metalimidazolate

Metalimidazolate is a term used to describe metal–imidazolate motifs in coordination chemistry, referring to assemblies in which imidazole-based ligands, typically in their deprotonated imidazolate form, coordinate to metal centers to build extended networks. This motif is central to metallimidazolate frameworks, a class that includes zeolitic imidazolate frameworks (ZIFs). The imidazolate ligand provides nitrogen donors capable of strong binding to metal ions, enabling robust and often porous structures.

Structural features commonly include the μ2-bridging mode, where a single imidazolate connects two neighboring metal centers, linking metal nodes into two-dimensional layers or three-dimensional frameworks. The resulting metal–nitrogen bonds and the aromatic imidazole ring contribute to framework stability, chemical resistance, and predictable connectivity that define the material’s topology.

Synthesis typically involves combining metal salts with imidazole or substituted imidazoles under solvothermal or hydrothermal conditions, with base present to generate the imidazolate. Metals such as zinc and cobalt are frequently used, though a wide range of transition metals can participate. The resulting metallimidazolate frameworks exhibit tunable porosity and high surface areas, making them attractive for gas storage, separations, catalysis, and sensing.

See also: Imidazolate, Zeolitic imidazolate framework, Metal–organic framework, Coordination polymer.