Platinum(II) complexes with cyclometallated 5-pi-delocalized-donor-1,3-di(2-pyridyl)benzene ligands as efficient phosphors for NIR-OLEDs

Nisic, F.; Colombo, A.; Dragonetti, C.; Roberto, D.; Valore, A.; Malicka, J.M.; Cocchi, M.; Freeman, G.R.; Williams, J.A.G.

Abstract

Two new pincer proligands, namely 5-(p-(N,N-diphenylamino)phenylethynyl)-1,3-di(2-pyridyl)benzene (HL1) and trans-5-(p-(N,N-diphenylamino)styryl-1,3-di(2-pyridyl)benzene (HL2) were prepared together with their N^C^N-coordinated cyclometallated platinum(II) complexes PtL1X (X = Cl, NCS) and PtL2Cl. Both ligands are intensely luminescent in solution (quantum yields > 0.8). PtL1X complexes display high quantum yields in solution whereas that of PtL2Cl is very low due to the ease with which trans to cis isomerisation of the diphenylaminostyryl C[double bond, length as m-dash]C bond occurs. Distinct sets of emission bands attributable to the cis and trans forms are observable in glass at 77 K, the assignments being supported by TD-DFT calculations. Organic light-emitting diodes (OLEDs) have been prepared using the new compounds as phosphorescent emitters. Remarkably, despite the inferior quantum yield of PtL2Cl in solution, the best electroluminescence quantum efficiencies are obtained with this complex, which emerges as an excellent candidate for the preparation of NIR-OLEDs.

Citation

Nisic, F., Colombo, A., Dragonetti, C., Roberto, D., Valore, A., Malicka, J., …Williams, J. (2014). Platinum(II) complexes with cyclometallated 5-pi-delocalized-donor-1,3-di(2-pyridyl)benzene ligands as efficient phosphors for NIR-OLEDs. Journal of Materials Chemistry C Materials for optical and electronic devices, 2(10), 1791-1800. https://doi.org/10.1039/c3tc32086c

• Journal Article Type: Article
• Publication Date: Mar 14, 2014
• Deposit Date: Jan 17, 2014
• Publicly Available Date: Jul 28, 2014
• Journal: Journal of Materials Chemistry C Materials for optical and electronic devices
• Print ISSN: 2050-7526
• Electronic ISSN: 2050-7534
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 2
• Issue: 10
• Pages: 1791-1800
• DOI: https://doi.org/10.1039/c3tc32086c
• Public URL: https://durham-repository.worktribe.com/output/1445292