Multistimuli-Responsive Fluorescent Organogelator Based on Triphenylamine-Substituted Acylhydrazone Derivative

Abstract

A new triphenylamine-based acylhydrazone derivative (TPAH-B8) was synthesized. TPAH-B8 could form organogels in cyclohexane through ultrasonic treatment. A typical gelation-induced fluorescence enhancement property was observed, which was attributed to the formation of J-aggregate in the gel state. More interestingly, TPAH-B8 exhibited multistimuli responsive behaviors. First, TPAH-B8 showed a solvatochromic effect, with the emission color changing from blue to cyan with the change in solvent from nonpolar cyclohexane to polar dimethyl sulfoxide (DMSO). Second, TPAH-B8 showed a reversible mechanofluorochromism. The xerogel of TPAH-B8 emitted a blue fluorescence, while the fluorescence color changed to cyan after grinding. The cyan and blue colors could be repeated with the treatment of grinding and annealing, which was explored and ascribed to the transformation between crystalline and amorphous states. Third, TPAH-B8 revealed acidochromic property. The fluorescence color of TPAH-B8 in organogel and solid states could be switched by trifluoroacetic acid (TFA)/triethylamine (TEA). This work not only demonstrated the multistimuli-responsive fluorescent properties of TPAH-B8 but also offered an easy way to develop new kinds of multistimuli-responsive fluorescent materials.

Organogels versus Hydrogels: Advantages, Challenges, and Applications

“…In the presence of organic solvents, various gelators are able to form stable organogels, metallogels, and xerogels owing to the self-assembling of π-conjugated networks, as well as hydrogen and van der Waals forces between the moieties and the solvent. [94,95] However, matching these conditions requires the testing of a wide range of solvents with each supramolecular network to describe its functionality, as well as stability conditions and limitations. As an example, Yang et al reported that a coumarin-based Schiffbase gelator forms low-molecular-weight organogel networks in isopropanol, tert-amyl alcohol, n-butanol, and phenylamine, and acts as an ion detector (Figure 5B).…”

A Gelation-Induced Enhanced Emission Active Stimuli Responsive and Superhydrophobic Organogelator: “Turn-On” Fluorogenic Detection of Cyanide and Dual-Channel Sensing of Nitroexplosives on Multiple Platforms

“…The unique optical patterning and morphological perspectives of π-conjugated self-assembled molecular systems have recently created glimpses of curiosity due to constituting dynamically flexible noncovalent interactions (π ... π, hydrogen bonding, van der Waals forces), which respond sensibly toward various external stimuli (stress, heat, different analytes, etc.) mainly via tunable fluorescence and phase transition. , Among the ubiquitous analytes present in the environment, cyanide (CN – ) and nitroaromatic compounds (NAs) cause momentous ecological pollution via their uncontrolled release into the surroundings by industrial wastages and unauthorized terror activities. Importantly, binding of CN – with iron (Fe 3+ ) in metalloenzyme hampers the central respiratory system of the mammalian body, which ultimately causes instantaneous death .…”

“…mainly via tunable fluorescence and phase transition. 1,2 Among the ubiquitous analytes present in the environment, cyanide (CN − ) and nitroaromatic compounds (NAs) cause momentous ecological pollution via their uncontrolled release into the surroundings by industrial wastages and unauthorized terror activities. Importantly, binding of CN − with iron (Fe 3+ ) in metalloenzyme hampers the central respiratory system of the mammalian body, which ultimately causes instantaneous death.…”

Synthesis and Self-assembly of Novel Nanofeather-like Fluorescent Alkyloxy-Containing Diphenyl Ether Organogelators

“…Biomedical, foodstuff, and cosmetic applications have all exploited organogel technology. − The self-assembly of small organogelator molecules occurs by the entrapment of tolerable volumes of solvents, providing beneficial characteristics for various applications. Self-assembled structures can introduce optoelectronic characteristics like enhancing emission and charge transfer. − A supramolecular organogel can be described as a soft matter consisting of a viscoelastic non-flowing fluid due to the existence of an organogelator capable of self-assembling into three-dimensional supramolecular architectures. Those supramolecular architectures can be generated in a variety of morphologies, such as nanofeathers, nanoribbons, nanosheets, nanorods, and nanofibers. , Self-assembly of organogelators has interesting research in many fields, such as catalysis, sensors, pollutant removal, drug self-delivery, and tissue engineering.…”