Synthesis, structure, and photoluminescent property of a trinuclear CdII complex based on semi-rigid bis(imidazole-4,5-dicarboxylate) ligand

A new 3D complex, {[Cd3(HL)2(H2L)(H2O)4]·2H2O}n (1) (H4L = 1,1′-(1,4-phenylenebis(methylene))bis(1H-imidazole-4,5-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analyses, IR, TG, and X-ray single-crystal diffraction. Complex 1 is the first framework based on CdII ion and semi-rigid bis-IDC ligand. The (6,6)-net architecture of 1 is built from H2L2 − ligands linking 1D chain-like [Cd3(HL)2]n SBUs, which formed by HL3 − anions bridging two kinds of metal centers. In addition, complex 1 was demonstrated to display strong blue-violet fluorescence emission in the solid state at room temperature.