TY - JOUR
T1 - Controlled Excited-State Dynamics and Enhanced Fluorescence Property of Tetrasulfone[9]helicene by a Simple Synthetic Process
AU - Yamamoto, Yuki
AU - Sakai, Hayato
AU - Yuasa, Junpei
AU - Araki, Yasuyuki
AU - Wada, Takehiko
AU - Sakanoue, Tomo
AU - Takenobu, Taishi
AU - Kawai, Tsuyoshi
AU - Hasobe, Taku
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/4/21
Y1 - 2016/4/21
N2 - Tetrasulfone[9]helicene (PTSH) was newly synthesized to improve and evaluate its fluorescence and excited-state dynamics through a single-step oxidation reaction of tetrathia[9]helicene (PTTH). In electrochemical measurements, the reduction potential of PTSH was shifted in a positive direction by approximately 1.0 V when compared to that of PTTH because of its electron-accepting sulfone units. The results of the electrochemical measurements agree with the energy levels calculated by density functional theory (DFT) methods and steady-state spectroscopic measurements. Furthermore, a significant enhancement of the absolute fluorescence quantum yield (ΦFL) was achieved. The absolute fluorescence quantum yield of PTSH attained 0.27, which is approximately 10 times larger than that of PTTH (ΦFL = 0.03). Such an enhancement of ΦFL can be successfully explained by the corresponding kinetic comparison. The reason is mainly the increased energy gap ΔEST between the lowest singlet (S1) and triplet (T1) excited states. Finally, excellent circularly polarized luminescence of PTSH was also observed. The value of the anisotropy factor gCPL was estimated to be 8.3 × 10-4 in PTSH.
AB - Tetrasulfone[9]helicene (PTSH) was newly synthesized to improve and evaluate its fluorescence and excited-state dynamics through a single-step oxidation reaction of tetrathia[9]helicene (PTTH). In electrochemical measurements, the reduction potential of PTSH was shifted in a positive direction by approximately 1.0 V when compared to that of PTTH because of its electron-accepting sulfone units. The results of the electrochemical measurements agree with the energy levels calculated by density functional theory (DFT) methods and steady-state spectroscopic measurements. Furthermore, a significant enhancement of the absolute fluorescence quantum yield (ΦFL) was achieved. The absolute fluorescence quantum yield of PTSH attained 0.27, which is approximately 10 times larger than that of PTTH (ΦFL = 0.03). Such an enhancement of ΦFL can be successfully explained by the corresponding kinetic comparison. The reason is mainly the increased energy gap ΔEST between the lowest singlet (S1) and triplet (T1) excited states. Finally, excellent circularly polarized luminescence of PTSH was also observed. The value of the anisotropy factor gCPL was estimated to be 8.3 × 10-4 in PTSH.
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U2 - 10.1021/acs.jpcc.6b01123
DO - 10.1021/acs.jpcc.6b01123
M3 - Article
AN - SCOPUS:84964545625
SN - 1932-7447
VL - 120
SP - 7421
EP - 7427
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 13
ER -