Synthesis and Luminescence Properties of Monophasic Organic−Inorganic Hybrid Materials Incorporating Europium(III)

Phosphine oxides 1 − 5 bearing one, two, or three hydrolyzable Si(OR) 3 groups have been prepared. They were treated with anhydrous europium salts [Eu(NO 3 ) 3 or EuCl 3 ] to afford complexes 6 − 10, the stoichiometry of which was found to be one Eu 3+ for three P O centers. The hydrolytic polycondensation of these complexes gave rise to nanostructured hybrid materials incorporating Eu 3+ . A solid-state 31 P NMR study of these hybrid materials has shown that Eu 3+ remains well encapsulated within the materials when they are prepared from europium complexes with phosphine oxides bearing one hydrolyzable Si(OR) 3 group. The luminescence behavior of these materials has been investigated. At room temperature, a very strong red emission was observed. The study of the emission lines at 2 K strongly suggested that there was predominantly one Eu 3+ binding site within the materials.