Mononitrosyl Iron Complexes Supported by Sterically Hindered Carboxylate Ligands

Complexes that feature a single NO bound to Fe, as postulated in various carboxylate-rich metalloproteins, were prepared by mixing FeII salts, NO, and the sterically encumbered 2,6-dimesitylbenzoate (Mes2ArCO2-). Among the compounds isolated are the potentially useful heterobimetallic synthon Tl(μ-Mes2ArCO2)3Fe(NO) and a novel cubane Fe4(Mes2ArCO2)4(NO)4(μ3-OH)4 that forms in the presence of added H2O and features syn-[FeNO]2 units.