Imidazolate

Imidazolate

Names
IUPAC name Imidazolate
Other names Imidazolide
Identifiers
CAS Number	36954-03-7
3D model (JSmol)	Interactive image Interactive image
ChemSpider	2631931
ECHA InfoCard
E number
PubChem CID	4605971 Na salt 12796790 K salt 15977602 Zn salt 129690082 Cu salt
CompTox Dashboard (EPA)	{{#property:P3117}}
InChI InChI=1S/C3H4N2/c1-2-5-3-4-1/h1-4H/q-1 Key: LFLLXPLNBAQRCY-UHFFFAOYSA-N InChI=1S/C3H3N2/c1-2-5-3-4-1/h1-3H/q-1 Key: JBFYUZGYRGXSFL-UHFFFAOYSA-N
SMILES c1cnc[n-]1 c1c[n-]cn1
Properties
Chemical formula	C3H3N2−
Molar mass	67.070 g/mol
Acidity (pKa)	14.05
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	67.8 kJ·mol−1 (16.2 kcal·mol−1) Gas phase.
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Imidazolate (C₃H₃N⁻
₂) is the conjugate base of imidazole. It is a nucleophile and a strong base. The free anion has C_2v symmetry. Imidazole has a pK_a of 14.05, so the deprotonation of imidazole (C₃H₃N₂H) requires a strong base.

Occurrence

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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.