Lanthanide pentafluorophenolates. Synthesis, structure and luminescent properties

摘要

The pentafluorophenolates of lanthanides Ln(OC_6F _5)_3 (Ln = Nd (1), Tb (2), Er (3)) were prepared by the reactions of pentafluorophenol with appropriate silylamides Ln[N(SiMe _3)_2]_3 in benzene or toluene solution. The same reactions in ether or methanol medium afforded the solvated complexes Ln(OC _6F_5)_3(Et_2O)_3 (Ln = Nd (4), Eu (5), Tb (6), Er (7), Gd (8)) or Nd(OC_6F_5) _3(MeOH)_3 (9), respectively. The phenanthroline complexes Ln(C_6F_5O)_3(phen) (Ln = Pr (10), Nd (11), Er (12)), Ln(OC_6F_5)_3(phen)_2 (Ln = Sm (13), Tb (14), Ho (15), Ln(OC_6F_5)_3(phen) 2(Et_2O) (Ln = Eu (16), Yb (17)), and Ln(OC _6F_5)_3(phen)(Et_2O)_3 (Ln = Eu (18), Nd (19), Ce (20), Dy (21)), Ln(OC_6F_5) _3(phen)_2(H_2O) (Ln = Sm (22), Ho (23)), and Gd(OC_6F_5)_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(OC_6F _5)_3(py)_5 (25) and 2,2'-bipyridyl Ln(OC_6F_5)_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(OC_6F_5)_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 Sm~(3+), Eu~(3+) and Tb 3+ ions.