Syntheses, structures, and properties of four Cu(II) complexes containing 2-(1H-imidazol-1-methyl)-1H-benzimidazole ligand

Abstract

Four Cu(II)-containing complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole (imb), [Cu₂(imb)₂Cl₄] · 2CH₃OH (1), {[Cu(imb)(bdic²⁻)] · 1.5H₂O · DMF} _n (2), {[Cu(imb)(bdic²⁻)] · 2H₂O} _n (3), and {[Cu₃(imb)₂(Hbdc³⁻)₂] · 2H₂O} _n (4), where H₂bdic = 1,3-benzenedicarboxylic acid and H₄bdc = 1,2,4,5-benzenetetracarboxylic acid, have been synthesized and characterized by single-crystal diffraction. Dinuclear 1 is isolated by the reaction of imb with CuCl₂ · 2H₂O. When H₂bdic is added in the reaction with the other experimental conditions unchanged, 2 with a different structure is obtained. The [Cu₂(imb)₂] dinuclear units are linked through bdic²⁻ groups to form a 2-D structure. The imb reacts with CuCl₂ · 2H₂O and H₂bdic at 80°C to give 3, which exhibits a 2-D (4,4) network. With the replacement of H₂bdic with H₄bdc in the above reaction, 4 is formed featuring a 2-D structure in which Hbdc³⁻ is a six-connecting group. Their IR spectra and thermogravimetric analyses are also investigated.

Keywords:

• Copper complex
• 2-(1H-imidazol-1-methyl)-1H-benzimidazole
• Crystal structure
• Thermogravimetric analysis

Acknowledgments

We gratefully acknowledge the financial support by the Program for Science & Technology Innovation Talents in Henan College of Chinese Medicine and the Education Department of He’nan Province (2009A150029).