Synthesis (in situ) on organofunctionalized silica and spectroscopic study of Eu(III) complexes

Abstract The complexes [Eu(eta) 2 ·(H 2 O) 4 ]Cl and [Eu(eta) 2 ·(phen)·(H 2 O) 2 ]Cl (eta = Etil 4,4,4-trifluoroacetoacetate; phen = 1,10-phenanthroline) are synthesized and characterized. The complexes are also synthesized in situ on organofunctionalized silica surfaces. It is verified that the substitution of water molecules by a phen molecule into the coordination sphere of a Eu-eta complex enhances the emission intensity due to the lowering of the number of OH oscillators which suppress the luminescence. Furthermore, the prepared in situ eta-organofunctionalized silica complex exhibits an optimisation of their optical properties, in comparison with the “free” complex, mainly a remarkable (about 26 times) enhancement of the emission intensity. The obtained experimental parameters show that the dynamic coupling mechanism is predominant.