Ground-state electronic and magnetic properties of MS2−4 derived trinuclear M-Fe-S complexes (M = Mo, W)

Abstract Three trinuclear complex anions, [(FeCl 2 ) 2 MS 4 ] 2− (M = Mo, W) and [(MoS 4 ) 2 Fe] 3− , were studied by Mossbauer and magnetic measurements. The results imply a high electron affinity of the MS 2− 4 group and intramolecular spin coupling. These properties and structural features suggest these molecular groups as possible building blocks of the Fe-Mo co-factor of the nitrogen fixing enzyme nitrogenase.