Royal Society of Chemistry, Journal of Materials Chemistry C Materials for optical and electronic devices, 45(2), p. 9701-9711, 2014
DOI: 10.1039/c4tc01072h
Full text: Unavailable
The regular MCM-41 type mesostructured silica material was used as a support for the incorporation of the highly luminescent tris(beta-diketonate) complex Eu(tta)3ephen yielding the hybrid MCM-Eu material. Suitable characterization by powder X-ray diffraction (XRD), thermogravimetric analyses (TGA), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), 13C and 21Si solid state NMR spectroscopy and photoluminescence spectroscopy was accomplished. The combination of Ultraviolet-Visible spectroscopy (UV-Vis) and photoluminescence techniques shows that this incorporation seems to modify essentially the second Eu3+ coordination shell. For a material that has a simply impregnated lanthanide complex, the herein reported maximum 5D0 quantum yield (q) value of 0.31 is a significant high value, being almost in the same scale of the values obtained for the materials with covalently bonded complexes. A detailed theoretical photoluminescence study of the MCM-Eu with the recently developed Luminescence Package- LUMPAC is presented. The high accuracy of the theoretical calculations is achieved through the comparison with the experimental values. Aiming at a deeper understanding of the photoluminescence process, the ligand-to-Eu3+ intramolecular energy transfer and back–transfer rates were also predicted. The dominant pathway involves the energy transfer between the lowest energy ligand triplet and the 5D0 level (9.70 ×107 s-1).