Excitation Localization/Delocalization Isomerism in a Strongly Coupled Covalent Dimer of 1,3-Diphenylisobenzofuran

Schrauben J. N., AKDAĞ A., Wen J., Havlas Z., Ryerson J. L., Smith M. B., ...More

JOURNAL OF PHYSICAL CHEMISTRY A, vol.120, no.20, pp.3473-3483, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 120 Issue: 20
  • Publication Date: 2016
  • Doi Number: 10.1021/acs.jpca.6b00826
  • Journal Name: JOURNAL OF PHYSICAL CHEMISTRY A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3473-3483
  • Middle East Technical University Affiliated: Yes

Abstract

Two isomers of both the lowest excited singlet (S-1) and triplet (T-1) states of the directly para, para'-connected covalent dimer of the singlet-fission chromophore 1,3-diphenylisobenzofuran have been observed. In one isomer, excitation is delocalized over both halves of the dimer, and in the other, it is localized on one or the other half. For a covalent dimer in solution, such "excitation isomerism" is extremely rare. The vibrationally relaxed isomers do not interconvert, and their photophysical properties, including singlet fission, differ significantly.