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

A novel one-dimensional cadmium (II) coordination polymer [Cd(HL)2(mu-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 center dot center dot center dot 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 center dot center dot center dot H/H center dot center dot center dot 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.