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141.
Sodium bromide efficiently catalyses the regioselective cleavage of oxiranes with chlorotrimethylsilane to the corresponding O-silylated chlorohydrins in excellent yields. 相似文献
142.
Hamid Goudarziafshar Ahmad Reza Moosavi‐Zare Zahra Jalilian Mehdi Abdolmaleki 《中国化学会会志》2019,66(5):529-534
Nano‐Zn‐[2‐boromophenyl‐salicylaldimine‐methylpyranopyrazole]Cl2 (nano‐[Zn‐2BSMP]Cl2) as a nanoparticle Schiff base complex and a catalyst was introduced for the solvent‐free synthesis of 4‐((2‐hydroxynaphthalen‐1‐yl)(aryl)methyl)‐5‐methyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐ones by the multicomponent condensation reaction of various aromatic aldehydes, β‐naphthol, ethyl acetoacetate, and phenyl hydrazine at room temperature. 相似文献
143.
Summary
Bis(cyclopentadienyl)titanium(IV) diisothiocyanate [(Cp)2-Ti(NCS)2] reacts with MCl2 (M = Cu, Pd or Pt), [CuCl(PPh3)3], [RuCl2(PPh3)3] and [RuCl2(DMSO)4] (DMSO = dimethylsulphoxide) giving solid compounds of stochiometry [(Cp)2Ti(-NCS)2MCl2] (M = Cu, Pd or Pt), [(Cp)2Ti(-NCS)2CuCl(PPh3)], [(Cp)2Ti(-NCS)2-RuCl(PPh3)2]Cl and [(Cp)2Ti(-NCS)2RuCl2(DMSO)2]. These products have been characterized by physicochemical and spectroscopic methods. 相似文献
144.
A rapid and simple procedure was developed for selective and sensitive determination of ultra‐trace silver in biological and environmental samples using the electrodeposition on a graphite probe modified with palladium followed by electrothermal atomic absorption spectrometry. Several experimental parameters for the electrodeposition, such as deposition potential, electrolyte concentration, pH of solution and deposition time were optimized. The calibration graph after preconcentration was linear in the range of 10‐250 ngL?1 with correlation coefficient of 0.9989 under the optimum conditions for procedure. The limits of detection (LOD) and quantification (LOQ) base on (3σ) and (10σ) were 2.8 ngL?1 and 9.4 ngL?1 respectively. Related standard deviation (RSD) for eight replicate measurements of 100 ngL?1 silver was 4.3%. Samples were digested completely in a closed microwave digestion system using only perchloric acid, and interference owing to various cations was also investigated. The proposed procedure was successfully applied to determine silver in blood, urine and some environmental samples with satisfactory analytical results. 相似文献
145.
H. Ahmad K. Kumar M. A. Rahman M. M. Rahman M. A. J. Miah H. Minami M. A. Nuri 《先进技术聚合物》2013,24(8):740-746
Considering the application potentials of organic materials possessing both conducting and ferromagnetic functions in various electronic devices, an attempt was made to prepare conducting polyaniline (PANI) layered magnetic nano composite polymer particles. Two routes were used to modify magnetic Fe3O4 core particles. In one route, seeded emulsion polymerization of methyl methacrylate (MMA) was carried out in presence of nano‐sized Fe3O4 core particles. In another route, cross‐linker ethyleneglycol dimethacrylate (EGDM) was used in addition to MMA. The modified composite particles were named as Fe3O4/PMMA and Fe3O4/P(MMA‐EGDM), respectively. Finally, seeded chemical oxidative polymerization of aniline was carried out in the presence of Fe3O4/PMMA and Fe3O4/P(MMA‐EGDM) composite seed particles to obtain Fe3O4/PMMA/PANI and Fe3O4/P(MMA‐EGDM)/PANI composite polymer particles. The modification of Fe3O4 core particles was confirmed by electron micrographs, FTIR, UV–visible spectra, X‐ray photoelectron spectra, X‐ray diffraction pattern and thermogravimetric analyses. A comparative study showed that crosslinking of intermediate shell improved the magnetic susceptibility and electrical conductivity of PANI layered magnetic nano composite particles. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
146.
