title: Silica sol-gel glasses incorporating dual-luminescent Yb quinolinolato complex: processing, emission and photosensitising properties of the 'antenna' ligand.
abstract: The [Yb(5,7ClQ)(2)(H5,7ClQ)(2)Cl] (1) complex, that exhibits dual-luminescence in the visible (ligand-centered) and in the NIR (Yb-centered), has been incorporated into a silica sol-gel glass obtaining 1-doped glassy material which is optically transparent and homogeneous and with good mechanical properties. The doped sol-gel glass can be considered a "solid state solution" and photophysical studies demonstrate that the emissive properties of the dopant complex are preserved in the silica matrix. Observed NIR decay times fall in the μs range and are likely limited by "second-sphere" matrix interactions. The ligand-to-metal energy transfer mechanism occurs on ultrafast timescale and involves ligand triplet states. The sensitization efficiency of the antenna quinolinolato ligand toward Yb(3+) is estimated to be as high as ~80%. The Yb natural radiative lifetime observed for 1 in MeCN-EtOH solution (τ(rad) = 438 μs) is the shortest reported so far for ytterbium complexes.
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Monserrato-Cagliari, Italy. f.artizzu@unica.it
authors.forename: Flavia
authors.initials: F
authors.lastname: Artizzu
authors.forename: Francesco
authors.initials: F
authors.lastname: Quochi
authors.forename: Michele
authors.initials: M
authors.lastname: Saba
authors.forename: Danilo
authors.initials: D
authors.lastname: Loche
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Mercuri
authors.forename: Angela
authors.initials: A
authors.lastname: Serpe
authors.forename: Andrea
authors.initials: A
authors.lastname: Mura
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bongiovanni
authors.forename: Paola
authors.initials: P
authors.lastname: Deplano
mesh_terms: D002739:Chloroquinolinols / Q000737:chemistry; D005898:Glass; D008024:Ligands; D049449:Luminescence; D017319:Photosensitizing Agents / Q000737:chemistry*; D058428:Silica Gel / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D002739:Chloroquinolinols; D008024:Ligands; D017319:Photosensitizing Agents; D058428:Silica Gel; D015018:Ytterbium