Ligand is a chemical term that refers to atoms, molecules, and ions that can bond with the central atom (metal or metalloid). In general, ligands provide at least one electron when participating in bonding. A compound consisting of a central atom and a ligand is called a complex.
Ligands have many functions. From the most basic physical properties, organic ligands can enhance the solubility of metal catalysts in organic solvents. From the structure of complexes, ligands can adjust the electrical properties of metal centers, thus changing their catalytic activity. According to the latest research, many ligands can adjust the catalytic activity of the catalytic system, which is conducive to the reaction. Of course, many chiral ligands, such as amino acids, It can provide the required chiral environment. Therefore, how to choose ligands is very important in the fields of bioinorganic chemistry, pharmaceutical chemistry, homogeneous catalysis, and environmental chemistry.