Fabrication and luminescent properties of Eu(BMPPA)3BPy complex and its functionalized silica nanocomposites

Abstract Luminescent silica nanocomposites functionalized with a Eu-complex have been prepared and characterized. The europium complex is composed of 2,2′-bipyridyl (BPy) and 2-(4-bromomethyl)phenylpropionic acid (BMPPA), which contains highly active benzyl bromide substituents and can covalently bind with poly(4-vinylpyridine) (P4VP)-modified silica nanoparticles (nanoSiO 2 P4VP) to form nanoSiO 2 P4VPEuBPy composites. Microscopic images revealed that the nanoSiO 2 P4VPEuBPy composites easily formed aggregates, due to an inter-particle binding caused by the benzyl bromide among the composites. The as-prepared nanocomposites showed the typical emissions of Eu(III) ions at the wavelengths from 580 nm to 750 nm designated to the 5 D 0  →  7 F n transitions. Time-resolved fluorescence decay measurements revealed that the emission lifetime was approximately 0.204 ms and 0.576 ms for the nanoSiO 2 EuBPy composites, a little shorter than that in the Eu(BMPPA) 3 BPy complex.