Phototransformation of Pyridine-Containing Nitrosubstituted Spiropyran in the Presence of Metal Ions

Abstract

Photocoloration and complexation reactions of pyridine-containing nitrosubstituted spiropyran with terbium, zinc, and lanthanum cations in acetonitrile have been studied using laser kinetic spectroscopy. The triplet state participates in the photocoloration reaction of spiropyran. The complexation reaction is accompanied by a hypsochromic shift of the absorption band and proceeds in the microsecond range with pseudo-first order rate constants of 1.4 × 10⁶, 2.3 × 10⁶, and 3.5 × 10⁵ s^–1 for lanthanum, zinc, and terbium cations, respectively.