Cadmium coordination polymers based on biimidazole and bibenzimidazole:Syntheses, crystal structures and fluorescent properties

摘要

Three new CdII complexes with two analogous ligands of 2,2′-biimidazole (H_2biim) and 2,2′-bibenzimidazole (H_2bbim), have been synthesized and characterized by elemental analyses, IR spectroscopy as well as single crystal X-ray diffraction. The results reveal that the structures of the complexes range from onedimensional (1D) chains in [Cd(H_2biim)(N_3)_2]n (1) to two-dimensional (2D) layer in [Cd(bbim)_(0.5)(Hbbim)]n (2) and three-dimensional (3D) network in [Cd_3(biim)_2(Hbiim)(N_3)]n (3), with various modes of these ligands, which is tuned by different polarity of solvents and pH values. The fluorescent spectra of these complexes and ligands have been also investigated in the solid state at room temperature.