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排序方式: 共有95条查询结果,搜索用时 31 毫秒
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Rigol C Olea-Azar C Mendizábal F Otero L Gambino D González M Cerecetto H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(13-14):2933-2938
Cyclic voltammetry and electron spin resonance (ESR) techniques were used in the investigation of several potential antiprotozoal thiosemicarbazones nitrofurane derivatives. A self-protonation process involving the protonation of the nitro group due to the presence of an acidic proton in the thiosemicarbazone moiety was observed in the first step of a CEE(rev) reduction mechanism of these derivatives. ESR spectra of the free radicals obtained by electrolytic reduction were characterized and analyzed. AM1 methodology was used to obtain the optimized geometries and UB3LYP calculations were performed to obtain the theoretical hyperfine coupling constants. The theoretical study exhibited an unusual assignment of the spin densities showing a free radical centered in the thiosemicarbazone moiety rather than the nitro which are in agreement with the experimental hyperfine pattern. 相似文献
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S. Petruso S. Caronna S. Gambino G. Filardo G. Silvestri 《Journal of heterocyclic chemistry》1991,28(3):793-796
The electrochemical oxidation of 2,5-diphenyl-3-acetylpyrrole (I) is described. The cyclic derivative 1,6a-dihydro-2,5,6a-triphenyl-3,4-diacetylbenzo[g]pyrrolo[3,2-e]indole (II) was obtained in very good yield. However, when water was present in the reaction medium, a different derivative, 4-acetyl-2-hydroxy-2,5-diphenyl-3-(4′-acetyl-2′,5′-diphenyl-3′-yl)-2H-pyrrole (III) , was obtained as the main product. 2,2′,5,5′-Tetraphenyl-4,4′-diacetyl-3,3′-dipyrryl (IV) , a potentially useful intermediate for the synthesis of condensed pyrroles, was synthesized by zinc reduction of III. 相似文献
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F. Cerdá C. Kremer D. Gambino E. Kremer 《Journal of Radioanalytical and Nuclear Chemistry》1994,186(4):291-301
Electrolytic reduction of pertechnetate was performed in aqueous solution containing -acceptor ligands. Cyanide and 1,10-phenanthroline were the selected ligands. In both cases, electrolyses produced a cathodic TcO2 deposit and soluble Tc complexes. When cyanide was the ligand, the complexes formed were [Tc (CN)6]5– and [TcO2 (CN)4]3–. When working with the amine, [Tc (phen)3]2+ and another positively charged species were found after reaction. Results are compared with previous studies with amines, and the usefulness of the electrolytic route to obtain Tc complexes is evaluated. 相似文献
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G. A. Vaglio O. Gambino R. P. Ferrari G. Cetini 《Journal of mass spectrometry : JMS》1971,5(5):493-503
The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe2(CO)6[C2(C6H5)s2]2, Fe2(CO)6[C2(CH3)2]2 and Fe2(CO)6[C2(C2H5)2]2, the ruthenium compounds Ru2(CO)6[C2(C6H5)2]2, and Ru2(CO)6[C2(CH3)2]2 and the osmium compounds Os2(CO)6[C2(C6H5)2]2, Os2(CO)6[C2HC6H5]2 and Os2(CO)6[C2(CH3)2]2. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds. 相似文献
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The development of mathematical models for the design of controlstrategies for spark ignition automotive engines is described. The objectiveof the models, used for both simulation and optimization analysis, is theprediction of the effects of control strategies on fuel consumption andemissions of a vehicle over arbitrary driving cycles. In order to achievethe best compromise between precision, experimental costs, computationaltime and flexibility, a mixed modelling approach is used, withphenomenological and input-output models integrated within a hierarchicalsystem.Mean value models have been used to describe the most significant dynamiceffects: (i) air flow. (ii) two phases fuel flow in the intake manifold, and(iii) thermal flow in the cylinder walls. Stochastic effects due to sensorsand actuators can be also predicted.Two-zone and multizone thermodynamic models for the prediction ofpressure cycle sub-models for engine emissions (HC, CO, andNO
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and mechanical losses have been developed. Experimentaldesign techniques are also under development to optimize the interactionsbetween experimental analysis and models. Most of the models have beenintegrated in a computer code, used by a major automotive supplier. 相似文献
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Dinorah Gambino Mariana FernándezDiego Santos Gustavo A. EtcheverríaOscar E. Piro Fernando R. PavanClarice Q.F. Leite Isabel TomazFernanda Marques 《Polyhedron》2011,30(7):1360-1366
In the search for gallium bioactive compounds five Ga(III) complexes, [GaIII(L-H)2](NO3), with tridentate salicylaldehyde semicarbazone derivatives as ligands (L) have been synthesized and characterized in the solid state and in solution by different techniques. The crystal structure of [GaIII(L4-H)2](NO3)·2H2O, where L4 is 3-ethoxysalicylaldehyde semicarbazone, was solved by X-ray diffraction methods. The gallium(III) ion is in a distorted octahedral environment, coordinated to two nearly planar and mutually perpendicular 3-ethoxysalicylaldehyde semicarbazonato anions acting as tridentate ligands through their phenol and carbonyl oxygen atoms and their azomethine nitrogen atom. Their biological potential has been explored by evaluating their activity on Mycobacterium tuberculosis, causative agent of tuberculosis, and their cytotoxicity on tumor cell lines. Three different human tumor cell lines were selected that show different degrees of resistance to metallodrugs: ovarian A2780 (low resistance), breast MCF7 (medium resistance) and prostate PC3 (high resistance) cells. Although the complexes have not shown activity on M. tuberculosis, complexation with gallium has led to the enhancement of the cytotoxic potencies of the organic compounds. Those complexes that contain a bromide substituent at the phenolate ring have shown the highest cytotoxicities. In particular, [GaIII(L2-H)2](NO3), where L2 is 5-bromosalicylaldehyde semicarbazone,·has shown a remarkable cytotoxicity on A2780 tumor cell line with an IC50 value of the same order than cisplatin (IC50 Ga-L2 = 2.4 ± 0.3 μM; IC50 cisplatin = 2.0 ± 0.1 μM, 72 h incubation at 37 °C). Interestingly, this complex has also shown moderate cytotoxicity against MCF7 and PC3 cells (IC50 MCF7 = 30 ± 6; IC50 PC3 = 18 ± 3 μM). Therefore, this gallium compound could be considered a promising wide spectrum potential anti-tumor agent. 相似文献