Gating the photochromism of an azobenzene by strong host–guest interactions in a divalent pseudo[2]rotaxane

Abstract

The ability of an E-configured azobenzene guest to undergo photoisomerisation is controlled by the presence of a complementary host. Addition of base/acid allowed for a weakening/strengthening of the interactions in the divalent pseudo[2]rotaxane complex and hence could switch on/off photochromic activity.