Jump to main content
Jump to site search

Issue 55, 2017
Previous Article Next Article

Rational design of doubly-bridged chromophores for singlet fission and triplet–triplet annihilation

Author affiliations

Abstract

We demonstrate rational designs of excitation energies and electronic couplings using doubly-bridged chromophores for exciton down- and up-conversions, the former and latter of which are known as singlet fission and triplet–triplet annihilation, respectively. We deduce energetic conditions suitable for these two conversion processes based on quantum interferences within a bridge as well as between two bridges. The idea is at first proposed at the Hückel approximation level of theory in a theoretical model, and then, is realized for molecular systems of polyyne bridges with several lengths of ethynyl units as well as with different linked sites by ab initio quantum chemistry calculation. The result is analyzed in detail by decomposing the electronic couplings into direct-overlap and bridge-mediated couplings from each bridge, which definitely confirms the quantum interference between the bridges. Further analysis using perturbation theory clarifies this effect on the energetics concerning singlet fission and triplet–triplet annihilation. Estimation of the singlet fission time constants for the molecules designed to have exothermic singlet fission gave 102–104 ps, which is much faster than for most tetracene dimers reported previously. The present study provides a widely applicable molecular design guideline for tuning the energetic conditions by selective control of the electronic coupling matrix elements, which can be systematically achieved by considering the relative phases and distributions of the π-orbitals in chromophores and bridges.

Graphical abstract: Rational design of doubly-bridged chromophores for singlet fission and triplet–triplet annihilation

Back to tab navigation

Supplementary files

Publication details

The article was received on 30 May 2017, accepted on 04 Jul 2017 and first published on 11 Jul 2017


Article type: Paper
DOI: 10.1039/C7RA06032G
Citation: RSC Adv., 2017,7, 34830-34845
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Rational design of doubly-bridged chromophores for singlet fission and triplet–triplet annihilation

    S. Ito, T. Nagami and M. Nakano, RSC Adv., 2017, 7, 34830
    DOI: 10.1039/C7RA06032G

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements