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81.
O. V. Sizova A. I. Panin V. I. Baranovskii N. V. Ivanova 《Journal of Structural Chemistry》1996,37(2):181-191
Semiempirical INDO-E/S+RCIP calculations of the electronic structures of the ground and excited states of the pyrazine (pz)
molecule and [Ru(NH3)5pz]q (q=+1, +2, +3) complexes were performed to analyze the dependence of the calculation results on the active MO space and configuration
basis set. Recommendations for the construction of the {Фk} basis sets and formation of the {ϕk} sets are given.
St. Petersburg State University. Translated fromZhurnal Struktumoi Khimii, Vol. 37, No. 2, pp. 206–219, March–April, 1996.
Translated by I. Izvekova 相似文献
82.
Yu. B. Zelechonok L. P. Ivanova V. V. Zorin S. A. Kotlyar S. S. Zlotskii D. L. Rakhmankulov 《Chemistry of Heterocyclic Compounds》1988,24(1):64-65
Homolytic alkylation of protonated quinoxaline with 18-crown-6, initiated by the system pivalic acid-iron(II) sulfate at 20–25C, gives (quinoxalin-2-yl)-18-crown-6 in 85% yield. Under analogous conditions, the reaction with quinoline affords two isomers: (quinolin-4-yl)-18-crown-6 and (quinolin-2-yl)-18-crown-6, in yields of 20 and 30% respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–76, January, 1988. 相似文献
83.
The reactions of (lithiomethyl)furazans with chlorosilanes were investigated and a number of silyl derivatives of methylfurazans were prepared. The reactivity of these compounds was studied. 相似文献
84.
Dependences of the surface tension of aqueous solutions of cationic (dodecylpyridinium bromide) and nonionic (Tween 80, Triton X-100) surfactants and their mixtures on total surfactant concentration and solution composition were studied. The values of critical micellization concentration (CMC) and excess free energy of adsorption were determined from tensiometric measurements. Based on Rubingh–Rosen model (approximation of the theory of regular solutions), the compositions of micelles and adsorption layers at the solution–air interface as well as parameters of interaction between the molecules of cationic and nonionic surfactants were calculated for the systems indicated above. It was established that, in the case of surfactant mixtures with considerable difference in the CMCs, the micelles of individual surfactant with lower CMC value are formed. The effect of negative deviation from the ideality during the adsorption of surfactants from mixed solutions at the solution–air interface was disclosed. It was shown that the interaction energy depends significantly on the composition of mixed systems. 相似文献
85.
Summary A highly sensitive method for detection of gold, almost free from interferences, is described. The reaction is performed on a short column of anion-exchange resin Dowex 1 X8 (100–200 mesh) in iodide form. To the test solution containing 0.13g/ml of gold(III) is added Sb-solution (weight ratio Au: Sb=1 200) and the mixture is then passed through the resin, followed by 1N NaOH. A crimson colour appearing within 2–3 min indicate gold. Many metal ions, including Pt-metals, Tl(I), Tl(III), Ir(IV), In (III), Ga(III), Cu(II), Cd(II), Zn(II), Pb(II), Fe(III), Mn(II), Co(II), Ni(II), Hg(II), As(III) do not interfere. In the presence of 50-fold excess of Ag(I) or Bi(III) there is no colour because of the formation of a precipitate on the resin.
Zusammenfassung Ein hochempfindliches und selektives Verfahren zum qualitativen Gold-nachweis wurde vorgeschlagen. Die Reaktion wird in einer 10 mm hohen Anionenaustauschersäule Dowex 1 X8 in Jodidform durchgeführt. Zu der aufgetragenen Probelösung fügt man Sb(III) und (V) (im Verhältnis Au: Sb= 1 200) und versetzt nachher auf der Säule mit 1-n NaOH. Nach einigen Minuten entsteht um die Harzkörner eine himbeerrote Färbung. Pt-Metalle, Tl(I), Tl(III), Ir(IV), In(III), Ga(III), Cu(II), Cd(II), Zn(II), Pb(II), Fe(III), Mn(II), Co(II), Ni(II), Hg(II), As(III) stören nicht; Ag(I) und Bi(III) stören gleichfalls nicht, solange sie in nicht mehr als 50facher Menge neben Gold vorliegen. Bei höheren Konzentrationen setzen sie sich als unlösliche Jodide um die Harzkörner ab und stören. Die Nachweisgrenze der Reaktion liegt bei 0,13g/ml.相似文献
86.
T. M. Ivanova M. I. Bazanov A. V. Petrov R. V. Linko K. M. Dyumaev 《Russian Journal of Inorganic Chemistry》2006,51(12):1945-1948
The electronic structure of cobalt complexes with bi-, tri-, and tetradentate ligands and the mutual influence of ligands in them have been studied by X-ray photoelectron spectroscopy. The Co2p, N1s, and O1s photoelectron spectra have been studied. Unlike low-spin Co(III) complexes, the high-spin Co(II) compound exhibits a strong satellite line in the Co2p spectrum. For the high-spin Co(II) compound having unpaired 3d electrons, the Co2p 1/2-Co2p 3/2 spin-orbit splitting is larger than that in the low-spin Co(III) complexes. All cobalt complexes under consideration contain strongly bound dioxygen, which can be considered an inherent structural unit. 相似文献
87.
Akhmetvaleev R. R. Shavaleeva G. A. Ivanova N. A. Miftakhov M. S. 《Russian Journal of Organic Chemistry》2003,39(10):1493-1496
2,3-Dichloro- and 2,3,5-trichloro-4,4-ethylenedioxy-2-cyclopentenones react with allyl and benzyl alcoholates and thiolates and benzylamine to give products resulting from AdNE substitution of the 3-chlorine atom, [1,3]-sigmatropic rearrangement, and cleavage of the C1-C2 bond. 相似文献
88.
The extraction of aluminium and gallium into a molten commercial C17–C20 fatty acid mixture without and with addition of di-2-ethylhexylphosphoric acid (DEHP) is described. Almost quantitative extraction is achieved within 3 min at about pH 1 with 0.15–0.6 mol l?1 DEHP in the fatty acid mixture for organic/aqueous phase ratios of 1:5–1:100. The solidified melts are suitable for x-ray fluorescence spectrometry. The method is appropriate for waste-waters. 相似文献
89.
G. V. Ponomarev B. V. Rozynov T. A. Babushkina T. M. Ivanova 《Chemistry of Heterocyclic Compounds》1975,11(11):1293-1298
Treatment of porphyrins or their copper complexes containing meso-dimethylaminomethyl or meso-dimethylformaldimino groups with lithium borohydride or diborane leads to the corresponding aminoborane derivatives. The reaction of the aminoboranes with trifluoroacetic acid was investigated, and trifluoroacetoxyborane complexes were isolated. 相似文献
90.
The known triterpene tetraoside holothurin A has been isolated from the Pacific Ocean holothurianHolothuria squamifera. By using two independent methods — enzymatic cleavage and two-stage Smith degradation — 22,25-epoxyholost-9(11)-ene-3,12,17-triol, C30H46O6, which is the native aglycone of holothurin A, was obtained. The structure of the native aglycone has been established on the basis of the results of IR, mass, and PMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 448–451, July–August, 1984. 相似文献