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Mercaptopropionic Acid (mercaptopropionic + acid)
Selected AbstractsConfigurational assignments of the diastereomers of 3,3,-(1,2-ethanediyl)bis[2-(3-fluorophenyl)-5-methyl-4-thiazolidinone] derivative with four stereogenic centersJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2001Maria Gabriella Vigorita Diastereomers of antiinflammatory/analgesic and antihistaminic 3,3,[(1,2-ethanediyl)bis(2-aryl-4-thiazo-lidinone)] derivatives possessing two stereogenic centers (indicated as BIS 2*C) have been widely investigated in recent years. The 5,5,-dimethyl analogues (BIS 4*C), now reported, have been synthesized by reaction of (±) ,-mercaptopropionic acid and N,N' -di(3-fluorobenzyliden)ethylenediamine. Because the 2 and 2,carbons bear the same groups and similarly the 5 and 5, carbons, and the latter groups are different from the former, four enantiomeric pairs and two meso forms exist in this situation. These diastereomers were identified by the concerted use of nmr spectroscopy and hplc on chiral stationary phase. [source] Surface-enhanced Raman scattering from analytes adsorbed on gold nanoparticles inside polymer beadsJOURNAL OF RAMAN SPECTROSCOPY, Issue 10 2004Mina Larsson Abstract Porous polymer beads with a large inner area were used as a stabilizing matrix for SERS-active gold particles. A commercially available ion exchanger (SOURCETM) was used together with HAuCl4. Absorbance measurements and an x-ray diffraction study confirmed that nanocrystalline gold was obtained in the polymer beads. Transmission electron microscope measurements were performed and showed that larger nanoparticles, 20,100 nm, were obtained on the surface, whereas in the interior smaller particles, approximately 2,10 nm, could be found. Three analytes, mercaptoethanesulfonate, mercaptopropionic acid and thiocyanate, were adsorbed on the gold particles inside the polymer beads. From all analytes enhanced Raman spectra could be obtained. The distribution of analytes adsorbed on gold nanoparticles was investigated by confocal Raman spectroscopy. SERS spectra from the analytes could be observed throughout the polymer bead, indicating a fairly uniform distribution of analytes adsorbed on gold nanoparticles. Copyright © 2004 John Wiley & Sons, Ltd. [source] Preparation of Bismuth Oxide Quantum Dots and their Photocatalytic Activity in a Homogeneous SystemCHEMCATCHEM, Issue 9 2010Prof. Hua Zhang Abstract Colloidal oil-soluble Bi2O3 quantum dots (QDs) are synthesized through an alcoholysis route in organic media. Water-soluble Bi2O3 QDs are then obtained from the initial oil-soluble QDs through phase transfer by surface modification with mercaptopropionic acid. X-ray diffraction and transmission electron microscopy studies show that the crystallinity is enhanced and particles grow larger after phase transfer. The water-soluble Bi2O3 QDs exhibit excellent photocatalytic activity for the degradation of methyl orange at a wide range of pH values. After several cycles, the Bi2O3 QDs retain high degradation efficiency. Simulation according to the first-order reaction dynamics indicates that the degradation reaction may follow complicated quasi-homogeneous photocatalysis. [source] High Sensibility of Quantum Dots to Metal Ions Inspired by Hydroxyapatite MicrobeadsCHINESE JOURNAL OF CHEMISTRY, Issue 6 2010Xiang Wang Abstract An approach for the sensitive and selective determination of Ag+, Cu2+ and Hg2+ ions was developed based on the fluorescence quenching of mercaptopropionic acid (MPA) capped CdTe quantum dots in the existence of hydroxyapatite (HAP) nanoribbon spherulites. Among various metal ions investigated, it was found that the fluorescence of CdTe QDs was only sensitive to Ag+, Cu2+ and Hg2+ ions. The addition of HAP into the CdTe system could bring forward a sensitivity improvement of about 1 to 2 orders of magnitude in the detection of Ag+ and Cu2+ compared with the plain CdTe system without the existence of HAP; while there was no sensitization effect for Hg2+. Under optimal conditions, the detection limits for Ag+, Cu2+ and Hg2+ were 20, 56 and 3.0 nmol·L,1, respectively, and the linear ranges were 0.02,50, 0.056,54 and 0.003,2.4 µmol·L,1, respectively. Mechanisms of both QDs fluorescence quenching by metal ions and the sensitization effect by HAP were also discussed. [source] | ||||||||||