Enthalpy-Entropy Compensation Effect for Triplet Pair Dissociation of Intramolecular Singlet Fission in Phenylene Spacer-Bridged Hexacene Dimers

Shunta Nakamura, Hayato Sakai, Masaaki Fuki, Yasuhiro Kobori, Nikolai V. Tkachenko, Taku Hasobe

Research output: Contribution to journalArticlepeer-review

Abstract

Hexacene (Hc) is highly promising for singlet fission (SF). However, the number of SFs in Hc is extremely limited. As far as Hc dimers in solution are concerned, there is no report on the observation of the dissociation process from a correlated triplet pair (TT) to an individual one. The emphasis in this study is on the first observation of the quantitative TT generation together with the orientation-dependent photophysical discussions for TT dissociation usingpara- andmeta-phenyl-bridged Hc dimers. Moreover, the activation enthalpies of Hc dimers in TT dissociation are smaller than those of pentacene (Pc) dimers, whereas the relative entropic contributions for Gibbs free energy of activation are much larger than the enthalpic ones in both Hc and Pc dimers. This implies that the vibrational motions are responsible for the intramolecular conformation changes associated with the TT dissociation. Consequently, “enthalpy-entropy compensation” has a large impact on the rate constants and quantum yields.

Original languageEnglish
Pages (from-to)6457-6463
Number of pages7
JournalJournal of Physical Chemistry Letters
Volume12
Issue number28
DOIs
Publication statusPublished - 2021 Jul 22

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Enthalpy-Entropy Compensation Effect for Triplet Pair Dissociation of Intramolecular Singlet Fission in Phenylene Spacer-Bridged Hexacene Dimers'. Together they form a unique fingerprint.

Cite this