Synthesis, photo and acidochromic properties of spiropyran-containing methanofullerenes

Spiropyran-containing methanofullerenes able to rapidly and reversibly respond to optical and chemical stimuli were synthesized for the first time by the Bingel–Hirsch reaction and catalytic cycloaddition of diazo compounds to carbon clusters. The effects of substituent structure in the new hybrid molecule and the mode of spiropyran attachment to fullerene on the spectral kinetic properties and photo- and acidochromic behavior of the synthesized fullerene derivatives was established.