Photochromic properties of a vacuum-deposited film of (E)-dicyclopropylmethylene-(2,5-dimethyl-3-fyrylethyldiene)- succinic anhydride

A yellow-orange film was prepared by vacuum deposition technique under a pr essure of 1 x 10(-4) Pa and a boat temperature of 300 degreesC. Upon irradi ation with UV light (366 mn), the yellow-orange film was turned violet, the later color was switched back to the original pail yellow color. When the film was irradiated with light posses a wavelength more than 500 mu. The co loration process was lost when the film was annealed at 80, 100 and 120 deg reesC. The rate constant of the coloration process was determined to be 9.8 x 10(-4) s(-1). (C) 2001 Elsevier Science B.V. All rights reserved.