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This review is devoted to the features of isomerization reactions of indoline spiropyrans and the possibilities for their applications as building blocks in the design of molecular machines and ensembles capable of self-organization. Nanoscale systems functioning on the base of changes in geometric parameters and molecular dipole moment when switching between the spirocyclic and merocyanine forms have been considered. The factors that alter the system morphology may be electromagnetic irradiation or the acidity of the medium.

New indoline spiropyran was synthesized by the cyclocondensation of 5-chlorine-substituted Fischer base with 2,7-dihydroxy-1-naphthaldehyde. This spiropyran was used to prepare a new derivative of α-lipoic acid with potential biological activity, which can be considered as a promising photopharmacological agent. The structures of the synthesized compounds were determined by NMR and IR spectroscopy and mass spectrometry and were confirmed by X-ray diffraction. Biological assays using HeLa cells showed that the spirocyclic compounds possess low cytotoxicity even at relatively high concentrations.

The review is devoted to mechanically sensitive indoline spiropyrans and their structural features. Recent advances in the study of their isomerization processes are considered, special attention is paid to the effect of pressure on the behavior of spiropyrans in the composition of various photochromic materials and dyes, as well as in the process of the formation of J-aggregates in Langmuir–Blodgett films.