Syntheses and structural characterization of inorganic–organic hybrid solids of bis-imidazolium chlorocadmate complexes

Abstract

Six organic–inorganic complexes derived from bis-imidazole derivatives ([(H₂L1)(CdCl₃ ⋅ H₂O)₂] (1), L1 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole; [(H₂L2)CdCl₄] (2), L2 = 1,1′-bis(benzimidazolyl)methane; [(H₂L3)CdCl₄] (3), L3 = 1-(2-(1H-benzimidazol-1-yl)ethyl)-1H-benzimidazole; [(H₂L4)₄(CdCl₄)₄] ⋅ 13H₂O (4), L4 = 1,5-bis(1-benzimidazolyl)-3-oxapentane; [(H₂L5)CdCl₄] (5), L5 = 1-(4-(1H-benzimidazol-1-yl)butyl)-1H-benzimidazole; [(H₂L6)(Cd₂Cl₈)_0.5] ⋅ H₂O (6), L6 = 3,6-bis(imidazol-1-yl)pyridazine), and cadmium(II) chloride dihydrate were prepared and characterized by IR, X-ray structure analysis, elemental analysis, and TG analysis. The imidazolyl moieties in all six compounds are essentially planar. X-ray diffraction analysis revealed that complexes 1–6 have 3-D network structures built from hydrogen bonds between imidazolium cations, chlorocadmate anions, and water. The arrangements of the anions and cations in their solid state are dominated not only by the size and symmetry of the imidazolium cations, but also by the different structure types of the chlorocadmate anions as well as the hydrogen-bonded interactions existing in the crystal structures. All of the complexes are thermally stable.

Keywords:

• Cadmium
• Imidazolium
• Crystal structure
• Inorganic-organic hybrid

Acknowledgment

We gratefully acknowledge the financial support of the Education Office Foundation of Zhejiang Province (project No. Y201017321) and the financial support of the Zhejiang Forestry University Science Foundation.