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991.
3-Aminocoumarin (L) has been synthesized and used as a ligand for the formation of Cr(III), Ni(II), and Cu(II) complexes. The chemical structures were characterized using different spectroscopic methods. The elemental analyses revealed that the complexes where M=Ni(II) and Cu(II) have the general formulae [ML(2)Cl(2)], while the Cr(III) complex has the formula [CrL(2)Cl(2)]Cl. The molar conductance data reveal that all the metal chelates, except the Cr(III) one, are non-electrolytes. From the magnetic and UV-Visible spectra, it is found that these complexes have octahedral structures. The stability for the prepared complexes was studied theoretically using Density Function Theory. The total energy for the complexes was calculated and it was shown that the copper complex is the most stable one. Complexes were tested against selected types of microbial organisms and showed significant activities. The free radical scavenging activity of metal complexes have been determined by measuring their interaction with the stable free radical DPPH and all the compounds have shown encouraging antioxidant activities. 相似文献
992.
Nasim Asghari Lalami Hassan Hosseini Monfared Hashem Noei Peter Mayer 《Transition Metal Chemistry》2011,36(6):669-677
Three new binuclear vanadium(V) complexes of bis(aryl)adipohydrazones (H4L1 = bis((2-hydroxynaphthalen-1-yl)methylene)adipohydrazide, H4L2 = bis(5-bromo-2-hydroxybenzylidene)adipohydrazide, and H4L3 = bis(2-hydroxy-3-methoxybenzylidene)adipohydrazide) were synthesized by direct reaction of [VO(acac)2] with the hydrazone ligands. The ligands and complexes were characterized by FT–IR, UV–Vis, and NMR spectroscopic methods.
The crystal structures of the complexes of L1 and L3 were determined by X-ray analyses. The solid-state structure of the complex of L1 features a 1D hydrogen-bonded chain from N⋯H–O hydrogen bonding. The catalytic activities of these complexes have been tested
in the oxidation of various hydrocarbons using H2O2 as the terminal oxidant. Generally, good to excellent conversions have been obtained. 相似文献
993.
Elizabeth Amir Kulandaivelu Sivanandan Justin E. Cochran John J. Cowart Sung‐Yu Ku Jung Hwa Seo Michael L. Chabinyc Craig J. Hawker 《Journal of polymer science. Part A, Polymer chemistry》2011,49(9):1933-1941
The synthesis and characterization of a new family of soluble oligothiophene‐S,S‐dioxides and their use as building blocks to form polythiophene‐S,S‐dioxides via microwave‐assisted Stille coupling polymerization are described. Incorporation of the sulfone group into the polythiophene backbone leads to narrowing of the polymer bandgap, and while the energies of both Frontier orbitals in polythiophene‐S,S‐dioxide are lower with respect to polythiophenes, this tendency is considerably stronger for the lowest unoccupied molecular orbital than for the highest occupied molecular orbital, resulting in greater electron‐accepting ability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
994.
Amir Charkhi Mohammad Kazemeini Seyyed Javad Ahmadi Sareh Ammari Allahyari 《Adsorption》2012,18(2):75-86
Henry??s law constant and crystal diffusivity of xenon in the granulated nano-NaY zeolite were measured by the pulse gas chromatography method. For this purpose the moments of response peaks of xenon were analyzed. The effect of extra column parts of the utilized chromatographic system was also considered by analyzing the moments of the response peak which was obtained by pulse injection of inert gas of helium into the carrier gas of nitrogen. In addition, the measurement of average velocity of the carrier gas regarding the pressure drop in the extra column parts of the system attributed to precise results. By carrying out the experiments at various temperatures in the range of 30?C110?°C the heat of adsorption and activation energy of crystal diffusivity were estimated. In order to find the binder effect on the adsorption of and diffusion into granules, the aforementioned parameters were also measured for the binderless granules of macron sized NaY zeolite. Results revealed that although the adsorption of xenon on the binder of bentonite was negligible, the diffusion resistance created by this binder was significant such that the effective crystal diffusivity in the granules with 25?% binder was determined to be 96 percent lower than the granules with no binder. 相似文献
995.
Mounir Chamam Csilla M. Földváry Arezo M. Hosseini Antal Tungler Erzsébet Takács László Wojnárovits 《Radiation Physics and Chemistry》2012,81(9):1484-1488
Wet oxidation (high-temperature, high-pressure oxidation of organic wastes in aqueous solution) and radiation technology were combined in γ-ray and electron beam induced oxidation of 4×10?4–1×10?2 mol dm?3 Na-phenolate solutions in a wide O2 concentration (1–20 bar pressure) and absorbed dose (0–50 kGy) range. Most experiments were made in stainless steel high pressure autoclave equipped with magnetic stirrer. The rate of oxidation was followed by chemical oxygen demand and total organic carbon content measurements. The rate was similar in γ-ray and pulsed electron beam irradiation and increased with O2 concentration in the liquid. 相似文献
996.
This work aims at reporting the dissociation pressures of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions at different temperatures and various concentrations of inhibitor in aqueous solution. The equilibrium results were generated using an isochoric pressure-search method. These values are compared with some selected experimental data from the literature on the dissociation conditions of hydrogen sulfide and carbon dioxide simple hydrates in the presence of pure water to show the inhibition effects of the above mentioned aqueous solutions. Comparisons are finally made between our experimental values and the corresponding literature data. Some disagreements among the literature data and our data are found. 相似文献
997.
998.
Novel solid-phase microextraction fibers were prepared based on sol–gel technique. Commonly used fused silica substrate was replaced by titanium wire which provided high strength and longer fiber life cycle. Titanium isopropoxide was employed as the precursor which provides a sol solution containing Ti–OH groups and shows more tendencies to the molecularly similar group on the substrate. Three different polymers, poly (dimethylsiloxane) (PDMS), poly(ethylenepropyleneglycol)-monobutyl ether (Ucon) and polyethylene glycol (PEG) were employed as coating polymer in preparing three different fibers. The applicability of these fibers was assessed for the headspace SPME (HS-SPME) of benzene, toluene, ethylbenzene and xylenes (BTEX) from water sample followed by gas chromatography–mass spectrometry (GC–MS). Effects of different parameters such as fiber coating type, extraction condition, desorption condition were investigated and optimized. Under the optimized conditions, LODs and LOQs of 0.75–10 μg L−1 (S/N = 3) and 1–20 μg L−1 (S/N = 10) were respectively obtained. The method showed linearity in the range of 10–25,000 μg L−1 with correlation coefficient of >0.99. The relative standard deviation was less than 8%. 相似文献
999.
A simple, mild, cost-effective, and green approach for the reductive mono-N-alkylation of nitroarenes has been developed. HOAc/Zn are utilized as the reducing system together with a carbonyl compound as an alkyl source in methanol. Excellent yields were obtained with stoichiometric control of mono- over dialkylated products. Application to five complex natural products demonstrated the practical utility of the method. 相似文献
1000.
Piltan M Moradi L Salimi H Zargoosh K Zarei SA 《Combinatorial chemistry & high throughput screening》2012,15(7):571-575
Poly(ethylene glycol) (PEG) has been used as a sustainable, non-volatile, and environmentally friendly reaction solvent for synthesis of functionalized anilines and benzenes via the reaction of malononitrile and β-ketoester derivatives in the presence of activated acetylenes at 80° C. No additional solvent and catalyst are required. 相似文献