Facile synthesis and characterization of macromolecular Eu(III) complexes with β-diketone ligands and poly(4-vinyl pyridine-co-methyl methacrylate)

Abstract

Poly(4-vinyl pyridine-co-methyl methacrylate), PVM, was synthesized by radical copolymerization of 4-vinyl pyridine with methyl methacrylate. Afterward, the macromolecular Eu(III) complexes of general formula [Eu(β-diketonate)3(PVM)(H2O)], where β-diketonate = benzoylacetonate (BA), 1; dibenzoylmethanate (DBM), 2; thenoyltrifluoroacetonate (TTA), 3, were prepared and fully characterized by means of element analysis, thermal analysis, SEM, 1H NMR, 13C NMR, FT-IR, and UV-vis spectra. The macromolecular complexes can dissolve in many ordinary organic solvents (e.g. dimethylformamide, dimethylsulfoxide, and tetrahydrofuran), as well as emit strong red luminescence under ultraviolet light excitation. The room-temperature 5D0 lifetime and fluorescence quantum yield of 3 are 391 μs and 37%, respectively, which are far more than those of 1 (194 μs, 16%), 2 (160 μs, 18%), and Eu(TTA)3(H2O)2 (224 μs, 22%). The CIE coordinates of 1–3 are calculated as (0.49, 0.33), (0.62, 0.33) and (0.65, 0.34), respectively, demonstrating the promising utilization future of these complexes, especially the latter two, as luminescent functional materials used in large-area optical display.