Keto–enol at play: regioisomerism regulated switching in indole-naphthyl Schiff bases

Abstract

Indole-naphthyl Schiff bases studied in this work show the importance of hydroxyl positions on enol (E)–keto (K) emissions, aggregation-induced emission (AIE), and viscosity-dependent emission properties. Single-crystal X-ray diffraction and computational studies provide insights into the structural properties of the tautomeric species. INpOH-1 and INpOH-2 demonstrated potential for distinguishing normal and cancer cells based on their polarity and viscosity sensitivity.