Synthesis, Characterization and Properties of Novel Star-Shaped π-Conjugated Oligomers with Triphenylamine Core

Authors

  • Leijing Liu,

    1. State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, Jilin 130012, China
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  • Qing Guo,

    1. State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, Jilin 130012, China
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  • Jiyang Li,

    1. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, Jilin 130012, China
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  • Bin Yao,

    1. Key Laboratory of Physics and Technology for Advanced Batteries, Ministry of Education, Jilin University, Changchun, Jilin 130012, China
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  • Wenjing Tian

    Corresponding author
    1. State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, Jilin 130012, China
    • State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, Jilin 130012, China, Tel.: 0086-0431-85166368; Fax: 0086-0431-85193421
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Abstract

Four new star-shaped π-conjugated oligomers (TPA-CZ3, TPA-TPA3, TPA-PTZ3 and TPA-BT3) with triphenylamine as a core and different electron-donating ability groups, carbazole, triphenylamine, phenothiazine and bithiophene, as peripheral units have been designed and synthesized via the Heck reaction. These oligomers show good solubility in common organic solvents. Their photophysical, electrochemical, electronic structure and charge transfer properties between these star-shaped π-conjugated oligomers and N,N′-bis(1-ethylpropyl)-3,4:9,10-perylene bis(tetracarboxyl diimide) (EP-PDI) have been investigated by UV-vis absorption spectra, photoluminescence (PL) spectra, cyclic voltammetry (CV) measurement, theoretical calculations and fluorescence quenching. The results show that the absorptions and fluorescences of TPA-CZ3, TPA-TPA3 and TPA-PTZ3 are red shifted with the electron-donating ability of the peripheral unit increasing from carbazole to triphenylamine and phenothiazine. In addition, although the bithiophene group has a weaker electron-donating ability than carbazole, triphenylamine and phenothiazine, the absorption and fluorescence of TPA-BT3 have a red shift than those of TPA-CZ3, TPA-TPA3 and TPA-PTZ3 because TPA-BT3 has a longer conjugation length than TPA-CZ3, TPA-TPA3 and TPA-PTZ3. The triphenylamine core and the peripheral units can constitute a large conjugated structure. The fluorescence quenching properties indicate that efficient charge transfer can happen between the star-shaped oligomers and EP-PDI.

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