Thermally robust and tuneable phosphorescent gold(III) complexes bearing (N^N)-type bidentate ligands as ancillary chelates

Robert Malmberg, Michael Bachmann, Olivier Blacque, Koushik Venkatesan

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Phosphorescent mono-cyclometalated gold(III) complexes and their possible applications in organic light emitting diodes (OLEDs) can be significantly enhanced with their improved thermal stability by suppressing the reductive elimination of the respective ancillary ligands. A rational tuning of the π-conjugation of the cyclometalating ligand in conjunction with the non-conjugated 5,5′-(1-methylethylidene)bis(3-trifluoromethyl)-1H-pyrazole were used as a strategy to achieve room-temperature phosphorescence emission in a new series of gold(III) complexes. Photophysical studies of the newly synthesised and characterised complexes revealed phosphorescent emission of the complexes at room temperature in solution, thin films when doped in poly(methyl methacrylate) (PMMA) as well as in 2-Me-THF at 77 K. The complexes exhibit highly tuneable emission behaviour with photoluminescent quantum efficiencies up to 22 % and excited state lifetimes in the range of 63–300 μs. Detailed photophysical investigations in combination with DFT and TD-DFT calculations support the conclusion that the emission properties are strongly dictated by both the cyclometalating ligand and the ancillary chelating ligand. Thermogravimetric studies further show that the thermal stability of the Au III complexes has been drastically enhanced, making these complexes more attractive for OLED applications.

LanguageEnglish
Pages3627-3636
Number of pages10
JournalChemistry - A European Journal
Volume25
Issue number14
DOIs
Publication statusPublished - 7 Mar 2019

Fingerprint

Bearings (structural)
Gold
Ligands
Organic light emitting diodes (OLED)
Discrete Fourier transforms
Thermodynamic stability
Phosphorescence
Polymethyl Methacrylate
Chelation
Quantum efficiency
Polymethyl methacrylates
Excited states
Tuning
Thin films
Temperature

Keywords

  • gold
  • metallacycles
  • nitrogen heterocycles
  • N,N ligands
  • OLED
  • phosphorescence

Cite this

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title = "Thermally robust and tuneable phosphorescent gold(III) complexes bearing (N^N)-type bidentate ligands as ancillary chelates",
abstract = "Phosphorescent mono-cyclometalated gold(III) complexes and their possible applications in organic light emitting diodes (OLEDs) can be significantly enhanced with their improved thermal stability by suppressing the reductive elimination of the respective ancillary ligands. A rational tuning of the π-conjugation of the cyclometalating ligand in conjunction with the non-conjugated 5,5′-(1-methylethylidene)bis(3-trifluoromethyl)-1H-pyrazole were used as a strategy to achieve room-temperature phosphorescence emission in a new series of gold(III) complexes. Photophysical studies of the newly synthesised and characterised complexes revealed phosphorescent emission of the complexes at room temperature in solution, thin films when doped in poly(methyl methacrylate) (PMMA) as well as in 2-Me-THF at 77 K. The complexes exhibit highly tuneable emission behaviour with photoluminescent quantum efficiencies up to 22 {\%} and excited state lifetimes in the range of 63–300 μs. Detailed photophysical investigations in combination with DFT and TD-DFT calculations support the conclusion that the emission properties are strongly dictated by both the cyclometalating ligand and the ancillary chelating ligand. Thermogravimetric studies further show that the thermal stability of the Au III complexes has been drastically enhanced, making these complexes more attractive for OLED applications.",
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Thermally robust and tuneable phosphorescent gold(III) complexes bearing (N^N)-type bidentate ligands as ancillary chelates. / Malmberg, Robert; Bachmann, Michael; Blacque, Olivier; Venkatesan, Koushik.

In: Chemistry - A European Journal, Vol. 25, No. 14, 07.03.2019, p. 3627-3636.

Research output: Contribution to journalArticleResearchpeer-review

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T1 - Thermally robust and tuneable phosphorescent gold(III) complexes bearing (N^N)-type bidentate ligands as ancillary chelates

AU - Malmberg, Robert

AU - Bachmann, Michael

AU - Blacque, Olivier

AU - Venkatesan, Koushik

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