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 (Mes(2)ArCO(2)(-)). Among the compounds isolated are the potentially useful heterobimetallic synthon Tl(mu-Mes(2)ArCO(2))(3)Fe(NO) and a novel cubane Fe-4(Mes(2)ArCO(2))(4)(NO)(4)(mu 3-OH)(4) that forms in the presence of added H2O and features syn-[FeNO](2) units.