Luminescence properties of Eu3+β-diketonates incorporated in cubic mesoporous silica

Luminescent materials have been prepared by wet impregnation of Europium (III) dibenzoylmethane complexes in either non-silylated or silylated mesoporous MCM-48 silica. Silylation and incorporation of the Eu (III) complex were confirmed by Nuclear Magnetic Resonance, N2-sorption, X-ray diffraction and Infrared spectroscopy. The luminescence properties were investigated at room and high temperatures up to 200 °C. Information on host-guest interactions were collected by analyzing the optical characteristics of the Eu (III) ions in the different media. In particular, the intensity parameter Ω2 is confirmed to be a useful spectroscopic probe for Eu (III) first coordination shell interaction. The role of the O2−-Eu3+ charge transfer band and the impact of the silylation on the luminescence properties at room and high temperatures is demonstrated.