Low Molecular Weight Fluorescent Organogel for Fluoride Ion Detection

The design, synthesis, and the photophysical properties of a Low Molecular Weight Gel (LMWG) based on AB₃ and AB₂ type poly(aryl ether) dendrons with an anthracene chromophore attached through an acylhydrazone linkage are described. The gel is utilized for an efficient ‘naked eye’ detection of fluoride ions (as low as 0.1 equiv with respect to the gelator concentration), through a reversible gel–sol transition, which is associated with a color change from deep yellow to bright red.

DOI: 10.1021/ol201325j

Luminescent micro and nanogel formation from AB3 type poly(aryl ether) dendron derivatives without conventional multi-interactive gelation motifs - New Journal of Chemistry (RSC Publishing)

We report the synthesis, gelation and photophysical properties of luminescent AB₃ type poly(aryl ether) dendron derivatives in the absence of conventional multi-interactive gelation motifs. The gelation process is controlled through employing partial polar solvent milieu, which significantly enhances the propensity of π–π interaction between the aryl units present in the system. The self-assembly leads to unprecedented gelation through entrapping solvent molecules in the fibrillar arrangement of poly(aryl ether) units. The strategy was further utilized to prepare an excimer based photoluminescent gel through incorporating anthracene units in the dendrons. The close proximity between the anthracene units in the gel renders the formation of anthracene excimers at room temperature, resulting in the emission of bright green light from the gel, upon UV excitation. The study suggests that the size and packing of the self-assembled fibre can be controlled by the generation and functional groups present in the dendron. Furthermore, the strategy envisages an easy approach to generate fluorescent Low Molecular-mass Organic Gelator (LMOG) through incorporating poly cyclic aromatic hydrocarbon units to the poly(aryl ether) dendrons, since the self-assembly is largely guided by π–π interactions.

DOI: 10.1039/C1NJ20136K