Transition metal imidazole complex

In contrast, imidazole derivatives, especially histidine, are pervasive ligands in biology where they bind metal cofactors.

Homoleptic octahedral complexes have been characterized by X-ray crystallography for the following dications: Fe2+, Co2+, Ni2+, Zn2+, Cd2+.

The imidazole side chain of histidine residues in proteins are common binding sites for metal ions.

Unlike the free amino acid, the histidine residue (i.e., as a component of a peptide or protein), coordinates solely via the imidazole substituent.

The concept relies on the affinity of the imidazole side chain for metal cations.

One example of an imidazolate complex from biochemistry is found at the active site of copper-containing superoxide dismutase.

The M2(μ-imidazolate) motif underpins materials comprising zeolitic imidazolate frameworks ("ZIF"s).

Structure of the histidine complex [Ni(κ 3 -histidinate) 2 ] 2- . [ 1 ]
A "picket-fence porphyrin" complex of Fe, with axial coordination sites occupied by methylimidazole (green) and dioxygen . This synthetic complex mimics aspects of myoglobin.
Structure of vitamin b12 , illustrating the dimethylbenzimidazole ligand
Structure of am imidazolate-bridged tricopper complex. [ 9 ]