Imaging Science and Photochemistry ›› 2001, Vol. 19 ›› Issue (3): 169-176.DOI: 10.7517/j.issn.1674-0475.2001.03.169

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STUDY ON THE PHOTODEGRADATION MECHANISM OF CYANINE DYES AND MEROCYANINE DYES SOLUTION

YANG Song-jie1, MENG Fan-shun1, TIAN He1, YAO Si-de2   

  1. 1. Institute of Fine Chemicals, East China University of Science &, Technology, Shanghai 200237, P. R. China;
    2. The Laboratory of Radiation Chemistry, Shanghai Institute of Nuclear Research, Chinese Academy of Sciences, Shanghai 201800, P. R. China
  • Received:2000-10-11 Revised:2000-11-07 Online:2001-08-20 Published:2001-08-20

Abstract: The photodegradation kinetics of cyanine dyes and merocyanine dyes were studied by UV-Vis absorption spectroscopy. The results show that the rate of the photofading reactions of the dyes follow quasi-first-order or zero order kinetics in acetonitrile. The main photodegradation products of the dyes were identified by GC/MS spectrometry. Those cyanine dyes holding a positive charge have relative good photostability comparing with merocyanines. The experimental results imply that the photodegradation intermediates for the cyanine dyes may be the semi-oxide-state of dye, Dye+. The transient absorption spectra of Dye+ were measured by nanosecond laser flash photolysis.

Key words: photodegradation, cyanine dyes, merocyanine dyes, flash photolysis

CLC Number: