Nitrogen dioxide reactivity of a Nickel(II) complex of tetraazacyclotetradecane ligand

Reaction of a Ni(II) complex of ligand L (L=meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) (1) in methanol with NO2 has been studied. Addition of equivalent amount of NO2 resulted in the reduction of Ni(II) to Ni(I). The Ni(I) intermediate reacted with further equivalent of NO2 to form Ni(II)-O-nitrito complex, [NiII(L)(η1-ONO)2] (2). Subsequent equivalent of NO2 resulted in the oxo transfer from NO2 to the metal bound nitrito group leading to the formation of O-nitrato complex, [NiII(L)(η1-ONO2)]+ (3) with simultaneous release of NO.