Acid-catalyzed synthesis of zinc imidazolates and related bimetallic metal-organic framework compounds

A convenient method involving acid catalysis is described for the preparation of zinc imidazolate metal organic framework compounds of the type ZnIm 2 (Im = imidazolate,1,3-N 2 C 3 H 3 ) and C-substituted derivatives, including 2-Me-, 2-Et- and benzimidazolates. This method also applies to synthesis of analogous copper and cobalt imidazolates, copper–zinc bimetallic imidazolates, (Cu a Zn b Im 2(a+b) ), heterometal-doped zinc imidazolates (M x Zn (1–x) Im 2 ), and multimetallic imidazolates. An unusual copper(1)-containing crystalline bimetallic imidazolate framework compound Cu 2 ZnIm 4 was prepared in high yield and structurally characterized (P42 1 c, a = b = 10.9623 (3), c = 6.3231 (4) Å, α = β = γ = 90°, V = 759.86 (6) Å 3 , Z = 2). Crystal structure redeterminations were also made for tetragonal zinc imidazolate framework solid and monomeric zinc diimidazole diacetate.