Efficient luminescent materials made by incorporation of terbium(III) and 2,2-bipyridine in silica/poly(ethylene oxide) hybrid gels

Silica/poly(ethylene oxide) hybrid gels have been prepared by the sol-gel m ethod using a precursor synthesized by reacting 3-isocyanotriethoxysilane w ith O,O'bis(2-aminopropyI)-poly(ethylene oxide). The hybrid gels were conse cutively swelled in ethanolic solutions first of terbium nitrate and then o f 2,2-bipyridine and in this manner they absorbed important amounts of both lanthanide ions and the ligand. The result was an efficient luminescent ma terial producing bright green luminescence by UV excitation. The ligand the n acts as an antenna for the exciting radiation which is transferred to the lanthanide emitter. The hybrid material can also yield blue luminescence b y itself, which is much enhanced in the presence of terbium ions. (C) 1999 Elsevier Science B.V. All rights reserved.