An optimum nanoprecipitation technique for gelatin nanoparticles is established, based on aqueous gelatin solution and ethanolic solution containing stabilizer. Crosslinking with glutaraldehyde results in stable gelatine nanoparticles. Several factors such as the surfactant concentration, type of surfactant, type of nonsolvent and gelatin concentration are evaluated. Gelatin nanoparticles with 200–300 nm can be produced using 20–30 mg mL?1 of gelatin and a minimum of 7% w/v stabilizer (Poloxamer 407 or 188). Furthermore, methanol and ethanol are good nonsolvents, whereas other nonsolvents such as acetone, isopropyl alcohol, and acetonitrile, result in phase separation and visible precipitates. The entrapment efficiency of fluorescein‐isothiocyanate (FITC)‐dextran as model drug was determined to 50% with no substantial effect on particle size. 80% of the drug is only released after enzymatic digestion.
147.
Habibi MH Mokhtari R Mikhak M Amirnasr M Amiri A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1524-1527
Cu(II) and Ni(II) complexes of the general type [M(N2O2)] are described. The N2O2 ligands used are [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine] (HOMeSalpn) and [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,2-diamine (HOMeSalpr). These complexes have been characterized by IR, UV-vis, CV, TG-DTA and 1H NMR spectroscopy. The electrochemical behavior of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Cu(II)-Cu(I) and Ni(II)-Ni(I) is electrochemically irreversible. The new copper complexes have been applied for the preparation of copper nanoparticles using non-ionic surfactant (Triton X-100) by thermal reduction. The copper nanoparticles with average size of 48nm were formed by thermal reduction of [N,N'-bis(2-hydroxy-6-methoxybenzylidene)propane-1,3-diamine]copper(II) in the presence of triphenylphosphine thus releasing the reduced copper and affording the high-purity copper nanoparticles. 相似文献
148.
Adnan J. Al-Rehaily Mohammad S. Ahmad Jamal Mustafa Mai M. Al-Oqail Wafaa H. Hassan Shabana I. Khan Ikhlas A. Khan 《Journal of Saudi Chemical Society》2013,17(1):67-76
Solanopubamine (3β-amino-5α, 22αH, 25βH-solanidan-23β-ol), a steroidal alkaloid was isolated from the alkaloidal fraction of Solanum schimperianum in significant yield. Its structure was established by IR, positive ESI-MS, 1D and 2D NMR. The presence of -3β-NH2 and -23β-OH groups was achieved through methylation, acetylation or coupling with octadecanoic and undec-11-enoic acids to produce six derivatives (2–7). Their structures were confirmed by spectroscopic analyses. Solanopubamine and semi-synthetic analogs are investigated for their in vitro cytotoxicity against a panel of human cancer cell lines and anti-microbial activity. Solanopubamine showed good antifungal activity only against Candida albicans and C. tenuis with MIC of 12.5 μg/mL. Semi-synthesized compounds (2–7) have failed to show anti-tumor and anti-microbial activities. 相似文献
149.
Muhammad Zahid Akbar Ali Omar Ishurd Amir Ahmed Zulfiqar Ali ViqarUddin Ahmad Yuanjiang Pan 《Helvetica chimica acta》2002,85(2):689-697
Two new monodesmosidic cycloartane triterpene glycosides, depressosides E and F, and two new flavonol glycosides, depressonol A and B, were isolated from the butanol‐soluble part of the EtOH extract of Corchorus depressus L . The structures of the new compounds were elucidated as (22R,24S)‐22,25‐epoxy‐9,19‐cyclolanostane‐3β,16β,24‐triol 3‐[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranoside] ( 1 ), (22R,24S)‐22,25‐epoxy‐9,19‐cyclolanostane‐3β,16β,24‐triol 3‐[α‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranoside] ( 2 ), kaempferol 3‐[β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside] 7‐[α‐L ‐arabinofuranoside] ( 4 ), and kaempferol 3‐[β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranoside] 7‐[α‐L ‐arabinofuranoside] ( 5 ) on the basis of chemical evidence and detailed spectroscopic studies. 相似文献
150.
S. Ahmad A. Mannan I. H. Qureshi 《Journal of Radioanalytical and Nuclear Chemistry》1992,157(1):57-63
A radiochemical method for simultaneous determination of toxic elements (Hg, Cd and Sb) in biological materials has been developed. The procedure involves the irradiation of samples with thermal neutrons and quantitative one-step separation in 0.1M 4-(5-nonyl)pyridine/benzene from 2.0M hydrochloric acid followed by gamma-ray spectrometry. The procedure is applied for the analysis and to the studies of distribution of these elements in IAEA-RMs, human serum and hair samples. Results obtained are found to be in good agreement with those reported in the literature. 相似文献