Dinitrogen Activation and Transformation Promoted by Rare Earth and Actinide Complexes

Dinitrogen gas is highly chemically inert, and the activation and transformation of dinitrogen are challenging. Nitrogen-containing organic compounds have extensive and important applications in developing the national economy. It is of great scientific and economic significance to realize the direct conversion from dinitrogen to nitrogen-containing organic compounds under mild conditions. The activation and transformation of dinitrogen via metal-nitrogen complexes are one of the research hotspots, and chemists have made significant achievements in this field during the past decades. The current research on the activation and transformation of dinitrogen mainly focuses on the main group and transition metal complexes. In contrast, the research on rare earth (RE) and actinide (An) metal-nitrogen complexes is relatively less. Although nearly one hundred crystal structures of rare earth and actinide metal-dinitrogen complexes have been reported, the vast majority of them cannot undergo further nitrogen derivatization reactions, and the types of the supporting ligands are still limited. However, due to the unique electronic structures, f-block complexes can exhibit unusual reactivity different from the main group and transition metals. For example, the f-block metals do not necessarily have to stay in a low oxidation state to activate the dinitrogen, which may lead to the discovery of new dinitrogen transformation modes. As China is rich in rare earth and thorium resources, it is vital to carry out research on dinitrogen fixation and transformation based on rare earth metals and actinides. The synthesis of rare earth and actinide dinitrogen complexes over the past five years, as well as the progress on the generation of nitrogen-containing organic compounds from dinitrogen gas promoted by rare earth and actinide complexes were summarized in this review.