Here,9,9.9'-tris(4-butoxyphenyl)-9H-9'Hl-2,2'-difluorene(DF)was synthesized as a reference for compa rison,and diphenyl sulfone and triphenylphosphine oxygen were introduced to the 9-position of fluorene t...Here,9,9.9'-tris(4-butoxyphenyl)-9H-9'Hl-2,2'-difluorene(DF)was synthesized as a reference for compa rison,and diphenyl sulfone and triphenylphosphine oxygen were introduced to the 9-position of fluorene througha C-H coupling reaction to produce two fluorene-based oligomers 9′,9′″-sulfonylbis(4.1-phenylene)bis9,9′,9′tris(4-butoxyphenyl)-9H,9'H-2.2'-bifluorene(DF)SOz and phenylbis(4-{9.9,9-tris(4-butoxyphenyl)-9H,9'H-12.2-bif-luorenel-9-yl} phenyl)phosphine oxidel(DF)2POI.Solid powders of all the three compounds exhibit excellent therma stability with thermal temperature at 5%mass loss of 375,429 and 383 C for(DF)2SO2,(DF)PO and DF.In addition,owing to the distorted molecular structure and weak electron-absorbing ability of the acceptor,(DF)Soz and(DF)2PO do not have obvious intramolecular charge transfer characteristics.and exhibit stable localized 394 nm/375 nm fluorescence emission peaks in different polar solvents.The absolute luminescence quantumefficiencies of(DF)2S02,(DF)PO and DF solid powders are 20.83%,10.03%and 59.46%,Compound DF has the highest quantum yield as an electron donor.The chromaticity coordinates of the blue OLED devices based on DF and DF2SO2 fabricated by solution spin coating were(0.19.0.10)and(0.19.0.11).which were closest to the deep blue region,and the corresponding maximum external quantum efficiencies are 1.45%and 0.87%,respectively,which are higher than that of(DF)2PO(0.25%)and consistent with the difference in the solid-state quantum efficiency between them.展开更多
基金Supported by the National Natural Science Foundation of China(No.21574068)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(No.YX030003).
文摘Here,9,9.9'-tris(4-butoxyphenyl)-9H-9'Hl-2,2'-difluorene(DF)was synthesized as a reference for compa rison,and diphenyl sulfone and triphenylphosphine oxygen were introduced to the 9-position of fluorene througha C-H coupling reaction to produce two fluorene-based oligomers 9′,9′″-sulfonylbis(4.1-phenylene)bis9,9′,9′tris(4-butoxyphenyl)-9H,9'H-2.2'-bifluorene(DF)SOz and phenylbis(4-{9.9,9-tris(4-butoxyphenyl)-9H,9'H-12.2-bif-luorenel-9-yl} phenyl)phosphine oxidel(DF)2POI.Solid powders of all the three compounds exhibit excellent therma stability with thermal temperature at 5%mass loss of 375,429 and 383 C for(DF)2SO2,(DF)PO and DF.In addition,owing to the distorted molecular structure and weak electron-absorbing ability of the acceptor,(DF)Soz and(DF)2PO do not have obvious intramolecular charge transfer characteristics.and exhibit stable localized 394 nm/375 nm fluorescence emission peaks in different polar solvents.The absolute luminescence quantumefficiencies of(DF)2S02,(DF)PO and DF solid powders are 20.83%,10.03%and 59.46%,Compound DF has the highest quantum yield as an electron donor.The chromaticity coordinates of the blue OLED devices based on DF and DF2SO2 fabricated by solution spin coating were(0.19.0.10)and(0.19.0.11).which were closest to the deep blue region,and the corresponding maximum external quantum efficiencies are 1.45%and 0.87%,respectively,which are higher than that of(DF)2PO(0.25%)and consistent with the difference in the solid-state quantum efficiency between them.