Photo-controlled bipolar absorption switches based on 5-dimethylamino substituted indoline spiropyrans with semipermanent merocyanines

Methods of synthesis have been developed to obtain new spiropyrans of the indoline series with semipermanent merocyanines bearing the 5-dimethylamino group in the indoline part and diphenyloxazole, benzoxazole and benzothiazole moieties in the naphthopyran part. In solution, the obtained compounds show both positive and negative photochromism. Photo-controlled bipolar absorption switches based on dimethylamino-substituted spiropyrans have been proposed. Tuning of the characteristics of such switches can be performed both by the structural design of the spiropyran molecules and by the parameters of the medium.