Abstract
The preparation of coordination polymers with good room temperature phosphorescence is the focus of current research. In this paper, zinc and cadmium were used as metal ions and 2,3-pyridinedicarboxylic acid (2,3-H2pydc = 2,3-pyridinedicarboxylic acid) as organic ligands to successfully synthesize Cd(II) homo- and Zn(II)Cd(II) heterometallic coordination polymers microstructures. In addition, morphology, powder X-ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and their luminescence properties were studied. Cd-CP is a micron-sized spherical structure, while Zn/Cd-CP is a flower-like structure formed by the accumulation of sheets. The results show that Cd(II) homo- and Zn(II)Cd(II) heterometallic coordination polymers have quantum yields of 10.05% and 8.54%, respectively. It is worth noting that the lifetime of Cd-CP is 124.62 ms, while the lifetime of Zn/Cd-CP is significantly extended to 363.09 ms after doping with metal ion Zn2+. The phosphorescent lifetime of coordination polymers was improved by the heterometallic doping strategy, which provided a new idea and method for the preparation of coordination polymers with long-lived room temperature phosphorescent properties. In addition, the two coordination polymers exhibited blue and cyan fluorescence at 365 nm UV light, respectively, and a green afterglow of about 2 seconds could be observed with the naked eye when the UV lamp was turned off.