Luminescent properties of a new Nd³⁺-doped complex with two different carboxylic acids and pyridine derivative

A new Nd³⁺-doped organic complex featuring two different perfluorinated carboxylic acids as the first ligand and pyridine derivative 2-amino-3-chloro-5-(trifluoromethyl)pyridine as the second ligand was designed and synthesized. Successful coordination between the ligands and central rare earth ions was confirmed by Fourier transform infrared spectroscopy (FT-IR) spectra, ¹H nuclear magnetic resonance (¹H NMR) spectra, and UV spectra, and the synthesized complex is inferred to be eight-coordinate structure. Solution of the complex dissolved in DMSO-d6 was prepared and then its fluorescence spectrum, UV–Vis–NIR absorption spectrum, and fluorescence decay curve were tested. The fluorescent lifetime is about 7 μs. Based on the above experimental research, Judd–Ofelt analysis was carried out, and the results indicate that appropriate coordination environment around Nd³⁺ in this solution results in a high fluorescent quantum efficiency 2 % and a large stimulated emission cross-section about 3.2 × 10⁻²⁰ cm² at 1,064 nm.