Jean-Claude Bunzli - Influence of Symmetry on the Luminescence and Radiative Lifetime of Nine-Coordinate Europium Complexes

Version 1

      Publication Details (including relevant citation   information):

      Shavaleev,Nail M., Eliseeva,Svetlana V., Scopelliti,Rosario,   B nzli,Jean-Claude G. Inorganic Chemistry  2015 54 (18) 9166-9173

      Abstract: Homoleptic mononuclear nine-coordinate   lanthanum(III) and europium(III) tris-complexes [Ln(N^N^O)3] nH2O   with two tridentate N-benzyl-benzimidazole   pyridine-2-carboxylates exhibit a rare C3-symmetry of the   lanthanide coordination polyhedron in the solid state, as   confirmed by luminescence spectroscopy and by X-ray   crystallography (the three N^N^O ligands are arranged "up-up-up"   around the lanthanide ion). The symmetry, however, is changed to   the more-common C1 upon dissolution of the complexes in   dichloromethane, as revealed by luminescence spectroscopy (the   three ligands are arranged "up-up-down"). The new europium   complexes emit efficient ligand-sensitized metal-centered   luminescence with excited-state lifetimes of 1.56-2.18 ms and   quantum yields of 25-41% in the solid and in the solution. The   change of the symmetry from (a higher) C3 to (a lower) C1 alters   the luminescence spectrum, shortens the radiative lifetime, and   increases the luminescence efficiency of the europium complexes.

      Address (URL):