Spiropyran-Merocyanine Equilibrium in Presence of Organic Acids and Bases

ABSTRACT

Manipulation of the rate of thermal reversion of N-functionalized merocyanines (MC) to the corresponding spiropyran isomers in the dark, was demonstrated by using both organic acid and base additives. In the presence of organic bases, increase or decrease of the rate of reaction was dependent on the solvent used. When organic acids were used, in all cases the reaction rate decreased when compared with the system containing no acid. Similar behavior was also observed in polymer films. This approach is of interest for applications in the design of optical switches and memory with enhanced stability of the stored information.

Keywords:

• merocyanine
• optical switch
• spiropyran

Acknowledgments

This work was supported by NSERC, Queen's University and by Xerox Research Centre of Canada.