Imidazolate (C3H3N− 2) is the conjugate base of imidazole. It is a nucleophile and a strong base. The free anion has C2v symmetry. Imidazole has a pKa of 14.05, so the deprotonation of imidazole (C3H3N2H) requires a strong base.

Occurrence

In the human SOD1 enzyme (N-terminus = blue, C-terminus = red), the copper (orange sphere) and zinc (grey one) are bridged by imidazolate.

Imidazolate is a common bridging ligand in coordination chemistry. In the zeolitic imidazolate frameworks, the metals are interconnected via imidazolates. In the enzyme superoxide dismutase, imidazolate links copper and zinc centers.