Remarkable high efficiency of red emitters using Eu(iii) ternary complexes

Abstract

We have synthesized Eu(iii) ternary complexes possessing record photoluminescence yields up to 90%. This high luminescence performance resulted from the absence of quenching moieties in the Eu coordination environment and an efficient energy transfer between ligands, combined with a particular symmetry of the coordination environment.

Review on the Electroluminescence Study of Lanthanide Complexes

“…Utochnikova and Kalyakina et al introduced carboxylic acid analogues into europium(III) complexes Eu‐98 to Eu‐106 ( Scheme ). Among which the PLQY of Eu‐100 reached 90%.…”

On the Structural Features of Substituted Lanthanide Benzoates

“…the study of a mononuclear nine‐coordinate europium tris complexes with two tridentate N‐benzylbenzimidazole pyridine‐2‐carboxylates and its solution in dichloromethane revealed that the change of the symmetry upon dissolution from a higher C 3 to a lower C 1 shortened the radiative lifetime, resulting in the increase of the luminescence efficiency of the europium complexes. In ref . a significant increase of the quantum yield upon addition of an neutral auxiliary ligand was observed due to the change of the coordination polyhedron from higher symmetrical distorted snub disphenoid to a lower‐symmetry distorted tricapped trigonal prism.…”

Phenanthroline—A Versatile Ligand for Advanced Functional Polymeric Materials

“…Non-modified 1,10-phenanthrolinei sapoor emissive compound, yet, for example, ac oordination to lanthanides, turns the molecule into at riplet state photosensitizer.I nvestigationso fE u III as well as Tb III phen complexes showedt hat the ligand may act as an antenna, enhancing the fluorescenceo f the poorly absorbing lanthanide ions. [8,9,63,64] An advantage of lanthanide complexes are their sharp emission spectra, originating from shielded inner-shell 4f orbitals. [65] As their fluorescence arises from forbidden intramolecular f-f transitions,i th as al ong-lived excited-state lifetime.…”

“…Furthermore, upon coordination to metal‐ions, some phen complexes exhibit unique photophysical properties . As a triplet state photosensitizer, phen is exploited as a light harvesting antenna for enhancing the fluorescence of poorly absorbing metal‐ions, such as Eu III or Tb III …”

“…[2,6] As at riplet state photosensitizer, [7] phen is exploited as al ight harvesting antennaf or enhancing the fluorescenceo fp oorly absorbing metal-ions, such as Eu III or Tb III . [8,9] Given its versatile chemicaln ature, phen-based linkersh ave been exploited as building blocks in variousm acromolecular systems as well as fors urfacef unctionalization, enabling the incorporationo ft ask-specificm etal-ions. [6,10,11] Of particular interesti st he embedding of metal-ionsi nto polymeric architectures.H ere, the properties of polymer chains can readily be tuned,i ncluding their solubility behavior,t emperature stability and functionalization, thusa llowing their precise adjustment to selected tasks.…”