title: A novel smart supramolecular organic gelator exhibiting dual-channel responsive sensing behaviours towards fluoride ion via gel-gel states.
abstract: A novel smart supramolecular organic gelator G-16 containing anion and metal-coordination ability has been designed and synthesized. It shows excellent and robust gelation capability as a strong blue fluorescent supramolecular organic gel OG in DMF. Addition of Zn(2+) produced Zn(2+)-coordinated supramolecular metallogel OG-Zn. Organic gel OG and organometallic gel OG-Zn exhibited efficient and different sensing behaviors towards fluoride ion due to the variation in self-assembling nature. Supramolecular metallogel OG-Zn displayed specific selectivity for fluoride ion and formed OG-Zn-F with dramatic color change from blue to blue green in solution and gel to gel states. Furthermore after directly addition of fluoride into OG produced fluoride containing organic gel OG-F with drastically modulation in color from blue to greenish yellow fluorescence via strong aggregation-induced emission (AIE) property. A number of experiments were conducted such as FTIR, (1)H NMR, and UV/Vis spectroscopies, XRD, SEM and rheology. These results revealed that the driving forces involved in self-assembly of OG, OG-Zn, OG-Zn-F and OG-F were hydrogen bonding, metal coordination, π-π interactions, and van der Waal forces. In contrast to the most anion responsive gels, particularly fluoride ion responsive gels showed gel-sol state transition on stimulation by anions, the gel state of OG and OG-Zn did not show any gel-to-sol transition during the whole F(-) response process.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 610023, PR. China. wtong@dlut.edu.cn ninggl@dlut.edu.cn.
authors.forename: Hassan
authors.initials: H
authors.lastname: Mehdi
authors.forename: Hongchang
authors.initials: H
authors.lastname: Pang
authors.forename: Weitao
authors.initials: W
authors.lastname: Gong
authors.forename: Manivannan Kalavathi
authors.initials: MK
authors.lastname: Dhinakaran
authors.forename: Ali
authors.initials: A
authors.lastname: Wajahat
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Kuang
authors.forename: Guiling
authors.initials: G
authors.lastname: Ning