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.