Improvement of emission intensity in luminescent materials based on the antenna effect

Ternary Eu(III) complexes with macrobicyclic and acyclic ligands+co-ligands were encapsulated in silica or methylated silicate xerogels. Additionally, deuterated reagent and solvent were used in the sol-gel procedure. This preparation method with moderate thermal treatment reduced the concentration of OH groups in the materials and simultaneously improved their photophysical properties, i.e. increased luminescence intensity and prolonged luminescence lifetime. The best results were obtained for the Eu(III) complex with a cryptand of the [biqO(2).2.2]+1,10-phenanthroline type (where biqO(2)=3,3'-biisoquinoline-2,2'-dioxide) immobilized in methyl-modified silicate xerogel. The effective luminescence properties of this sample make it a promising candidate for use as a luminescent material. (C) 2000 Elsevier Science S.A. All rights reserved.