Synthesis and photochemistry of photochromic fluorescing indol-2-ylfulgimides

A series of N-substituted, thermally stable, photochromic fluorescing indol-2-ylfulgimides were synthesized, with high yields, from the corresponding fulgides by Lewis acid and hexamethyldisilazane promoted one-pot reaction. The quantum efficiencies of the photoinduced coloration and bleaching processes, in polar and nonpolar solvents, were determined. The fluorescence quantum yields of the colored form as well as the thermal stability and fatigue resistances of the synthesized fulgimides were also determined.