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31.
Die Verteilung von n-Caprylsäure zwischen organischen Lösungsmitteln und wäßriger Natriumsufatlösung
K. Gloe A. I. Kholkin P. Mühl L. M. Gindin 《Isotopes in environmental and health studies》2013,49(8-9):324-327
Es wurde die Verteilung von n-Caprylsäure zwischen n-Decan, Benzen, Isoamylacetat, Diisopropylketon, Isoamylalkohol und einer wäßrigen 0,6 molaren Natriumsulfatlösung unter Einsatz der 14C-markierten Säure untersucht. Die Verteilungs- und Dimerisationskonstanten für die Reaktionen HR(w) ? HR(org) bzw. 2 HR(org) ? (HR)2(org) wurden bestimmt. Der Einfluß der Lösungsmittel auf die Verteilung der Säure sowie die Bedeutung derartiger Untersuchungen für die Interpretation von Flüssig-Flüssig-Extraktionsgleichgewichten wird diskutiert. 相似文献
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Yu.S. Varshavsky T.G. Cherkasova V.N. Khrustalev V.A. Gindin A.B. Nikol’skii 《Journal of organometallic chemistry》2009,694(18):2917-2922
Trans-[RuPy4(CN)2 cleaves chloro-rhodium bridges in rhodium(I) binuclear complexes, [Rh(CO)2Cl]2, [Rh(Cod)Cl]2, and [(Cod)RhCl2Rh(CO)2] yielding heterometallic triad complexes, [(CO)2ClRh(NC)RuPy4(CN)RhCl(CO)2] (I), [(Cod)ClRh(NC)RuPy4(CN)RhCl(Cod)] (II), and [(Cod)ClRh(NC)RuPy4(CN)RhCl(CO)2] (III), respectively. In solutions, III coexists with equilibrium amounts of I and II in the near-binomial proportions. Under action of [Rh(CO)2Cl]2, II transforms into I with parallel formation of [Rh(Cod)Cl]2. Ligand effect transmission along the L-Rh-NC-Ru-CN-Rh-L′ chain is studied by 1H and 13C NMR. Chemical shifts δ1H and δ13C of Ru-bound Py ligands are sensitive to the nature of Rh-bound ligands. Values of δ1H and δ13C of Cod and 13C of CO ligands are sensitive to the ligands at the remote end of the L-Rh-NC-Ru-CN-Rh-L′ chain. Reaction of trans-[RuPy4(CN)2] with Rh2(OAc)4 yields an apparently linear polymer [-Rh(OAc)4Rh-NCRuPy4CN-]. Upon action of [Rh(CO)2Cl]2, the polymer decomposes yielding I and Rh2(OAc)4. X-ray structure data for I are given. 相似文献
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R. S. Noy V. A. Gindin B. A. Ershov A. I. Kol'tsov V. A. Zubkov 《Magnetic resonance in chemistry : MRC》1975,7(3):109-115
Tautomerism of aromatic β-ketoaldehydes p-XPhCOCH2CHO ( 1 , X = NMe2, OMe, Me, H, Br, NO2), aliphatic β-ketoaldehydes and benzoylacetaldehyde RCOCH2CHO ( 2 , R = Me, i-Bu, t-Bu, Ph), RCOCH(Me)CHO ( 3 , R = Me, Et, i-Pr) and methyl 2-formylpropionate MeOCOCH(Me)CHO ( 4 ) has been studied by the 1H NMR technique. In basic solvents both cis- and trans-enol forms of these compounds co-exist. trans-Enolisation, which occurs exclusively at the formyl group, is most favoured in compound ( 4 ) and least favoured in compounds ( 1 ) and ( 2 ). The increasing electron-attracting property of the substituent X in the aromatic β-ketoaldehydes ( 1 ), as well as increasing solvent basicity in the series propanediol-1, 2-carbonate, acetone < dimethylformamide < dimethylacetamide < pyridine, also shifts the equilibrium towards the trans-enol form. The trans-enol form is absent in aprotic solvents of low basicity such as CCl4, C2HCl3 and toluene. The thermodynamic parameters of the cis-trans-enol (C ? T) and cis-enol-enolic (C ? C') equilibria have been estimated from the temperature dependences. The transition from the cis-to the trans-enol form is accompanied by an entropy decrease of about 10 cal mol?1 degree?1. Nevertheless the trans-enol form is stabilised due to its lower enthalpy. The cis-trans-enol equilibrium is determined by the relative strength