Wavelength and solvent independent photochemistry: the electrocyclic ring-closure of indolylfulgides

Photochem Photobiol Sci. 2009 Apr;8(4):528-34. doi: 10.1039/b817627b. Epub 2009 Feb 11.

Abstract

A wavelength and solvent dependent study of a photochromic indolylfulgide is presented. The ring-closure reaction is characterized using stationary and time-resolved spectroscopy with femtosecond time resolution. After excitation into the first excited singlet state (S(1)) the photoprocesses proceed on ultrafast timescales (0.3-0.45 ps) in both polar and non-polar solvents. Excitation into higher electronic states results in similar reaction kinetics as found for S(1) excitation. A simple kinetic scheme can be established for the photoprocesses under all different experimental conditions: as expected from organic textbooks neither the solvent surroundings nor the excitation wavelength strongly alter the reaction scheme. The experimental study demonstrates that the ring-closure reaction of photochromic indolylfulgides can be considered as a very robust photoprocess: this fact may lead to a great variety of different applications where the reaction dynamics of the molecular switch are not disturbed by any surrounding effects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Indoles / chemistry*
  • Isomerism
  • Kinetics
  • Light
  • Models, Molecular
  • Photochemistry / methods*
  • Quantum Theory
  • Solvents*
  • Spectrometry, Fluorescence
  • Spectrophotometry
  • Spectrophotometry, Ultraviolet

Substances

  • Indoles
  • Solvents