The nitrogen-donor ligand is one of the ligands. For nitrogen-donor ligands, the atoms, molecules and ions that bond with the central atom (metal or metalloid) should be included N atoms， and electron electrons are provided by N atom. With the rapid development of coordination chemistry, Coordination complex are widely used in many fields. Due to the wide variety of nitrogen-donor ligands and the formation of coordination chemistrys for different functional uses, the research and application of nitrogen donor ligands is increasing. Nitrogen-Donor ligandsFigure 1. Bisimine ligand Applications With the development of coordination chemistry, the application of nitrogen-donor ligands has become more widespread. Nitrogen-donor ligands are generally not used alone, but can be combined with a central atom to form a coordination complex that can be used in a variety of applications. Optical material: The metal coordination complex luminescent material using the nitrogen-donor ligand as a ligand is a kind of material which has both high fluorescence quantum efficiency and good stability, and therefore its future is widely favored. The coordination complexe of nitrogen-donor ligands with Cu(I) and rare earth metals have been well demonstrated in terms of luminescence. They can be used as ligands to synthesize metal-organic coordination complexe. The luminescent material provides a reference to improve or even solve the problems of poor solubility of the coordination complex and low quantum yield. In addition, they can also be used to develop electrochemical sensors by their interaction with DNA. Metal catalyst: .Due to the strong coordination ability of nitrogen-donor ligands for metal ions, it is widely used in the synthesis and research of transition metal catalysts. And because metal catalysts have good catalytic activity and selectivity, they are widely used in many types of organic synthesis reactions. For example, a bidentate nitrogen-donor ligand palladium coordination complex catalyzes a carbonylation reaction; and a tridentate nitrogen-donor ligand nail coordination complex can catalyze a hydrogen transfer reaction and or atom transfer radical polymerization reaction. Antibacterial agents: The development and application of antibacterial complexes in synthetic fibers and textiles is of great significance. Neutral nitrogen donor ligands and rare earths can form antibacterial coordination complexe, and have certain antibacterial effects against bacteria such as Pseudomonas aeruginosa and Neisseria gonorrhoeae. The use of the coordination complex in the finishing of the synthetic fiber gives the fabric a strong broad-spectrum antibacterial effect. Extraction separating agent: Due to the superiority of its own structure, nitrogen donor ligands can be completely incinerated after use, which can avoid the advantages of secondary solid contaminants at the end of service life. It can be used to separate radioactive lanthanides and actinides element.