Strong Blue Emissive Supramolecular Self-Assembly System Based on Naphthalimide Derivatives and Its Ability of Detection and Removal of 2,4,6-Trinitrophenol

Abstract

Two simple and novel gelators (G-P with pyridine and G-B with benzene) with different C-4 substitution groups on naphthalimide derivatives have been designed and characterized. Two gelators could form organogels in some solvents or mixed solvents. The self-assembly processes of G-P in a mixed solvent of acetonitrile/HO (1/1, v/v) and G-B in acetonitrile were studied by means of electron microscopy and spectroscopy. The organogel of G-P in the mixed solvent of acetonitrile/HO (1/1, v/v) formed an intertwined fiber network, and its emission spectrum had an obvious blue shift compared with that of solution. By contrast, the organogel of G-B in acetonitrile formed a straight fiber, and its emission had an obvious red shift compared with that of solution. G-P and G-B were employed in detecting nitroaromatic compounds because of their electron-rich property. G-P is more sensitive and selective toward 2,4,6-trinitrophenol (TNP) compared with G-B. The sensing mechanisms were investigated by H NMR spectroscopic experiments and theoretical calculations. From these experimental results, it is proposed that electron transfer occurs from the electron-rich G-P molecule to the electron-deficient TNP because of the possibility of complex formation between G-P and TNP. The G-P molecule could detect TNP in water, organic solvent media, as well as using test strips. It is worth mentioning that the organogel G-P can not only detect TNP but also remove TNP from the solution into the organogel system.

Aggregation‐directed High Fidelity Sensing of Picric Acid by a Perylenediimide‐based Luminogen

“…The XRD pattern of PDI‐1 showed a broad peak centered at 2Q=25.12 (d=3.5 Å) indicating probable π‐π stacking between the PDI cores of the scantily formed loosely bound aggregates as observed in Figure 3B (Figure S13, SI). The PA@ PDI‐1 complex however exhibited a sharp and intense reflection at 2Q=4.76, d=18.24 Å along with relatively less intense peaks for 2Q=9.43, d/2 (9.29 Å) and 2θ=14.43, d/3 (6.13 Å) indicating lamellar organization within the aggregates [37] . Another important peak located at 2θ=26.17, d=3.4 Å corresponding to the interplanar distance between two π‐rings in the lamellar assembly was also observed which further corroborates the induction of an aggregation process.…”

“…To our gratifying surprise, the emission intensity was observed to be rapidly quenched only in presence of PA solution, while the fluorescence intensity remained unaffected for other nitroaromatic compounds (Figure 2A). A probable reason for this high specificity is perhaps the significantly low pKa of PA (0.38) as compared to other similar NACs such as 2,4‐DNP (4.00), 4‐NP (7.16), 2,4‐DNT (17.12), 4‐NT (20.4), etc [37] . The effect of nitro aromatics on the emission of PDI‐1 can also be visualized with naked eyes by simply observing the solutions under UV light (365 nm) as can be seen in Figure 2B (Inset).…”

“…To discern the nature of interaction between PDI‐1 and PA, we took the help of 1 H NMR spectroscopy. In presence of PA, the peaks for the pyridine groups are shifted down‐field (Figure 4A) which may be due to the H‐bonding between the phenolic OH group and the pyridine N atoms [37] . FTIR spectroscopy was then performed to confirm the presence of hydrogen bonding interactions.…”

A Naphthalimide-Benzothiazole Conjugate as Colorimetric and Fluorescent Sensor for Selective Trinitrophenol Detection

“…The compound 1,8-naphthalimide (NPI) has attracted researchers' attention due to its optical and photophysical properties. NPI derivatives have been widely used because of their potential applications in many fields, such as cancer treatment, DNA-targeting binders, supramolecular self-assembly, optoelectronic materials, fluorescent sensors, and living cell imaging [37][38][39][40][41]. As such, the chemistry of NPI is well understood and lends itself to easy modification and manipulation.…”

Preparation of porous polymer materials using water‐in‐oil gel emulsions as templates

“…This property can be attributed to the three‐dimensional network structures that are built up through noncovalent interactions, such as hydrogen bonding, electrostatic interactions, van der Waals interactions and π – π interactions. Although several gelators are already used as hardeners for spilled fluids, cooking oils, cosmetic materials and paint thickeners, recent research on gelators has focused on their application to drug delivery and drug release in the field of biomaterials, scaffold materials for cells in tissue engineering, sensors, templates for the synthesis of inorganic nanostructures, auxiliary agents for producing organic electronics, electrolytes that prevent liquid leakage and detectors for explosives …”