Synthesis, Crystal Structure, and Properties of a New Coordination Polymer Built from N/O-Donor Mixed Ligands

Abstract

The coordination polymer, namely, [Cd(H 2 L)(nobda)] n (1) was prepared by the reaction of Cd(NO 3 ) 2 ·4H 2 O with 4-amino-1,2-benzenedicarboxylic acid (H 2 nobda) and 1,4-di(1H-imidazol-4-yl)benzene (H 2 L), and characterized by single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, thermogravimetric analysis, and powder X-ray diffraction (PXRD). The carboxylic acid of H 2 nobda ligands was completely deprotonated to be nobda 2− anions, which act as tridentate ligand to connect the Cd 2+ to form two-dimensional (2D) network, while the neutral H 2 L ligands serve as a linear didentate bridge to connect two adjacent Cd 2+ ions upper and down the 2D layer. The adjacent 2D layers were further linked into the three-dimensional (3D) supramolecular polymer by the weak interactions such as hydrogen bonds and π−π stacking interactions. The ultraviolet-visible (UV-vis) absorption spectra and luminescent properties in the solid state at room temperature have been investigated.