of the intramolecular hydrogen bond in the cis-enol form and the intermolecular hydrogen bonds with basic solvent molecules of the trans-enol form. The enthalpy difference of the two cis-enolic forms does not exceed 1.0 kcal/mol, in rough agreement with the data calculated by the CNDO/2 approximation. Polar solvents favour the hydroxymethyleneketone form (C) for both groups of compounds 2 and 3 . The content of the hydroxymethyleneketone form is about the same within series 2 where R = Me, i-Bu, Ph and is a little higher for the t-Bu derivative. A decrease of temperature only slightly shifts the equilibrium of compounds 1 and 2 to the hydroxymethyleneketone form, while in the case of 2-methyl-β-ketoaldehydes (3) this effect is markedly pronounced. 相似文献
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N. Parkansky L. Glikman I. I. Beilis B. Alterkop R. L. Boxman D. Gindin 《Plasma Chemistry and Plasma Processing》2007,27(6):789-797
Electrode erosion was studied in pulsed arcs ignited between two electrodes comprised of 99.99% C (graphite) and 99.5% W submerged
in deionized water or analytical (99.8%) ethanol. In the both cases the erosion rate increased proportionally to the pulse
energy, and the total electrode erosion per unit energy was inversely proportional to the discharge pulse duration. Fifteen
and sixty-μF discharge capacitors were used for formation of the pulses in water. It was obtained that, respectively (a) erosion
of the tungsten anode (Wa) was by factors of 5–6 and ∼10 greater than that of the carbon (Cc) cathode; (b) erosion of the carbon anode (Ca) was by a factor of 1.34 greater and by a factor of 2.65 less than that of the tungsten cathode (Wc); (c) the total erosion rate of both electrodes (anode and cathode) per unit pulse energy for the Wa–Cc pair was greater by factors of 11 and 12.5 than that for the Wc–Ca pair. 相似文献
36.
Summary 1. Structures have been proposed for - and -reolones (Ia and Ib), two spatial isomers isolated by us previously, as 3,4-dimethyl-2-(4-O-methyl-1--resorcyloyl)-8-oxononan-1,4-olides with the trans-diaxial position of the methine protons in the lactone ring, and with the equatorial orientation of the open chain at C4 in -reolone and the axial orientation in -reolone.2. The possibility has been found of converting -reolone in an acid medium into a 7-methoxy-4-oxodihydrocoumarin derivative at the 3-carbon atom.V. L. Komarov Botanical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 30–38, January–February, 1977. 相似文献
37.
The character of the effect of substituents on the position of the keto-enol equilibrium in 2-substituted 4,6-dioxodihydro-1,3-thiazines and the structure of the enol form are examined. 2-Phenyl-4,6-dioxodihydro-15N-1,3-thiazine was synthesized. It was shown by 13C NMR spectroscopy that the 2-phenyl-4-hydroxy-1, 3-thiazin-6-one structure corresponds to the enol form.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 481–484, April, 1979. 相似文献
38.
P. D. Gindin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2010,4(1):22-24
A mathematical model of the process of laser-co ntrolled thermocracking for thin plates of aniso-tropic elastic materials
has been constructed. By means of sequential replacement of the variable scale along one of the orthogonal coordinates, the
problem of determination of the potential has been reduced to the Poisson equation. A comparison with the experiment by the
example of thermocracking of a single-crystal quartz plate in a circumferential direction has been carried out. 相似文献
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