874101-83-4Relevant academic research and scientific papers
Synthesis, structure, aggregation-induced emission, self-assembly, and electron mobility of 2,5-bis(triphenylsilylethynyl)-3,4-diphenylsiloles
Zhao, Zujin,Liu, Dandan,Mahtab, Faisal,Xin, Linyuan,Shen, Zhongfang,Yu, Yong,Chan, Carrie Y. K.,Lu, Ping,Lam, Jacky W. Y.,Sung, Herman H. Y.,Williams, Ian D.,Yang, Bing,Ma, Yuguang,Tang, Ben Zhong
supporting information; experimental part, p. 5998 - 6008 (2011/07/07)
2,5-Bis(triphenylsilylethynyl)-3,4-diphenylsiloles with different 1,1-substituents [XYSi(CPh)2(C-C≡C-SiPh3) 2] (Ph=phenyl) were synthesized in high yields by the Sonogashira coupling of 2,5-dibromo-3,4-diphenylsiloles with triphenylsilylacetylene, and two of these were characterized crystallographically. Crystal structures and theoretical calculations showed that the new silole molecules had higher conjugation than 2,5-diarylsiloles. They possessed low HOMO and LUMO energy levels due to the electron-withdrawing effect of the triphenylsilylethynyl groups. Cyclic voltammetry analysis revealed low electron affinities, which were comparable to those of perfluoroarylsiloles. B3LYP/6-31* calculations demonstrated that the new siloles possessed large reorganization energies for electron and hole transfers and high electron mobilities. A mobility of up to 1.2 × 10-5 cm2V-1s-1 was obtained by the transient electroluminescence method, which was about fivefold higher than that of tris(8-hydroxyquinolinato)aluminum, a widely used electron-transport material, under the same conditions. All of the silole molecules possessed high thermal stability. Although, their solutions were weakly emissive, their nanoparticle suspensions and thin films emitted intense blue-green light upon photoexcitation, demonstrating a novel feature of aggregation-induced emission (AIE). Polarized emissions were observed in the silole crystals. The addition of solvents, which did not dissolve the silole molecules, into silole-containing solutions caused self-assembly of the molecules, which produced macroscopic fibrils with strong light emissions. Copyright
