Number of donor-atom contacts a central metal atom has with its ligands. Common values are 4 (tetrahedral, square planar) and 6 (octahedral); large/lanthanide ions reach 8-12. Sets the geometry of the complex.
Coordination number
Related concepts
- Ligand
- Werner's theory of coordination compounds
- 18-electron rule
- Chelate effect (thermodynamic)
- Metal-organic frameworks (MOFs)
- Werner (1893, Nobel 1913)
- M-M bond (Cotton 1964)
- Hemoglobin (Perutz 1968)
- Z-scheme (Hill 1937)
- Nitrogenase (Burns 1965)
- Cytochrome (Warburg 1925)
- Ferritin (Laufberger 1937)
- Zn finger (Klug 1985)