Two-Dimensional Electronic Spectroscopy Reveals Excitation Energy-Dependent State Mixing during Singlet Fission in a Terrylenediimide Dimer

Aritra Mandal, Michelle Chen, Eileen D. Foszcz, Jonathan D. Schultz, Nicholas M. Kearns, Ryan M. Young, Martin T. Zanni, Michael R. Wasielewski

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Singlet fission (SF) is a spin-allowed process in which a singlet exciton, 1 (S 1 S 0 ), within an assembly of two or more chromophores spontaneously down-converts into two triplet excitons via a multiexciton correlated triplet pair state, 1 (T 1 T 1 ). To elucidate the involvement of charge transfer (CT) states and vibronic coupling in SF, we performed 2D electronic spectroscopy (2DES) on dilute solutions of a covalently linked, slip-stacked terrylene-3,4:11,12-bis(dicarboximide) (TDI) dimer. This dimer undergoes efficient SF in nonpolar 1,4-dioxane and symmetry-breaking charge separation in polar dichloromethane. The various 2DES spectral features in 1,4-dioxane show different pump wavelength dependencies, supporting the presence of mixed states with variable 1 (S 1 S 0 ), 1 (T 1 T 1 ) and CT contributions that evolve with time. Analysis of the 2DES spectra in dichloromethane reveals the presence of a state having largely 1 (T 1 T 1 ) character during charge separation. Therefore, the 1 (T 1 T 1 ) multiexciton state plays an important role in the photophysics of this TDI dimer irrespective of solvent polarity.

Original languageEnglish
Pages (from-to)17907-17914
Number of pages8
JournalJournal of the American Chemical Society
Volume140
Issue number51
DOIs
Publication statusPublished - Dec 26 2018

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Two-Dimensional Electronic Spectroscopy Reveals Excitation Energy-Dependent State Mixing during Singlet Fission in a Terrylenediimide Dimer'. Together they form a unique fingerprint.

  • Cite this