Syntheses, Structures and Near-IR Luminescent Studies on Ternary Lanthanide (ErIII, HoIII, YbIII, NdIII) Complexes Containing 4,4,5,5,6,6,6-Heptafluoro-1-(2-thienyl)hexane-1,3-dionate

The ligand Hhfth [4,4,5,5,6,6,6‐heptafluoro‐1‐(2‐thienyl)hexane‐1,3‐dione], which contains a heptafluoropropyl group, has been used to synthesize several new ternary lanthanide complexes (Ln = Er, Ho, Yb, Nd) in which the synergistic ligand is 1,10‐phenanthroline (phen) or 2,2′‐bipyridine (bipy). The two series of complexes are [Ln(hfth)3phen] [abbreviated as (Ln)1, where Ln = Er, Ho, Yb] and [Ln(hfth)3bipy] [abbreviated as (Ln)2, where Ln = Er, Ho, Yb, Nd]. Members of the two series have been structurally characterized. The growth morphology, diffuse reflectance (DR) spectra, thermogravimetric analyses, and photophysical studies of these complexes are described in detail. After ligand‐mediated excitation of the complexes, they all show the characteristic near‐infrared (NIR) luminescence of the corresponding Ln3+ ions (Ln = Er, Ho, Yb, Nd). This is attributed to efficient energy transfer from the ligands to the central Ln3+ ions, i.e. an antenna effect. The heptafluorinated substituent in the main hfth sensitizer serves to reduce the degree of vibrational quenching. With these NIR‐luminescent lanthanide complexes, the luminescent spectral region from 1300 to 1600 nm, which is of particular interest for telecommunication applications, can be covered completely. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)