A prominent bathochromic shift effect of indole-containing diarylethene derivativesElectronic supplementary information (ESI) available: Supplementary figures. CCDC 763075. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4ob02619e

The potential implication of photochromic materials with absorption and reactivity in the near-infrared region is far-reaching. In this work, three novel bisindole-containing diarylethene derivatives 1o-3o have been successfully synthesized and their photochromic behaviour exhibits a strong bathochromic shift effect compared with bisbenzothiophene diarylethene 4o . These new bisindole-diarylethene compounds 1o-3o are highly sensitive to photo-stimuli both in solution and in poly(methyl methacrylate) films. Besides, 1o-3o exhibit an excellent reversible fluorescence switching behavior modulated by optical stimuli. Bisindole diarylethene derivatives exhibit a strong bathochromic shift effect in photochromism compared with bisbenzothiophene diarylethene.