Thin Films of Highly Luminescent Lanthanide Complexes Covalently Linked to an Organic−Inorganic Hybrid Material via 2-Substituted Imidazo[4,5-f]-1,10-phenanthroline Groups

A homogeneous distribution of luminescent lanthanide(III) 2-thenoyltrifluoroacetonate complexes (Ln = Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb) in an organic−inorganic hybrid material was obtained by grafting the complexes to the solid matrix via 2-substituted imidazo[4,5- f ]-1,10-phenanthroline moieties. Thin films of the silica hybrid material were prepared by the sol−gel method and by spin-coating of the gelating solution on glass slides or on oxidized silicon wafers. The thickness of the thin films was determined by scanning electron microscopy (SEM). High-resolution luminescence spectra of the lanthanide complexes were recorded, and the luminescence decay times were measured. The luminescence quantum yields of europium(III)-doped thin films exposed to different drying conditions were determined by using an integrating sphere.