Abstract: Aerial oxidation of solution of chemically synthesized Mo-Fe-Scluster [Cl₂FeS₂MoS₂FeCl₂]^2-has been shown to yield a 1. 50: 1 mixture of MoOS₃^2-and MoS₄^2-.It is evident that the ratio of the concentration of MoOS₃^2-and MoS₄^2-is lower than that produced by the oxidative degradation of natural FeMo-co (△C_MoOS3^2-/△C_MoS4^2- =3:1), so it can be inferred that the oxidative degradation of the cluster containing MoS₄core can not give the same result with the oxidative degradation of natural FeMo-co, and there should be three sulfur atoms in molybdenum-micro-surrounding on nitrogenase.

Key words: Nitrogenase, Molybdenum-micro-surronding, Mo-Fe-S cluster, Oxidativedegradation