Résumé
Urea-based bis-silylated bipyridine (bpy) organic–inorganic hybrids incorporating different lanthanide (Ln3+) ions (Eu3+, Gd3+, Tb3+ or Eu3+/Tb3+) were obtained by the sol–gel process. The structure and the emission characteristics of the hybrids were ascertained using X-ray diffraction, nuclear magnetic resonance, Fourier transform infrared spectroscopy, photoluminescence, and quantum yield measurements. The hybrids feature both the emission of the host and the Eu 3+ and/or Tb3+ transitions allowing a fine-tuning of the color from the blue to the red, orange, or green spectral regions. Bpy-to-Ln3+ and Tb3+-to-Eu3+ energy transfer mechanisms are demonstrated and the hybrids present slightly distinct Ln3+ coordination spheres due to the different bpy/Ln3+ ratios.