Ternary lanthanide (Er3+, Nd3+, Yb3+, Sm3+, Pr3+) complex-functionalized mesoporous SBA-15 materials that emit in the near-infrared range

The ternary lanthanide complexes [Ln(hfth)3phen] (Ln = Er, Nd, Yb, Sm) and [Pr(tfnb)3phen] have been successfully covalently attached in the ordered SBA-15 mesoporous materials via a functionalized 1,10-phenanthroline group 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline (Phen-Si). The derivative materials [denoted as Ln(hfth)3phen–S15 and Pr(tfnb)3phen–S15; Ln = Er, Yb, Nd, Sm; hfth = 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dionate; tfnb = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionate] were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption/desorption. The fluorescence spectra and luminescence lifetimes of these lanthanide-complex-functionalized materials were also recorded. After ligand-mediated excitation, the emission spectra of the Ln(hfth)3phen–S15 and Pr(tfnb)3phen–S15 materials all display the characteristic NIR luminescence of the corresponding lanthanide ions through the intramolecular energy transfer from the ligands to the lanthanide ions. With these lanthanide-complex-functionalized materials, the luminescent spectral region from 1300 to 1600 nm, which is of particular interest for telecommunication applications, can be covered completely.