Photochromism of a novel spiropyran derivative based on calix[4]arenes

A novel spiropyran derivative carrying a calix[4]arene group has been synthesized through incorporating two spirobenzopyran groups into one 1,3-substituent calix[4]arene derivative. Photochromic properties were studied under alternate irradiation of ultraviolet light and visible light in acetonitrile. Addition of metal ions (such as Mg2C, Ca2C, Eu3C) decreased the first-order thermal decoloration rate constants to different extent. The colored forms of the compound are more stable than the parent 10,30,3-trimethyl-6-nitro-8-methanolspirobenzopyran. It provides a method of increasing stability of the merocyanine forms which are of high importance for applications of photochromic materials, especially in the presence of Eu3C. The compound may be applied as photochromic materials for its high thermal stability of colored forms. q 2005 Elsevier B.V. All rights reserved.