A novel quinoline-based turn-on fluorescent probe for the highly selective detection of Al (III) and its bioimaging in living cells, plants tissues and zebrafish.

A novel quinoline fluorescent probe QNP ((E)-N'-(5-chloro-2-hydroxybenzylidene) quinoline-2-carbohydrazide) for detection of Al3+ ion was designed, synthesized and characterized. QNP displayed a high fluorescence enhancement in the presence of Al3+ ion in DMF:PBS (99:1, v/v) solution and the detection limit was as low as 1.25 µM with high selectivity and excellent sensitivity from 0 to 3 µM. The sensing ability of QNP towards Al3+ ion is attributed to the synergistic effect of PET and ICT. Furthermore, the binding stoichiometry between QNP and Al3+ ion is of 1:1 by Job's plot and mass spectrum, and the calculated binding constant is 4.29 × 108 M-1. The detection of Al3+ ion in water samples illustrates that QNP could be applied to the detection of practical samples in the environment. Bioimaging experiments on Hela cells, zebrafish and soybean root tissues demonstrate that it has potential application to investigate biological processes involving Al3+ ion within living cells. A quinoline-based turn-on fluorescence probe for the detection of Al3+ and its bioimaging in living cells, plant, and zebrafish.

Solar photodegradation of a textile azo dye using synthesized ZnO/Bentonite.

The present work is devoted to the synthesis of a new photocatalyst ZnO (7.5%)/Bentonite prepared by impregnation method and its successful application for the degradation of Solophenyl Red 3BL (SR 3BL) under solar light (∼660 W/m2). The X-ray diffraction (XRD) indicates mixed phases of the nanocomposite catalyst (ZnO/Bentonite), characterized by scanning electron microscopy, X-ray fluorescence and attenuated total reflection. The optical properties confirm the presence of the Wurtzite ZnO phase with an optical gap of 3.27 eV. The catalyst dose (0.25-1 gL-1), pH solution (2.5-11) and initial dye concentration (5-75 mg/L) are optimized. The optimal pH (∼6.7) is close to the natural environment. The photodegradation yield increases with decreasing the SR 3BL concentration. The equilibrium is reached within 160 min and the data are well fitted by the Langmuir-Hinshelwood model; the SR 3BL disappearance obeys to a first-order kinetic with an apparent rate constant of 10-2 mn-1. The best yield of SR 3BL photodegradation (92%) is achieved for a concentration of 5 mg/L and a catalyst dose of 0.75 gL-1 at free pH.

Efficient one-pot three-component synthesis of N-(4-arylthiazol-2-yl) hydrazones in water under ultrasound irradiation.

A highly efficient and facile one-pot three-component synthesis of N-(4-arylthiazol-2-yl) hydrazones was carried out in excellent yield without any catalyst in water under ultrasound irradiation.

Photoswitchable dynamic combinatorial libraries: coupling azobenzene photoisomerization with hydrazone exchange.

The novel azobenzene-based monomer 1 was prepared, equipped with the necessary functionality to undergo simultaneous dynamic exchange processes: hydrazone exchange and photoisomerization. Acid-promoted hydrolysis of the azobenzene building block produced a dynamic combinatorial library of cyclic oligomers, while multibuilding block libraries were also generated upon addition of proline-based monomers. Libraries equilibrated under thermal conditions were dominated by trans isomers of the azobenzene macrocycles, whereas light-induced isomerization resulted in a conformational change of the library members to their corresponding cis-azo form. In the presence of a pentaproline template, a slower rate of thermal relaxation of the cis-azobenzene species 1(c) was observed, resulting in stabilization and amplification of this receptor due to favorable binding interactions. The facile identification and application of such photoswitchable receptors have the potential to allow for greater control over molecular recognition events.

Microwave assisted condensation reactions of 2-aryl hydrazonopropanals with nucleophilic reagents and dimethyl acetylenedicarboxylate.

The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA) afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times.

[Antiarrhythmic active amidinohydrazones of substituted benzophenones. 4. The photoisomerization of (Z)- and (E)-2-amino-5-chlorobenzophenone amidinohydrazones and the corresponding (E)-N-phenylamidinohydrazone]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 4. Mitteilung: Untersuchungen zur Photoisomerisierung von (Z)- und (E)-2-Amino-5-chlorbenzophenonamidinohydrazon sowie des entsprechenden (E)-N-Phenylamidinohydrazons.

The title compounds undergo a photoisomerization by irradiation. If the E-isomers are irradiated by light of a wavelength of an absorption maximum typical for them, they can be converted quantitatively to the corresponding Z-isomers. In case that the synthesis of analogs of the title compounds give only one configurational isomer, sometimes the missing one can be obtained by photoisomerization.