Abstract:

With the development of synthetic chemistry, more and more efficient catalysts are exploited to activate inert chemical bonds and organic molecules. In the synthetic chemistry, catalysts play an important role, scientists are paying more and more attention to the design and synthesis of catalysts. The majority of catalysts in homogeneous catalytic systems belong to mononuclear active species. In addition to the development of catalysis science, major research is also being conducted on the development of the coordination environment for metal centers to increase their catalytic ability and thereby create enhanced catalytic processes. The catalytic activity of dinuclear catalysts varies from those of mononuclear catalysts. Due to the synergistic effect between the two metal centers, the catalytic activity of dinuclear catalytic systems exhibits particular performance characteristics. The first row of elements in group Ⅷ of the periodic table, Fe, Co, and Ni, are also known as the ferrous group. These metals have drawn attention in recent years because of their relatively low price, stable structure, commercial availability, and ability to catalyze various type of reactions. Homodinuclear ferrous group metal complexes are applied in a wide variety of reactions, including hydroboration, hydrosilylation, cross-coupling reactions, asymmetric 1, 4-addition, asymmetric Mannich reactions, CO₂ activation, copolymerization, and alkyne cyclotrimerizations. Compared with mononuclear metal catalytic systems, there are currently relatively few types of homogenous catalytic systems that are catalyzed by bimetal catalysts. However, such catalytic systems possess significant advantages over mononuclear catalytic systems. For example, the catalytic activity and reaction selectivity of dinuclear metal catalytic systems are far superior, the reaction conditions milder, and the operations required simpler. However, research on the mechanisms of dinuclear metal catalytic systems is still insufficient. For example, the interaction between metals and substrates requires further investigation. This review focusses on the synthesis and characterization of homodinuclear bimetallic iron complexes. The application of homodinuclear iron, cobalt, and nickel complexes in homogeneous catalytic systems is introduced and summarized in detail. Finally, the challenges for the future development of homogeneous catalytic systems that utilize homodinuclear bimetallic iron complexes are outlined.

Key words: Homodinuclear complex, Homogeneous catalysis, Iron catalyst, Co catalyst, Ni catalyst