A new β-diketone, 5,6-dimethoxy-2-(2,2,2-trifluoroethyl)-1-indone (5,6-DTFI) and two series of 5,6-DTFI lanthanide complexes, namely, Nd(5,6-DTFI)3(H2O)(CH3OH) (1), Nd(5,6-DTFI)3(phen) (2), Yb(5,6-DTFI)3(H2O)2 (3) and Yb(5,6-DTFI)3(phen) (4) (phen = 1,10-phenanthroline), have been isolated. X-ray diffraction analysis reveals that all complexes 1–3 have mononuclear structures. NIR luminescent spectra of complexes 1–4 show strong characteristic emissions of the corresponding Nd3+ and Yb3+ ions. Upon doping poly(methylmethacrylate) (PMMA) with complex 1 to form a film, the PMMA polymer matrix acts as a co-sensitizer for Nd3+ ion and increases the NIR luminescent lifetimes, overall quantum yields and the thermal stability in comparison with the precursor complex 1.
