Pentafluorophenyl Esters as Exchangeable Stoppers for the Construction of Photoactive [2]Rotaxanes

Stable pillar[5]arene-containing [2]rotaxane building blocks with pentafluorophenyl ester stoppers have been efficiently prepared on a multi-gram scale. Reaction of these various nucleophiles gave access to wide range [2]rotaxanes amide, or thioester in good excellent yields. The rotaxane structure is fully preserved during chemical transformations. Actually, the addition-elimination mechanism at work transformations totally prevents unthreading axle moiety mechanically interlocked system. stopper exchange reactions were optimized both solution and under mechanochemical solvent-free conditions. While amide formation more efficient solution, conditions are powerful for transesterification reactions. Starting from fullerene-functionalized pillar[5]arene derivative, this new strategy easy photoactive incorporating C60 two Bodipy stoppers. Despite absence covalent connectivity between fullerene moieties molecular device, through-space excited state interactions evidenced rotaxane.