ligandy

Ligandy is a term encountered in some chemical and materials science discussions to denote a class of binding agents that coordinate to metal centers. It is not an established formal term in coordination chemistry; the standard term is ligand. In practice, ligandy can refer to organic molecules, organometallic complexes, or polymeric or surface-bound species designed to bind metals through one or more donor atoms such as nitrogen, oxygen, sulfur, or phosphorus.

Chemists categorize ligands by denticity (monodentate, bidentate, polydentate) and by mode (neutral versus anionic). Ligand frameworks described under the ligandy concept include simple amines and phosphines, as well as macrocyclic and polymeric ligands, which can be engineered to tune binding strength, stereochemistry, and reactivity. Surface-immobilized ligands on nanoparticles, porous materials (such as metal-organic frameworks), or resins are common ligandy implementations for heterogeneous catalysis and separations.

Applications of ligandy concepts include catalysis (such as cross-coupling and hydrogenation), metal ion sequestration and extraction, chemical sensing, and drug delivery where metal coordination plays a role. In research communication, ligandy is sometimes used informally to emphasize the ligand character of a system or to distinguish ligand-based design from the metal center itself.

See also: ligand, coordination chemistry, metal–ligand bonding, chelation, metal-organic framework, polymer ligand.