ligandens

Liganden is the Swedish plural term for ligand, while ligandens is the possessive form used to indicate something belonging to a ligand. In chemistry, a ligand is a molecule or ion that binds to a central atom or ion, typically a metal, to form a coordination complex. The binding usually occurs through one or more atom with lone pairs that donate electron density to the metal.

Ligands can be neutral or charged and are characterized by their denticity, i.e., the number of donor atoms that attach to the metal. Monodentate ligands bind through a single donor atom, while polydentate ligands bind through multiple atoms and can form chelate rings, often leading to higher complex stability due to the chelate effect. Common donor atoms include nitrogen, oxygen, sulfur, phosphorus, and sometimes halogens. Coordination numbers in complexes commonly range from four to six, yielding geometries such as tetrahedral, square planar, and octahedral.

Ligand behavior is described by theories such as crystal field theory and ligand field theory, which relate ligand properties to the splitting of d-orbital energies in the central metal. Concepts such as hard and soft acids and bases help predict binding preferences. Ligands also influence the reactivity, color, and magnetic properties of complexes, with applications in catalysis, bioinorganic chemistry, materials science, and medical imaging.

Examples of ligands include water, ammonia, cyanide, carbon monoxide, ethylenediamine (en), and oxalate. The study of ligands and their complexes provides a foundational framework for understanding coordination chemistry and its diverse applications.