title: 2,2'-Bipyrimidine as efficient sensitizer of the solid-state luminescence of lanthanide and uranyl ions from visible to near-infrared.
abstract: Treatment of Ln(NO(3))(3)nH(2)O with 1 or 2 equiv 2,2'-bipyrimidine (BPM) in dry THF readily afforded the monometallic complexes [Ln(NO(3))(3)(bpm)(2)] (Ln=Eu, Gd, Dy, Tm) or [Ln(NO(3))(3)(bpm)(2)]THF (Ln=Eu, Tb, Er, Yb) after recrystallization from MeOH or THF, respectively. Reactions with nitrate salts of the larger lanthanide ions (Ln=Ce, Nd, Sm) yielded one of two distinct monometallic complexes, depending on the recrystallization solvent: [Ln(NO(3))(3)(bpm)(2)]THF (Ln=Nd, Sm) from THF, or [Ln(NO(3))(3)(bpm)(MeOH)(2)]MeOH (Ln=Ce, Nd, Sm) from MeOH. Treatment of UO(2)(NO(3))(2)6H(2)O with 1 equiv BPM in THF afforded the monoadduct [UO(2)(NO(3))(2)(bpm)] after recrystallization from MeOH. The complexes were characterized by their crystal structure. Solid-state luminescence measurements on these monometallic complexes showed that BPM is an efficient sensitizer of the luminescence of both the lanthanide and the uranyl ions emitting visible light, as well as of the Yb(III) ion emitting in the near-IR. For Tb, Dy, Eu, and Yb complexes, energy transfer was quite efficient, resulting in quantum yields of 80.0, 5.1, 70.0, and 0.8 %, respectively. All these complexes in the solid state were stable in air.
authors.affiliation: CEA, IRAMIS, SIS2 M, Laboratoire Claude Fréjacques, CNRS URA 331, 91191 Gif-sur-Yvette, France. gael.zucchi@cea.fr
authors.forename: Gaël
authors.initials: G
authors.lastname: Zucchi
authors.forename: Olivier
authors.initials: O
authors.lastname: Maury
authors.forename: Pierre
authors.initials: P
authors.lastname: Thuéry
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gumy
authors.forename: Jean-Claude G
authors.initials: JC
authors.lastname: Bünzli
authors.forename: Michel
authors.initials: M
authors.lastname: Ephritikhine
mesh_terms: D018360:Crystallography, X-Ray; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D049449:Luminescence; D008968:Molecular Conformation; D011743:Pyrimidines / Q000138:chemical synthesis / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D014466:Ultraviolet Rays; D014501:Uranium / Q000737:chemistry*
chemical_list: D028581:Lanthanoid Series Elements; D011743:Pyrimidines; D014501:Uranium