Synthesis and properties of a thiophene-substituted diaza[7]helicene for application as a blue emitter in organic light-emitting diodes. Issue 6 (8th February 2017)

• Record Type: Journal Article
• Authors: Chen, Ting; Zhang, Baojie; Liu, Zhi; Duan, Lian; Dong, Guifang; Feng, Ying; Luo, Xinyu; Cui, Deliang
• Is Part Of: Tetrahedron letters. Volume 58:Issue 6(2017)
• Page Start: 531
• Page End: 535
• Publication Date: 2017-02-08
• Subjects: Thiophene-substituted diaza[7]helicene -- Fluorescence -- Blue-emitting material -- OLED; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2016.12.069
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: A synthetic route to a thiophene-substituted diaza[7]helicene was demonstrated. Fluorescence quantum yield up to 32% of this compound in acetidin was reported. Great improvement of EQE of 0.41% of a doped OLED based on this compound was made. Abstract: Carbazole-based diaza[7]helicene substituted by thiophene groups, 2, 12-dithiophene-5, 15-dihexyl-5, 15-diaza[7]helicene (6 ), was synthesised successfully and confirmed by 1 H NMR, 13 C NMR, High Resolution Mass Spectrometry, Time of Flight Mass Spectrometry. Compound6 exhibited good solubility and excellent thermal stability with no melting point and a high decomposition temperature of 453.64 °C. A doped device with a structure of ITO/NPB (50 nm)/CBP: 10%6 (30 nm)/Bphen (20 nm)/Mg:Ag (150 nm)/Ag (50 nm) emitted the blue light at 460 nm with Commission Internationale de LEclairage (CIE) coordinate of (0.176, 0.26). The maximum brightness and external quantum efficiency (EQE) were 2306 cd m −2 and 0.41%, respectively.