A metal complex is a chemical structure formed when a metal ion bonds with one or more molecules or ions, known as ligands. These ligands can be simple ions, like chloride or nitrate, or larger molecules, such as ammonia or ethylenediamine. The metal ion typically has a positive charge and can coordinate with the ligands through electron donation, creating a stable arrangement. Metal complexes are important in various fields, including catalysis, biochemistry, and materials science. They play crucial roles in processes like enzyme function and industrial reactions. Understanding metal complexes helps scientists design new materials and improve chemical reactions.