A multi-stimuli-responsive organogel based on salicylidene Schiff base

A cholesterol-based salicylidene Schiff base derivative CDBHA (cholesterol 2-(3,5-di-tert-butyl-2-hydroxybenzylideneamino)acetate) with excellent multi-stimuli-responsive properties has been designed and synthesized. CDBHA can readily self-assemble into gels with nanofiber structures in several kinds of organic solvents. Compared to their corresponding solutions, the generated gels exhibited a significantly enhanced emission. This typical aggregation-induced emission (AIE) property is a result of the cooperative formation of the J-aggregates and inhibition of the intramolecular rotation. In addition, CDBHA gels are intelligent. On one hand, gel-sol transitions together with noticeable fluorescence changes can be reversibly modulated by alternating rounds of cooling and heating. On the other hand, the gels show a highly selective dual-responsive behavior to Zn2+ through a gel-sol transition, a turn-on of fluorescence and an efficient dual-responsive behavior to F− through gel-sol transition and color changes.