Intramolecular interactions of highly π-conjugated perylenediimide oligomers probed by single-molecule spectroscopy

Jae Won Cho, Hyejin Yoo, Ji Eun Lee, Qifan Yan, Dahui Zhao, Dongho Kim

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

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).

Original languageEnglish
Pages (from-to)3895-3901
Number of pages7
JournalJournal of Physical Chemistry Letters
Volume5
Issue number21
DOIs
Publication statusPublished - 2014 Nov 6

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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