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 pr eparation method with moderate thermal treatment reduced the concentration of OH groups in the materials and simultaneously improved their photophysic al properties, i.e. increased luminescence intensity and prolonged luminesc ence 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 xero gel. The effective luminescence properties of this sample make it a promisi ng candidate for use as a luminescent material. (C) 2000 Elsevier Science S .A. All rights reserved.