Lanthanide pentafluorophenolates. Synthesis, structure and luminescent properties

The pentafluorophenolates of lanthanides Ln(OC6F5)3 (Ln = Nd (1), Tb (2), Er (3)) were prepared by the reactions of pentafluorophenol with appropriate silylamides Ln[N(SiMe3)2]3 in benzene or toluene solution. The same reactions in ether or methanol medium afforded the solvated complexes Ln(OC6F5)3(Et2O)3 (Ln = Nd (4), Eu (5), Tb (6), Er (7), Gd (8)) or Nd(OC6F5)3(MeOH)3 (9), respectively. The phenanthroline complexes Ln(C6F5O)3(phen) (Ln = Pr (10), Nd (11), Er (12)), Ln(OC6F5)3(phen)2 (Ln = Sm (13), Tb (14), Ho (15), Ln(OC6F5)3(phen)2(Et2O) (Ln = Eu (16), Yb (17)), and Ln(OC6F5)3(phen)(Et2O)3 (Ln = Eu (18), Nd (19), Ce (20), Dy (21)), Ln(OC6F5)3(phen)2(H2O) (Ln = Sm (22), Ho (23)), and Gd(OC6F5)3(phen)2(MeOH) (24) were obtained when the reactions were carried out in the presence of 1,10-phenanthroline. The complexes with pyridine Tb(OC6F5)3(py)5 (25) and 2,2′-bipyridyl Ln(OC6F5)3(bpy)2 (Ln = Tb (26), Yb (27)) were synthesized similarly. Compounds 7, 22, 23, and 24 were characterized by X-ray analysis. The complexes Ln(OC6F5)3 decompose above 150 °C in vacuum to give lanthanide fluorides and octofluorodibenzo-p-dioxine. Phenanthroline derivatives are stable up to 310 °C. Luminescence spectra of all the obtained complexes in visible region contain a broad band of ligand-centered emission peaked at 405–415 nm. Spectra of samarium 13, europium 5, 16, 18 and terbium 14, 25, 26 derivatives display also the characteristic narrow bands of Sm3+, Eu3+ and Tb3+ ions.