CrIII and CuI complexes of 2,2′,2″-(1H-imidazole-2,4,5-triyl)-tripyridine: In situ generation of imidazole ring from the coupling of picolinaldehyde and ammonium acetate

• A ligand and two complexes were prepared by in situ metal–ligand reaction.
• The magnetic property of complex 1 was studied.
• The catalytic activity of complex 2 was investigated.

The syntheses, characterizations and properties of two coordination complexes, [Cr3(L)3Cl6] (1) and [Cu4(L)2Br2]n (2) (HL = 2,2′,2″-(1H-imidazole-2,4,5-triyl)tripyridine) were reported. The HL ligand was unprecedentedly afforded by metal-mediated solverthermal in situ metal–ligand reaction among picolinaldehyde, ammonium acetate and metal ions. Compound 1 can be described as a bottom-opened vase-like complex with the three CrIII ions showing a triangle conformation. For complex 2, the sandwich-like [Cu4(L)2]2 + moieties are linked by bromide ions to generate a 1D chain framework. Variable-temperature magnetic studies in the temperature range of 2.0–300 K for 1 reveal antiferromagnetic CrIII⋯CrIII interactions. The catalytic activity of 2 towards the reaction of 2-butanone and ethylene glycol was also investigated; it showed a very good catalytic property allowing for the easy and high yielding preparation of 2-ethyl-2-methyl-1,3-dioxolane under mild conditions.

Solvothermal in situ metal ligand reaction of picolinaldehyde, ammonium acetate and metal ions leads to generation of two structurally interesting coordination complexes supported by 2,2′,2″-(1H-imidazole-2,4,5-triyl)-tripyridine.Figure optionsDownload as PowerPoint slide