Potential application as long-lasting dyes is based on the enhanced stability of the inner portion of the dumbbell-shaped molecule. Studies with cyclodextrin-protected rotaxane azo dyes established this characteristic. More reactive squaraine dyes have also been shown to have enhanced stability by preventing nucleophilic attack of the inner squaraine moiety. The enhanced stability of rotaxane dyes is attributed to the insulating effect of the macrocycle, which is able to block interactions with other molecules.