Photoisomerization of 2-(2-Hydroxyphenyl)benzothiazole Derivatives as an Adequate Model to Reveal Photochromism of Schiff Bases in the Solid State

Photochromic behavior of 2-(2-hydroxyphenyl)benzothiazole derivatives, whose photoinduced deformation was restricted by the cyclic structure, was first observed to suggest the existence of a cis-keto form as a certain structure for the photochrome of N-salicylideneanilines in the crystal state.