This paper reports the biomimetic catalytic properties of new Schiff base mononuclear complexes MH 2L{M = Mn(Ⅱ), Fe(Ⅲ)Cl, Cr(Ⅲ)Cl, Cu(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ); L=bis[ N,N′-ethylene-2,2′-(phenylmethylene)bis(3,4-dimethylpyrrole-5-aldimino)]}and dinuclear complexes MnML[M=Mn(Ⅱ), Fe(Ⅲ)Cl, Cr(Ⅲ)Cl, Cu(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ)] for studying the monooxygenation of cyclohexane with PhIO and magnetic properties of the dinuclear complexes. The investigation of the magnetic properties(4—300 K) of the dinuclear complexes revealed that their antiferromagnetic spin exchange with J varied from -10.49 to -0.482 cm -1 except MnZnL, and antiferromagnetic spin exchange decreased in the order: Mn(Ⅱ)-Cu(Ⅱ)>Mn(Ⅱ)-Ni(Ⅱ)>Mn(Ⅱ)-Mn(Ⅱ)>Mn(Ⅱ)- Fe(Ⅲ)>Mn(Ⅱ)-Co(Ⅱ)>Mn(Ⅱ)-Cr(Ⅲ). The yield determination of monooxygenation of cyclohexane indicated that the catalytic reactivity of the dinuclear complex was better than that of the corresponding mononuclear complex, so we supposed that there was some cooperative action between the two metals in these dinuclear complexes. It was found that the cooperation lay in the decreasing order: Mn-{Fe>}Mn-Cr>Mn-Cu>Mn-Mn>Mn-Co>Mn-Ni>Mn-Zn. It seems that this cooperation increased with the increase of the number of unpaired d electrons and the magnetic exchange between the two metals in these dinuclear complexes.