocoupling accelerated by the more electron-withdrawing CF3 substituent. Employing an electron-donating substituent (R = NMe2) results in a localized ligand radical species that is resistant to N coupling of the nitrides and is stable in solution at both 195 and 298 K.