Energy dissipation processes of single-excited 1-hydroxyfluorenone and its hydrogen-bonded complex with N-methylimidazole

Krisztina Sebok-Nagy, L. Biczók, Akimitsu Morimoto, Tetsuya Shimada, Haruo Inoue

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Effects of solvent, pH and hydrogen bonding with N-methylimidazole (MIm) on the photophysical properties of 1-hydroxyfluorenone (1HOF) have been studied. Fluorescence lifetime, fluorescence quantum yield and triplet yield measurements demonstrated that intersystem crossing was the dominant process in apolar media and its rate constant significantly diminished with increasing solvent polarity. The acceleration of internal conversion in alcohols paralleled the strength of intermolecular hydrogen bonding. The faster energy dissipation from the singlet-excited state in cyclohexane was attributed to intramolecular hydrogen bonding. The pK a of 1HOF decreased from 10.06 to 5.0 on light absorption, and H 3O + quenched the singlet-excited molecules in a practically diffusion-controlled reaction. On addition of MIm in toluene, dual fluorescence was observed, which was attributed to reversible formation of excited hydrogen-bonded ion pair. Rate constants for the various deactivation pathways were derived from the combined analysis of the steady-state and the time-resolved fluorescence results.

Original languageEnglish
Pages (from-to)119-126
Number of pages8
JournalPhotochemistry and Photobiology
Volume80
Issue number1
DOIs
Publication statusPublished - Jul 2004

Fingerprint

Hydrogen
Energy dissipation
Hydrogen Bonding
energy dissipation
Fluorescence
fluorescence
Hydrogen bonds
hydrogen
Rate constants
internal conversion
Toluene
Quantum yield
electromagnetic absorption
Excited states
cyclohexane
deactivation
Light absorption
toluene
Protons
polarity

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biophysics

Cite this

Energy dissipation processes of single-excited 1-hydroxyfluorenone and its hydrogen-bonded complex with N-methylimidazole. / Sebok-Nagy, Krisztina; Biczók, L.; Morimoto, Akimitsu; Shimada, Tetsuya; Inoue, Haruo.

In: Photochemistry and Photobiology, Vol. 80, No. 1, 07.2004, p. 119-126.

Research output: Contribution to journalArticle

Sebok-Nagy, Krisztina ; Biczók, L. ; Morimoto, Akimitsu ; Shimada, Tetsuya ; Inoue, Haruo. / Energy dissipation processes of single-excited 1-hydroxyfluorenone and its hydrogen-bonded complex with N-methylimidazole. In: Photochemistry and Photobiology. 2004 ; Vol. 80, No. 1. pp. 119-126.
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