Gelation-induced emission enhancement in a "butterfly"-shaped π-conjugated organogelator and its reversible response to acid/base

In this work, we find that a new "butterfly"-shaped pi-conjugated molecule, namely SY1, has the ability to undergo gelatinization in several solvents. Even though the SY1 moiety is not modified by normal auxiliary groups, the gel formation/dissolution process is reversible for many cycles upon heating and cooling processes, indicating that the gel of SY1 has reliable stability during gelation. Results also demonstrate that the gel of SY1 exhibits bright orange emission with the gelation-induced emission enhancement character. Interestingly, the gel shows reversible response upon acid/base treatment. After addition of normal acid, the gel turns into darker colour and its fluorescence undergoes quenching. Increasing pH value of the system by adding NaOH aq. leads to fluorescence emission recovery. Therefore, SY1 represents a pi-conjugated organogelator without normal auxiliary groups, and exhibits gel-induced emission enhancement as well as reversible response to acid/base. The findings in this work enrich our fundamental understanding of the organogel system. (C) 2017 Elsevier Ltd. All rights reserved.