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
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.
References


![Imidazolate: In the human SOD1 enzyme (N-terminus = blue, C-terminus = red), the copper (orange sphere) and zinc (grey one) are bridged by imidazolate.[3]](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1c/2c9v_CuZn_rib_n_site.png/500px-2c9v_CuZn_rib_n_site.png?utm_source=en.wikipedia.org&utm_campaign=parser&utm_content=thumbnail)
