Synthesis and Characterization of PVP/Tb4/3L•7H2O Luminescent Complex

Abstract

Rare earth terbium [Tb (III)]-pyromellitic acid [H4L] luminescent complex has been synthesized in polyvinylpyrrolidone (PVP) matrix by precipitation method. The chemical constitution of the complex has been demonstrated as PVP/Tb4/3L•7H2O by a combination of elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Fourier-transform infrared spectroscopy (FT-IR). X-ray diffraction analysis (XRD) has shown that the complex is a new kind of crystal whose structure is totally different from the ligand. The morphology of the complex has been investigated by scanning electron microscopy (SEM). The results have shown that the well dispersed complex has a bulk crystal structure and the diameter of the crystal is about 1-2 μm. Thermogravimetric analysis (TG) has indicated that the luminescent complex is thermally stable below 467 °C. Photoluminescence spectra (PL) have revealed that the complex can emit Tb3+ characteristic green fluorescence under ultraviolet excitation.