Luminescence properties of a thermal-responsive organogel to various metal cations

• A new gelator can form a thermal-responsive gel in ethylene glycol (EG) or the mixture solution of EG and DMF.
• Different fluorescence behaviors were observed upon addition of different metal ions onto the fore-prepared gels.
• The state transition from gel to clear solution can be induced upon addition of Al3 + which can give a brilliant blue emission.
• The gelating ability of the gelator can still be maintained after addition of Mg2 +.
• The Mg2 +-ion-mediated organogel in EG can enhance the fluorescence of GL.

A new gelator (L) containing Schiff base, benzoimidazol and naphthayl moieties was synthesized and its self-assembly was investigated in various solvents. Gelation test revealed that it could form a thermal-responsive gel in ethylene glycol (GL) or the mixture solution of ethylene glycol and DMF. Different fluorescence behaviors were observed upon adding different metal ions. The addition of Mg2 + maintained the gelating ability of L, meanwhile the Mg2 +-ion-mediated organogel in ethylene glycol can enhance the fluorescence of GL. The addition of Al3 + can destroy GL and lead to a state transition from gel to clear solution; the solution can give a brilliant blue emission excited at 365 nm UV. Interestingly, the luminescence of GL increased sharply at first but decreased finally. The fluorescence of GL was quenched when other metal cations were added.

A thermal-responsive organogel can be obtained in ethylene glycol and its self-assembly was investigated in various solvents. The organogel shows unique behavior upon adding Al3 + in comparison to other metal cations. The results show the addition of Al3 + can destroy the gel and lead to a state transition from gel to clear solution; the solution can give a brilliant blue emission excited at handheld 365 nm UV lamp, interestingly the luminescence of gel increases sharply at first but followed by a decrease finally.Figure optionsDownload as PowerPoint slide