Synthesis of copper–zinc bimetallic imidazolate framework compounds and the structure of Cu(I)-containing Cu2Zn(N2C3H3)4

Copper(II)–zinc(II) bimetallic imidazolate metal–organic framework compounds of composition Cua Znb Im2(a + b ) (Im = C3H3N2), including Cu2ZnIm6 (1), were prepared in high yields from the metal oxides under mild aqueous conditions using a novel acid catalysis method. Mild acidic hydrothermal treatment of paramagnetic 1 (≥120 °C) gave diamagnetic Cu(I)-containing Cu2ZnIm4 (2) in high yield. The formation mechanism of 2 involves electron transfer from Im− to Cu(II), with concomitant formation of the unusual cyclotriimidazole, C9H6N6. Air-stable 2, characterized by single-crystal X-ray diffraction, crystallized in the tetragonal space group View the MathML sourceP4¯21c, with a = b = 10.9623(3), c = 6.3231(4) Å, α = β = γ = 90°, V = 759.86(6) Å3, and Z = 1.