Structural and fluorescent characterizations of one- and two-dimensional Cd(II) metal-organic frameworks

Benzimidazole-5-carboxylate (HL1) and 5-methylbenzimidazole-6-carboxylic acid (HL2) have been employed to assemble with Cd(II) ions under hydrothermal conditions, leading to the generation of 1D (1) and 2D (2) metal-organic frameworks. The two coordinated water molecules of cadmium in 1 restrain the carboxylic moiety from adopting a bidentate chelating coordination mode, which seems to be an important factor in the dramatic structural change from 1D to 2D. Both complexes display blue emission in the solid state and the luminescent properties relate to their structures.