Jump to main content
Jump to site search

Issue 33, 2017
Previous Article Next Article

Pyridylpyrazole N^N ligands combined with sulfonyl-functionalised cyclometalating ligands for blue-emitting iridium(III) complexes and solution-processable PhOLEDs

Author affiliations

Abstract

A series of blue iridium(III) complexes (12–15) comprising sulfonyl-functionalised phenylpyridyl cyclometalating ligands and pyridylpyrazole N^N ligands are reported, with an X-ray crystal structure obtained for 12. The complexes are highly emissive with photoluminescence quantum yields of 0.52–0.70 in dichloromethane solutions: two of the complexes (12 and 14) show emissions at λPLmax 457 nm which is considerably blue-shifted compared to the archetypal blue emitter FIrpic (λmax 468 nm). The short excited state lifetimes (1.8–3.3 μs) and spectral profiles are consistent with phosphorescence from a mixture of ligand-centred and MLCT excited states. Density functional (DFT) and time dependent DFT (TD-DFT) calculations are in agreement with the electrochemical properties and the blue phosphorescence of the complexes. The additional mesityl substituent on the pyridylpyrazole ligand of 12 and 13 enhances the solubility of the complexes facilitating thin film formation by solution processing. Phosphorescent organic light-emitting diodes (PhOLEDs) have been fabricated using 12 or 13 in a solution-processed single-emitting layer using either poly(vinylcarbazole) (PVK) or 1,3-bis(N-carbazolyl)benzene (mCP) as host. The most blue-shifted electroluminescence (λELmax 460 nm, CIEx,y 0.15, 0.21) is obtained for an OLED containing complex 12 and mCP, with a brightness of 5400 cd m−2 at 10 V which is high for PhOLEDs with similar blue CIE coordinates using a solution-processed emitter layer.

Graphical abstract: Pyridylpyrazole N^N ligands combined with sulfonyl-functionalised cyclometalating ligands for blue-emitting iridium(iii) complexes and solution-processable PhOLEDs

Back to tab navigation

Supplementary files

Publication details

The article was received on 23 Jun 2017, accepted on 27 Jul 2017 and first published on 04 Aug 2017


Article type: Paper
DOI: 10.1039/C7DT02289A
Citation: Dalton Trans., 2017,46, 10996-11007
  • Open access: Creative Commons BY license
  •   Request permissions

    Pyridylpyrazole N^N ligands combined with sulfonyl-functionalised cyclometalating ligands for blue-emitting iridium(III) complexes and solution-processable PhOLEDs

    H. Benjamin, M. A. Fox, A. S. Batsanov, H. A. Al-Attar, C. Li, Z. Ren, A. P. Monkman and M. R. Bryce, Dalton Trans., 2017, 46, 10996
    DOI: 10.1039/C7DT02289A

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements