Synthesis, crystal structure, electrochemiluminescence property of a novel cadmium (II) coordination polymer possessing 4-cyanopyrazole

Abstract

A novel one-dimensional cadmium (II) coordination polymer [Cd(HL)2(μ-Cl)2]n (1) (HL = 4-cyanopyrazole) was obtained using a slow evaporation skill at room temperature and characterized by single crystal X-ray diffraction analysis, powder X-ray diffraction (PXRD), elemental analysis, infrared spectroscopy (IR) and thermogravimetric analysis (TGA). The data of the single X-ray diffraction displayed that 1 crystallized in the triclinic system, P-1 space group. In the solid state, two HL acted as terminal ligands, bound to Cd(II) center formed [Cd(HL)2]2+ unit, which was then linked by two Cl− anions to generate a straight one-dimensional chain structure. Then, a two-dimensional layer structure was obtained by wide-ranging N-H⋯Cl intermolecular hydrogen bonds. Moreover, the solid state fluorescent property of the polymer was examined and compared with the ligand. Additionally, Hirshfeld surface analysis of the polymer 1 was further investigated for the intermolecular interactions. The result indicated that the main intermolecular contact was N⋯H/H⋯N interaction with the proportion of 24.8% in the 2D fingerprint plot. Significantly, the polymer 1 proved excellent electrochemiluminescence (ECL) property in PBS solution.