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Synthesis, spectroscopic characterization and antimicrobial evaluation of some (E)-N-(4-substitutedbenzylidene)-4-fluorobenzenesulfonamides

100%
Jayanthi P., Jesu Retna Raj G., Sekar M., Thanikachalam V.
World News of Natural Sciences
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2017
|
vol. 13
101-112
EN
In the present study, six numbers of Schiff bases (1-6) have been synthesized by the condensation of 4-fluorobenzenesulfonamide and substituted aromatic aldehyde. The purities of these Schiff bases have been checked by their physical constants, IR, 1H NMR and 13CNMR spectral data. The antimicrobial activities of these Schiff bases have been evaluated using Bauer-Kirby method.
2
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Theoretical studies on the electronic structures and spectra of single silicon-doped SWCNTs

100%
Gao P., Yu Y., Ni Z., Teng Q.
Open Chemistry
|
2010
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vol. 8
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issue 3
587-593
EN
The equilibrium geometries and electronic structures of a series of SWCNTs doped with a silicon atom were studied by using density function theory (DFT). The most stable doping site of silicon predicted at B3LYP/6-31G(d,p) level was located near the boundary of the SWCNTs. The energy gaps of (3,3) C48, (3,3) C60 and (3,3) C72 were respectively decreased by 0.43, 0.25 and 0.14 eV after doping. Based on the B3LYP/6-31G(d) optimized geometries, the electronic spectra of the doped SWCNTs were computed using the INDO/CIS method. The first UV absorption at 973.9 nm of (5,5)-Si(L) (C59Si) compared with that at 937.5 nm of (5,5) (C60) was red-shifted. The 13C NMR spectra and nuclear independent chemical shifts (NICS) of the doped SWCNTs were investigated at B3LYP/6-31G(d) level. The chemical shift at 119.4 of the carbon atom bonded with the silicon atom in (3,3)-Si(L) (C59Si) in comparison with that at 144.1 of the same carbon atom in (3,3) (C60) moved upfield. The tendency of the aromaticity (NICS = −0.1) for (3,3)-Si(H) (C47Si) with respect to that of the anti-aromaticity (NICS = 6.0) for (3,3) (C48) was predicted. [...]
3
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Growth kinetics of CdSe nanoparticles synthesized in reverse micelles using bis(trimethylsilyl) selenium precursor

86%
Emin S., Dushkin C., Nakabayashi S., Adachi E.
Open Chemistry
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2007
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vol. 5
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issue 2
590-604
EN
We first focus on the kinetics of nanoparticle growth in a microemulsion synthesis of CdSe semiconductor nanocrystals. The process consists of a fast initial stage of typical time constant of the order of 103 s followed by a slow stage of time constant of the order of 104s. Growth proceeds similarly to that described for the hot-matrix synthesis of CdSe, underlining the generality of the two-stage growth mechanism, irrespective of the matrix type and synthesis conditions. However, the time constant of each stage in the microemulsion synthesis is much larger than in the hot-matrix one. Also, the ratio between the fast and slow time constant is appreciably bigger. We also prove that larger size reverse micelles, obtained by increasing the water:surfactant ratio, generally lead to larger CdSe nanoparticles. Bis(trimethylsilyl) selenium is the crucial precursor for the CdSe nanoparticle synthesis. An intermediate stage of the chemical reaction limiting the bis(trimethylsilyl) selenium production is described theoretically. [...]
4
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Synthesis of 4-aryloxy-7-nitrobenzofurazan derivatives from 4-chloro-7-nitrobenzofurazan and various phenoxide anions (including pharmaceuticals) in the presence of crown ethers

86%
Bem M., Caproiu M., Stoicescu D., Constantinescu T., Balaban A.
Open Chemistry
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2003
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vol. 1
|
issue 3
260-276
EN
4-Chloro-7-nitrobenzofurazan reacts by nucleophilic substitution with phenoxide anions derived from estriol (2c), ethynylestradiol (2d), phenol (3e), guaiacol (3f), 2,6-dimethoxyphenol (3g), eugenol (3h), isoeugenol (3i), the cytostatic Etoposide (4), and Reichardt’s betaine (5) in the presence of crown ethers affording the corresponding 4-aryloxy-7-nitrobenzofurazan derivatives 6c, 6d, 7e-7i, 8, and 9. The structure of these compounds was confirmed by NMR spectra. Hydrophobicity/hydrophilicity parameters were investigated by reverse phase thin-layer chromatography.
5
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Solid Fly-ash:PTS catalyzed synthesis, spectral studies and antimicrobial activities of some 1,3-diarylpropenones

72%
Arulkumarana R., Vanangamudia G., Kamalakkannana D., Sundararajana R., Vijayakumara S., Thirumurthyb K., Mayavelb P., Thirunarayanan G.
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2012
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vol. 67
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issue 1-2
45-77
EN
The green catalyst Fly-ash:PTS has been prepared and characterized by IR and SEM analysis. Using this catalyst some aryl chalcones have been synthesized by aldol condensation of aryl methyl ketone and substituted benzaldehydes. It has been observed that this reaction yields more than 85% of the product. These chalcones have been characterized by their physical constants and spectral data following the procedures published in literature. The effect of substituents on the spectral data of the chalcones, synthesized, has been studied using single and multi-regression analysis with Hammett equation. The antibacterial and antifungal activities of these chalcones have been studied using Bauer-Kirby method.
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