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.