Synthesis, Crystal Structures, and Properties of a New Supramolecular Polymer Based on Mixed Imidazole and Carboxylate Ligands

Abstract

One new coordination polymer, namely, [Cd3(H2L)3(Pza)2(H2O)2]n (1) was synthesized by the reaction of Cd(NO3)2·4H2O with 1,4-di(1H-imidazol-4-yl)benzene (H2L) and 3,5-pyrazoledicarboxylic acid (H3pza) and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, and powder X-ray diffraction (PXRD). The H3pza ligand was completely deprotonated to pza3−, which bridged the Cd2+ to form one-dimensional (1D) chain. The adjacent 1D chains were further linked into the two-dimensional (2D) layer by the linear H2L ligands. The weak interaction, including hydrogen bonds and π−π stacking interactions, extends the 2D layers into three-dimensional (3D) supramolecular polymer. Complex 1 shows intense light blue emission in the solid state at room temperature.

Keywords

• coordination polymer
• 2D layer structure
• structural characterization