monodentaat

Monodentaat is the Dutch term for a monodentate ligand in coordination chemistry. In English, a monodentate ligand is a molecule or an ion that donates a single lone pair of electrons to a central metal atom or ion through one donor atom. The donor atom is typically oxygen, nitrogen, sulfur, or carbon, and the ligand binds at one site only.

Common examples of monodentate ligands include water (H2O), ammonia (NH3), chloride (Cl−), cyanide (CN−), fluoride (F−), and carbon monoxide (CO). These ligands can create a range of coordination geometries around the metal, such as octahedral arrangements with six identical monodentate ligands or square planar arrangements with four. The overall geometry depends on the metal’s oxidation state, size, and the nature of the ligands.

Monodentate ligands are contrasted with bidentate, tridentate, and other multidentate (or polydentate) ligands, which supply two or more donor atoms and can form chelate rings with the metal. The chelate effect often stabilizes complexes formed with polydentate ligands due to entropic advantages, whereas monodentate ligands do not benefit from chelation. Some ligands can be ambidentate, capable of binding through different donor atoms, but still act as monodentate in a given coordination mode.

In summary, monodentaat describes ligands that bind through a single donor site, playing a fundamental role in defining the structure and reactivity of many coordination compounds.