- Development of nanomaterial chemosensors for toxic metal ions sensing
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Heavy metal ions are harmful to aquatic life and humans owing to their high toxicity and non-biodegradability, so their removal from wastewater is an important task. Therefore, this work focuses on designing suitable, simple and economical nanosensors to detect and remove these metal ions with high selectivity and sensitivity. Based on this idea, different types of mesoporous materials such as hexagonal SBA-15, cubic SBA-16 and spherical MCM-41, their chloro-functionalized derivatives, as well as 4-(4-nitro-phenylazo)-naphthalen-1-ol (NPAN) azo dye have been synthesized, with the aim of designing some optical nanosensors for metal ions sensing applications. The mentioned azo dye has been anchored into the chloro-functionalized mesoporous materials. The designed nanosensors were characterized using scanning and transmission electron microscopy as well as Fourier transform infrared and UV–visible spectral analysis, nitrogen adsorption–desorption isotherms, low-angle X-ray diffraction and thermogravimetric analyses. Their optical sensing to various toxic metal ions such as Cd (II), Hg (II), Mn (II), Fe (II), Zn (II) and Pb (II) at different values of pH (1.1, 4.9, 7 and 12) was investigated. The optimization of experimental conditions, including the effect of pH and metal ion concentration, was examined. The experimental results showed that the solution pH had a major impact on metal ion detection. The optical nanosensors respond well to the tested metal ions, as reflected by the enhancement in both absorption and emission spectra upon adding different concentrations of the metal salts and were fully reversible on adding ethylene diamine tetra acetic acid or citric acid to the formed complexes. High values of the binding constants for the designed nanosensors were observed at pHs 7 and 12, confirming the strong chelation of different metals to the nanosensor at these pHs. Also, high binding constants and sensitivity were observed for NPAN-MCM-41 as a nanosensor to detect the different metal ions. From the obtained results, we succeeded in transforming the harmful azo dye into an environmentally friendly form via designing of the optical nanosensors used to detect toxic metal ions in wastewater with high sensitivity.
- Fayed, Tarek A.,El-Nahass, Marwa N.,El-Daly, Hosny A.,Shokry, Amal A.
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- Diaryl azo derivatives as anti-diabetic and antimicrobial agents: synthesis, in vitro, kinetic and docking studies
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In the present study, a series of azo derivatives (TR-1 to TR-9) have been synthesised via the diazo-coupling approach between substituted aromatic amines with phenol or naphthol derivatives. The compounds were evaluated for their therapeutic applications against alpha-glucosidase (anti-diabetic) and pathogenic bacterial strains E. coli (gram-negative), S. aureus (gram-positive), S. aureus (gram-positive) drug-resistant strain, P. aeruginosa (gram-negative), P. aeruginosa (gram-negative) drug-resistant strain and P. vulgaris (gram-negative). The IC50 (μg/mL) of TR-1 was found to be most effective (15.70 ± 1.3 μg/mL) compared to the reference drug acarbose (21.59 ± 1.5 μg/mL), hence, it was further selected for the kinetic studies in order to illustrate the mechanism of inhibition. The enzyme inhibitory kinetics and mode of binding for the most active inhibitor (TR-1) was performed which showed that the compound is a non-competitive inhibitor and effectively inhibits the target enzyme by binding to its binuclear active site reversibly.
- Tahir, Tehreem,Shahzad, Mirza Imran,Tabassum, Rukhsana,Rafiq, Muhammad,Ashfaq, Muhammad,Hassan, Mubashir,Kotwica-Mojzych, Katarzyna,Mojzych, Mariusz
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p. 1509 - 1520
(2021/07/16)
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- Facile synthesis of 1-naphthol azo dyes with nano Sio2/Hio4 under solvent-free conditions
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Nano-silica supported periodic acid (nano-SPIA) has been utilized as a heterogeneous reagent for a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under solvent-free conditions at room temperature. This method has some advantages, the reaction workup is very easy and the catalyst can be easily separated from the reaction mixture and one-pot procedure. The related products have been obtained in good to excellent yields, high purity and short reaction times. The structures of the products have been characterized by several techniques using UV-Vis, FT-IR, 1H NMR, 13C NMR and mass spectra.
- Bamoniri, Abdolhamid,Pourali, Ali Reza,Nazifi, S. Mohamad Reza
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p. 439 - 445
(2013/12/04)
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- A green alternative to synthetize azo compounds
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Different nitrates were used as sources of nitrosonium ion to obtain diazonium salts. Diverse azo compounds were synthetized in acetonitrile giving very good yields and free of by-products in comparison with traditional synthesis. Among the tested species, the best combination for para red synthesis was nitric acid and gaseous hydrogen chloride.
- Velasco, Manuel I.,Kinen, Claudio O.,Hoyos De Rossi, Rita,Rossi, Laura I.
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experimental part
p. 259 - 264
(2012/01/04)
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- Synthesis of porphyrins with reactive groups on phenyl rings. 8. Azo dyes on tetraphenylporphyrins
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Porphyrins having covalently attached residues of azo dyes on the periphery of the molecule have been synthesized by the diazotization of tetraaminophenylporphyrins and subsequent azo coupling of the diazonium salts with phenol, and with α- and β-naphthols. The possibility of π - π electron interaction of the two chromophoric systems has been studied. 1997 Plenum Publishing Corporation.
- Syrbu,Semeikin,Syrbu
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p. 897 - 901
(2007/10/03)
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- A Simple Route for the Synthesis of Chlorosubstituted Arylazobenzenes, Arylazonaphtalenes, and Arylazopyrazoles
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The reaction of arylazophenoles and arylazohydroxypyrazoles (or their tautomer hydrazones) 10, 11, and 15 with POCl3 in dimethylformamide yields chlorosubstituted arylazobenzenes or arylazopyrazoles 12, 13 and 16, resp., in moderate to high yields.The substitution of the OH-group by the Cl-moiety is favoured by acceptor substituents in the aryl fragments ortho- and/or para-linked to the azo group.In case that arylazocompounds derived from resorcinol are used the substitution reaction runs in a stepwise manner giving raise to the formation of o-hydroxy-p-chlorosubstit uted azo compounds 18 primarily and then of dichlorosubstituted azo compounds 19.
- Guenther, R.,Jaehne, E.,Hartmann, H.,Schulze, M.
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p. 945 - 954
(2007/10/02)
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- BORON PHOTOCHEMISTRY. XV. DETERMINATION OF THE HAMMETT SUBSTITUENT CONSTANT FOR THE p-DIMESITYLBORYL GROUP
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Hammett signal values reflect relative strengths of the combined inductive and resonance effects of substituents.Using the ionization technique, as well as an independent neutralization method, we found the ?H value for the p-dimesitylboryl group to be 0.42 as compared to 0.78 for the p-nitro group.The value of ?uv,H=0.65 +/- 0.03 determined from pi-electron interaction processes, such as absorption spectra and pi complex formation, is felt to relate better to the p-dimesitylboryl-substituted dyes.A similar function reflecting the pi resonance interaction of substituent groups is the Tomasik-Krygowski ?uv,K value, for which 0.58 was found for the p-dimesitylboryl group compared to 0.66 for the p-nitro group.
- Glogowski, M. E.,Williams, J.L.R.
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p. 137 - 146
(2007/10/02)
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