Hydroxystilbene isomer-specific photoisomerization versus proton transfer

Frederick D. Lewis*, Elizabeth M. Crompton

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


The ground- and excited-state acidities of 3- and 4-hydroxystilbene have been investigated in aqueous solution. Approximate pKa* values determined from the Förster equation are similar for the two isomers; however, 3-hydroxystilbene behaves as a photoacid in water, whereas 4-hydroxystilbene does not. Singular value decomposition with self-modeling is used to obtain more accurate pKa* values for 3-hydroxystilbene. The different behavior of the isomeric hydroxystilbenes is attributed to differences in their excited-state C=C torsional barriers. 3-Hydroxystilbene has a high barrier and a long singlet lifetime, permitting proton transfer to compete with other singlet decay pathways, whereas 4-hydroxystilbene has a low barrier, and thus proton transfer cannot compete with C=C torsion.

Original languageEnglish (US)
Pages (from-to)4044-4045
Number of pages2
JournalJournal of the American Chemical Society
Issue number14
StatePublished - Apr 9 2003

ASJC Scopus subject areas

  • General Chemistry
  • Biochemistry
  • Catalysis
  • Colloid and Surface Chemistry


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