d -> f Energy Transfer in a Series of Ir-III/Eu-III Dyads: Energy-Transfer Mechanisms and White-Light Emission (Articolo in rivista)

Type
Label
  • d -> f Energy Transfer in a Series of Ir-III/Eu-III Dyads: Energy-Transfer Mechanisms and White-Light Emission (Articolo in rivista) (literal)
Anno
  • 2011-01-01T00:00:00+01:00 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
  • 10.1021/ic2007759 (literal)
Alternative label
  • D. Sykes; I. S. Tidmarsh; A. Barbieri; I. V. Sazanovich; J. A. Weinstein; M. D. Ward (2011)
    d -> f Energy Transfer in a Series of Ir-III/Eu-III Dyads: Energy-Transfer Mechanisms and White-Light Emission
    in Inorganic chemistry
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • D. Sykes; I. S. Tidmarsh; A. Barbieri; I. V. Sazanovich; J. A. Weinstein; M. D. Ward (literal)
Pagina inizio
  • 11323 (literal)
Pagina fine
  • 11339 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 50 (literal)
Rivista
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo
  • 22 (literal)
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • Univ Sheffield, Dept Chem, Sheffield S3 7HF, S Yorkshire, England Ist ISOF CNR, I-40129 Bologna, Italy (literal)
Titolo
  • d -> f Energy Transfer in a Series of Ir-III/Eu-III Dyads: Energy-Transfer Mechanisms and White-Light Emission (literal)
Abstract
  • An extensive series of blue-luminescent iridium(III) complexes has been prepared containing two phenylpyridine-type ligands and one ligand containing two pyrazolylpyridine units, of which one is bound to frill and the second is pendant. Attachment of {Ln(hfac)(3)} (Ln = Eu, Gd; hfac = anion of 1,1,1,5,5,5,-hexafluoropentanedione) to the second coordination site affords Ir-III/Ln(III) dyads. Crystallographic analysis of several mononuclear iridium(III) complexes and one Ir-III/Eu-III dyad reveals that in most cases the complexes can adopt a folded conformation involving aromatic pi stacking between a phenylpyridine ligand and the bis(pyrazolylpyridine) ligand, but in one series, based on CF3-substituted phenylpyridine ligands coordinated to Ir-III, the steric bulk of the CF3 group prevents this and a quite different and more open conformation arises. Quantum mechanical calculations well reproduce these two types of \"folded\" and \"open\" conformations. In the Ir-III/Eu-III dyads, Ir -> Eu energy transfer occurs with varying degrees of efficiency, resulting in partial quenching of the Ir-III-based blue emission and the appearance of a sensitized red emission from Eu-III. Calculations based on consideration of spectroscopic overlap integrals rule out any significant contribution from Forster (dipole dipole) energy transfer over the distances involved but indicate that Dexter-type (exchange) energy transfer is possible if there is a small electronic coupling that would arise, in part, through pi stacking between components. In some cases, an initial photoinduced electron-transfer step could also contribute to Ir -> Eu energy transfer, as shown by studies on isostructural iridium/gadolinium model complexes. A balance between the blue (Ir-based) and red.(Eu-based) emission components can generate white light. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Prodotto
Autore CNR di
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it