A photochromic naphthopyran system in which both optical density and fading speed of colored forms are significantly increased has been described. 3-Aryl-3-(α-naphthalene)-3H-naphtho[2,1-b]pyrans showed thermal stability, and a large optical density of colored forms was obtained at ambient temperature. By attachment of an alkoxyl group to the α-naphthalene group, the fading speed of colored forms was dramatically increased, and the fading speed was increased with increase of the length of alkoxyl chain. The generic nature of the system is beneficial for both the design of naphthopyran molecules with large optical density and fast fading speed at ambient temperature and applications.
研究人员描述了一种光致变色
萘系化合物,在这种化合物中,有色形式的光密度和褪色速度都显著提高。3 芳基-3-(α-
萘)-3H-
萘并[2,1-b]
吡喃具有热稳定性,在环境温度下可获得较大的有色光密度。通过在α-
萘基团上连接烷
氧基,有色形式的褪色速度大大加快,而且褪色速度随着烷
氧基链长度的增加而加快。该体系的通用性既有利于设计光密度大、在常温下褪色速度快的
萘分子,也有利于其应用。