Twisted cucubit14uril, tQ 14, forms a fluorescent supramolecular polymer with the water-soluble fluorescent tetrapyridinium pyrene compound TPYP via host–guest interactions. Binding is via the ...alkyl chains and pyridines of TPYP at a molar ratio of 2:1 (tQ 14:TPYP), and the structure forms a loose and porous supramolecular polymer TPYP-tQ 14. Upon addition of different metals to a solution of TPYP-tQ 14, it was found that Ni2+ significantly reduced the emission of TPYP-tQ 14 and impacted the morphology of the TPYP-tQ 14, changing it from a loose porous structure to a chain. Due to the special structure of tQ 14, the mechanism of regulation is considered to be a coordination interaction between Ni2+ and the third portal of tQ 14. This research makes full use of the structural advantages associated with twisted cucurbitnurils and provides a new method for controlling the structure of a polymer through coordination-type interactions.
An aniline-functionalized naphthalene dialdehyde Schiff base fluorescent probe
with aggregation-induced enhanced emission (AIEE) characteristics was synthesized via a simple one-step condensation ...reaction and exhibited excellent sensitivity and selectivity towards copper(II) ions in aqueous media with a fluorescence " turn-off " phenomenon. The detection limit of the probe is 1.64 × 10
mol·L
. Furthermore, according to the results of the UV-vis/fluorescence titrations, Job's plot method and
H-NMR titrations, a 1:2 stoichiometry was identified. The binding constant between
and Cu
was calculated to be
= 1.222 × 10
. In addition, the AIEE fluorescent probe
could be applied to detection in real water samples with satisfactory recoveries in the range 99.10-102.90% in lake water and 98.49-102.37% in tap water.
Potassium ferricyanide in an aqueous solution is easily decomposed into highly toxic substances (potassium cyanide and hydrogen cyanide) by light or alkaline action, which poses a major hazard to ...environmental and human health. Here, a reticulated aggregation-induced emission (AIE) supramolecular polymer material (TPAP-Mb@tQ14) was prepared by the supramolecular self-assembly of twisted cucurbit14uril (tQ14) and a triphenylamine derivative (TPAP-Mb). TPAP-Mb@tQ14 not only recognizes Fe(CN)6 3– with sensitive specificity with a limit of detection (LOD) of 1.64 × 10–7 M but can also effectively remove and adsorb Fe(CN)6 3– from an aqueous solution with a removal rate as high as 97.38%. Meanwhile, an important component of the supramolecular polymer material (tQ14) can be reused. Thus, the tQ14-based supramolecular assembly has the potential to be used for applications addressing toxic anionic contaminants present in aqueous environments.
In this study, we synthesized a coumarin-hemicyanine-based deep red fluorescent dye that exhibits an intramolecular charge transfer (ICT). The probe had a large Stokes shift of 287 nm and a large ...molar absorption coefficient (ε = 7.5 × 10
L·mol
·cm
) and is best described as a deep red luminescent fluorescent probe with
= 667 nm. The color of probe W changed significantly when it encountered cyanide ions (CN
). The absorption peak (585 nm) decreased gradually, and the absorption peak (428 nm) increased gradually, so that cyanide (CN
) could be identified by the naked eye. Moreover, an obvious fluorescence change was evident before and after the reaction under irradiation using 365 nm UV light. The maximum emission peak (667 nm) decreased gradually, whilst the emission peak (495 nm) increased gradually, which allowed for the proportional fluorescence detection of cyanide (CN
). Using fluorescence spectrometry, the fluorescent probe W could linearly detect CN
over the concentration range of 1-9 μM (
= 9913, RSD = 0.534) with a detection limit of 0.24 μM. Using UV-Vis spectrophotometry, the linear detection range for CN
was found to be 1-27 μM (
= 0.99583, RSD = 0.675) with a detection limit of 0.13 μM. The sensing mechanism was confirmed by
H NMR spectroscopic titrations,
C NMR spectroscopy, X-ray crystallographic analysis and HRMS. The recognition and detection of CN
by probe W was characterized by a rapid response, high selectivity, and high sensitivity. Therefore, this probe provides a convenient, effective and economical method for synthesizing and detecting cyanide efficiently and sensitively.
A series of 2-1-(4,6-dimethyl-2-benzhydrylphenylimino)ethyl-6-1-(arylimino)ethylpyridines was synthesized and used to prepare the iron(II) and cobalt(II) chloride complexes thereof. All organic ...compounds were fully characterized by elemental analysis, IR and NMR ((1)H/(13)C) spectroscopy, whilst the metal complexes were characterized by elemental analysis and IR spectroscopy as well as by single-crystal X-ray diffraction studies (for two representative cobalt complexes), which revealed that the geometry at the metal was either pseudo-square-pyramidal or trigonal bipyramidal. Upon activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all metal complex pre-catalysts exhibited high activities for ethylene polymerization. The iron pre-catalysts show much higher activity than did their cobalt analogues; however, the iron catalytic systems generally produced polyethylene of wide molecular weight polydispersity. At elevated reaction temperature, the polyethylene was of lower molecular weight, but revealed narrow polydispersity.
The efficient and selective detection of isomers is an attractive but challenging area. In this study, a supramolecular fluorescent probe based on cucurbit8uril (Q8) and a pyrene-based derivative (G) ...was prepared, which effectively recognized and removed o-nitrophenol (o-NP) from a mixture of nitrophenol isomers. The newly designed probe G@Q8 was characterized by NMR spectroscopy, fluorescence emission and UV–Vis spectroscopy, and its host-guest properties in aqueous solution were investigated. The results revealed that the system forms a stable inclusion complex with a stoichiometric ratio of 1:1, which was accompanied by a distinct fluorescence enhancement of G. Moreover, it was employed for the rapid detection of nitrophenol isomers where o-NP showed a dramatical quenching efficiency with a detection limit of 1.53 × 10−7 mol·L-1. This highly efficient supramolecular fluorescent probe offers a new strategy for the convenient detection and removal of o-NP from mixtures in aqueous medium.
A supramolecular fluorescent probe based on cucurbit8uril (Q8) and a pyrene-based derivative (G) was prepared, which effectively recognized and removed o-nitrophenol (o-NP) from a mixture of nitrophenol isomers. Display omitted
•A novel supramolecular fluorescent probe based on cucurbit8uril (Q8) and a pyrene-based derivative (G) was prepared.•A fluorescence quenching method for the selective recognition and removal of o-nitrophenol (o-NP) from a mixture of nitrophenol isomers.•This probe allows the quantification of o-nitrophenol at the μM level in the whole aqueous system.
The ligand series 2-1-(2,4-dibenzhydryl-6-methylphenylimino)ethyl-6-1-(arylimino)ethylpyridines and the iron(II) chloride complexes thereof have been synthesized and characterized by elemental and ...spectroscopic analyses. The molecular structures of C1 and C2, determined by single-crystal X-ray diffraction analysis, confirmed a pseudo-square-pyramidal geometry at the iron center. Upon treatment with either MAO or MMAO, all iron pre-catalysts possessed good thermo-stability and exhibited high activities up to 5.22×107gmol−1(Fe)h−1 toward ethylene polymerization, producing highly linear polyethylene products. Optimization of the reaction parameters gave polyethylenes with narrow molecular weight distributions, indicating that single-site active species were formed; the molecular weights of the resultant polyethylenes could also be controlled.
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