T.-H. HuangW.-T. WhangJ. Y. ShenY.-S. WenJ. T. LinT.-H. KeL.-Y. ChenCHUNG-CHIH WU2018-09-102018-09-102006-01http://scholars.lib.ntu.edu.tw/handle/123456789/325553https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746368848&doi=10.1002%2fadfm.200500823&partnerID=40&md5=53114f142dc9cbcd83978092e2724a4bA series of 2,8-disubstituted dibenzothiophene and 2,8-disubstituted dibenzothiophene-S,S-dioxide derivatives containing quinoxaline and pyrazine moieties are synthesized via three key steps: i) palladium-catalyzed Sonogashira coupling reaction to form dialkynes; ii) conversion of the dialkynes to diones; and iii) condensation of the diones with diamines. Single-crystal characterization of 2,8-di(6,7-dimethyl-3-phenyl-2-quinoxalinyl)-5//-5A6- dibenzo[b,d]thiophene-5,5-dione indicates a triclinic crystal structure with space group P1 and a non-coplanar structure. These new materials are amorphous, with glass-transition temperatures ranging from 132 to 194°C. The compounds (Cpd) exhibit high electron mobilities and serve as effective electron-transport materials for organic light-emitting devices. Double-layer devices are fabricated with the structure indium tin oxide (ITO)/Qn/Cpd/LiF/Al, where yellow-emitting 2,3-bis[4-(N-phenyl-9-ethyl-3-carbazolylamino)phenyl]quinoxaline (Qn) serves as the emitting layer. An external quantum efficiency of 1.41%, a power efficiency of 4.94 lm W-1, and a current efficiency of 1.62 cd A-1 are achieved at a current density of 100 mA cm-2. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.Amorphous materials; Current density; Derivatives; Electron transport properties; Glass transition; Light emitting diodes; Reaction kinetics; Single crystals; Dibenzothiophene; Electron-transport materials; Organic light-emitting devices; Quinoxaline; Nitrogen compoundsjournal article10.1002/adfm.2005008232-s2.0-33746368848WOS:000239543000008