TY - JOUR
T1 - Intramolecular interactions of highly π-conjugated perylenediimide oligomers probed by single-molecule spectroscopy
AU - Cho, Jae Won
AU - Yoo, Hyejin
AU - Lee, Ji Eun
AU - Yan, Qifan
AU - Zhao, Dahui
AU - Kim, Dongho
N1 - Publisher Copyright:
© 2014 American Chemical Society.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/11/6
Y1 - 2014/11/6
N2 - Highly π-conjugated perylenediimide (PDI) oligomers are promising low band gap organic materials for various applications in optoelectronics. In this work, individual fluorescence dynamics of ethynylene- and butadiynylene-bridged dimeric and trimeric PDIs (PEP, PBP, and PEPEP) were monitored and analyzed by single-molecule fluorescence spectroscopy to gain information on the degree of extension of π-conjugation through the acetylene bridge in PDI multichromophores. The simultaneous measurements of fluorescence intensity, lifetime, and spectrum indicate a sequential decrease in π-conjugation upon photobleaching of PDI monomer units. Furthermore, Huang-Rhys (HR) factors, S, are obtained to evaluate the degree of electronic coupling in view of π-conjugation and overall rigidity between the PDI units in PDI oligomers at the single-molecule level. In addition, butadiynylene-bridged dimeric PDI (PBP) reveals conformational heterogeneity due to the long butadiynylene linker. These results suggest a new way to control the photophysical properties of the PDI multichromophoric system by expansion of π-conjugation and modification with different linker groups. (Graph Presented).
AB - Highly π-conjugated perylenediimide (PDI) oligomers are promising low band gap organic materials for various applications in optoelectronics. In this work, individual fluorescence dynamics of ethynylene- and butadiynylene-bridged dimeric and trimeric PDIs (PEP, PBP, and PEPEP) were monitored and analyzed by single-molecule fluorescence spectroscopy to gain information on the degree of extension of π-conjugation through the acetylene bridge in PDI multichromophores. The simultaneous measurements of fluorescence intensity, lifetime, and spectrum indicate a sequential decrease in π-conjugation upon photobleaching of PDI monomer units. Furthermore, Huang-Rhys (HR) factors, S, are obtained to evaluate the degree of electronic coupling in view of π-conjugation and overall rigidity between the PDI units in PDI oligomers at the single-molecule level. In addition, butadiynylene-bridged dimeric PDI (PBP) reveals conformational heterogeneity due to the long butadiynylene linker. These results suggest a new way to control the photophysical properties of the PDI multichromophoric system by expansion of π-conjugation and modification with different linker groups. (Graph Presented).
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U2 - 10.1021/jz501765x
DO - 10.1021/jz501765x
M3 - Article
AN - SCOPUS:84908618457
VL - 5
SP - 3895
EP - 3901
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 21
ER -