Journal article

Triplet state formation in photoexcited slip-stacked perylene-3,4:9,10- bis(dicarboximide) dimers on a xanthene scaffold

Lefler K, Brown K, Salamant W, Dyar S, Knowles K, Wasielewski M ...see all

Journal of Physical Chemistry A, vol. 117, issue 40 (2013) pp. 10333-10345

  • 39


    Mendeley users who have this article in their library.
  • 28


    Citations of this article.
Sign in to save reference


Two covalent perylene-3,4:9,10-bis(dicarboximide) (PDI) dimers in which the PDI molecules are attached to a xanthene (Xan) scaffold in which the long axes of the two π-π stacked PDI molecules are slipped by 4.3 and 7.9 Å were prepared. These dimers are designed to mimic J-aggregates and provide insights into the photophysics of triplet state formation in PDI aggregates that target organic electronics. Using ultrafast transient absorption and stimulated Raman spectroscopy, the mechanism of (3)*PDI formation was found to depend strongly on a competition between the rate of Xan(•+)-PDI(•-) formation involving the spacer group and the rate of excimer-like state formation. Which mechanism is favored depends on the degree of electronic coupling between the two PDI molecules and/or solvent polarity. Singlet exciton fission to produce (3)*PDI does not compete kinetically with these processes. The excimer-like state decays relatively slowly with τ = 28 ns to produce (3)*PDI, while charge recombination of Xan(•+)-PDI(•-) yields (3)*PDI more than an order of magnitude faster. The perpendicular orientation between the π orbitals of PDI and the Xan bridge provides a large enough orbital angular momentum change to greatly increase the intersystem crossing rate via Xan(•+)-PDI(•-) → (3)*PDI charge recombination. These results highlight the importance of understanding inter-chromophore electronic coupling in a wide range of geometries as well as the active role that molecular spacers can play in the photophysics of covalent models for self-assembled chromophore aggregates.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • Kelly M. Lefler

  • Kristen E. Brown

  • Walter A. Salamant

  • Scott M. Dyar

  • Kathryn E. Knowles

  • Michael R. Wasielewski

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free