metalcoordinated

Metalcoordinated is an adjective used in chemistry to describe species in which a metal ion is bound by ligands through coordinate covalent bonds. In coordination chemistry, ligands donate lone pairs to a metal center, forming a coordination complex. The arrangement around the metal is described by the coordination number and geometry, commonly octahedral, tetrahedral, or square planar. Ligands may be monodentate or multidentate (chelating); multidentate ligands often enhance stability, a phenomenon known as the chelate effect. Binding strength and geometry depend on the metal’s oxidation state, electronic configuration, and the hard/soft character of the interacting partners.

Representative inorganic complexes include [Fe(CN)6]3−, [Cu(NH3)4]2+, and [Ni(en)3]2+ (en = ethylenediamine). Beyond discrete complexes, metal-coordinated frameworks such as metal–organic frameworks (MOFs) form extended networks in which metal nodes are connected by organic ligands, yielding porous materials with applications in catalysis, gas storage, and sensing.

In biology and medicine, metal coordination is central to metalloproteins and metalloenzymes, where metal ions such as Fe, Zn, or Cu enable catalytic activity or structural stabilization. The concept, rooted in early Wernerian chemistry, remains foundational to inorganic and organometallic science and to the design of functional materials.