Synthesis and structural characterization of new spiropyran containing conjugated vinyl-3 Н -indolium moiety and its hydrolysis product

new spiropyran containing a cationic 3 Н- indolium substituent and methoxy groups at positions 5 and 5” of the indoline cycles was synthesized. Hydrolysis of this compound was observed during crystallization from EtOH, leading to the formation of protonated merocyanine form of spiropyran containing a free formyl group. The hydrolysis product was characterized by X-ray structural analysis, the intermolecular interactions in crystal were studied with the CrystalExplorer 21.5 software suite. Quantum-chemical modeling based on the Fukui function distribution was used to establish the preferred site for nucleophilic attack, and a mechanism for hydrolysis was proposed.