Tunable fluorescent pyrene/diarylethene-based bistable [3]rotaxane

Abstract An adjustable pyrene/diarylethene-based bistable [3]rotaxane driven by acid-base has been successfully developed through “threading-followed-by-stoppering” strategy, exhibiting adjustable photochromic characteristic and tunable fluorescence photoswitching behavior. In this system, the shuttling motion of two macrocyclic host along the axle with four recognition sites effectively controls the distance between the rings and diarylethene (DAE) framework, leading to accurately adjustable photochromic performance through the restriction and relaxation of host rings to DAE. Crucially, the above intelligent behaviors further induce regularly controllable photo-responsive energy transfer-based fluorescent switching performance. The present results may provide a new perspective for directional improvement of fluorescence photoswitching performance.