Central Metal Atom
The metal atom or ion at the heart of a coordination entity, which accepts electron pairs from the ligands.
Unit
Dimensionless
In depth
The central metal is a Lewis acid with vacant orbitals of suitable energy, which is why transition metals with their accessible d orbitals dominate coordination chemistry. Its identity, oxidation state and size determine the coordination number, geometry and stability of the complex.
Examples in the real world
Cobalt in [Co(NH₃)₆]³⁺; iron in haemoglobin; magnesium at the centre of chlorophyll.