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21.
Catalytic properties of trinuclear thio complexes of rhenium in hydrogenation of m-nitrobenzoic acid
V. M. Belousov T. A. Pal'chevskaya S. V. Volkov V. L. Kolesnichenko L. V. Bogutskaya S. P. Sharavskaya 《Theoretical and Experimental Chemistry》1993,28(3):194-196
Trinuclear thio complexes of rhenium based on Re3S7 and Re3S4 cluster groupings have been synthesized and studied as catalysts in liquid-phase hydrogenation of m-nitrobenzoic acid. Thio complexes containing as Re3S7 cluster surrounded by hydroxo groups are the most active. Complexes with an Re3S4 cluster are less active. Reversible Re3S7 Re3S4 + S8 transitions were found to be possible in solution.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 3, pp. 239–242, May–June, 1992. 相似文献
22.
A.G. Volkov M.I. Gugeshashvili A.F. Mironov L.I. Boguslavsky 《Journal of Electroanalytical Chemistry》1982,141(5):551-558
The redox reaction between the ferric complex of hydrophobic porphyrin and sodium dithionite in two different phases occurring at the interface between two immiscible liquids has been investigated by Volta potential measurements and spectroscopy. The reduction of the ferric complex of hydrophobic porphyrin adsorbed at the interface was found to be accompanied by a potential shift in the negative direction and to depend significantly on the nature of the anion and the ionic strength of the supporting electrolyte. Specifically adsorbed halogen anions inhibited the redox reaction in the sequence: Cl?, Br?, I?. Depending on pH, the ferric complex of hydrophobic porphyrin exists in the uncharged (FeP-O-PFe) form or in the cation FeP+ form. The interaction between the ferric complex hydrophobic porphyrin and water has also been investigated. 相似文献
23.
Vladimir L. Kolesnichenko Victor B. Rybakov Leonid A. Aslanov Sergei V. Volkov 《Journal of Cluster Science》1997,8(1):27-45
Thioselenohalide complexes Mo2(μ-S2)2Cl6(SeCl2)2 (I), Mo2(μ-S2)2Br6(SeBr2)2 (II), and W2(μ-S2)2Br6(SeBr2)2 (III) were synthesized by the reactions of corresponding metal halides or carbonyls or molybdenum metal with excesses of S2 X 2+Se2 X 2 mixtures. The complex W2(μ-S2)2Cl6(SeCl2)2 (IV) was obtained by an exchange reaction between (III) and excess of Se2Cl2. Coordination of the neutral SeX 2 ligands to thiohalidesM 2(μ-S2)2 X 6 results in higher thermal stability, and suggests the possibility to synthesize SeX 2 complexes of the unstable parent tungsten thiohalides. An unusual oxidative addition reaction of (I) was detected: {fx27-1} Both (I) and (IV) were characterized by X-ray crystal structure analysis. They are isostructural and form discrete molecules. Bridging S 2 2? ligands are coordinated perpendicularly to the metal-metal bond;d(M?M)=2.8066 Å and 2.793 Å for I and IV, respectively. Nonequivalence of chlorine atoms which are bound to the metal atom, relate to nonequivalence of halogen atoms in the complexesM 2(μ?S2)2 X 8 2? . Chlorine atomstrans to SeCl2 ligands form short bonds with the metal; the corresponding35Cl NQR frequency is increased. The selenium dichloride ligand is ambidentate. The selenium atom binds as a donor to the metal and as an acceptor to two chlorine atoms which are also bound covalently to the same metal atom. 相似文献
24.
An expression for electron transfer rate has been obtained through the solution of a time wave equation by the variational method by defining the wave function as a linear combination of functions corresponding to electron localization on the donor and on the acceptor. A dependence of electron transfer on temperature, on the electronic and vibrational characteristics of the system has been derived. An activation energy temperature-variation effect has been obtained. It has been proved that many-electron transfers are impossible. 相似文献
25.
L. A. Petrov N. P. Lobanova V. L. Volkov G. S. Zakharova I. P. Kolenko L. Yu. Buldakova 《Russian Chemical Bulletin》1989,38(9):1806-1809
Polyvanadomolybdic acids catalyze the process of peracid oxidation of 1,2,4-trimethylbenzene. The selectivity with respect to 2,3,5-trimethyl-1,4-benzoquinone increases with increasing degree of replacement of vanadium atoms in the PVMA by molybdenum; this is related to increased stability of the intermediate peroxides of the heteropolyvanadates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1967–1969, September, 1989. 相似文献
26.
The title compound has been studied by an X-ray structure analysis (a CAD-4 diffractometer, MoK, graphite monochromator, /2 scan, 2
max, direct methods, 884 reflections R=0.0416). The crystals are orthorhombic with a=20.326, b=8.828, c=7.3872 Å, V=1325.6 Å3, and Z=4. C8H18B9N, space group Pnam, dcalc=1.130 g/cm3, dexp=1.130 g/cm3. The compound is a molecular complex. The main feature of its crystal structure is the coexistence of two asymmetric mirror isomers which have the same pyridine cycle and the same atoms of the carborane skeleton (excluding C7, H7C, and H34). The methyl group has a disordered orientation in two positions. The complexes are linked by van der Waals interactions.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 4, pp. 149–153, July–August, 1993.Translated by T. Yudanova 相似文献
27.
K. A. Volkova A. N. Nikol'skaya E. P. Levanova A. N. Volkov B. A. Trofimov 《Chemistry of Heterocyclic Compounds》1979,15(12):1296-1298
Alkylthio-substituted dienic 1,3-dioxolan-2-ones and bis(4,4-diorganyl-5-methyli-dene-1,3-dioxolan-2-ones) were obtained in high yields by the reaction of 2-methyl-6-alkylthio-5-hexen-3-yn-2-ols and tertiary diacetylenic glycols with carbon dioxide under pressure in the presence of catalytic amounts of triethylamine and monovalent copper salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1617–1619, December, 1979.Original article submitted January 24, 1979. 相似文献
28.
Kotov V. V. D'yakonova O. V. Sokolova S. A. Volkov V. I. 《Russian Journal of Electrochemistry》2002,38(8):888-891
The transport of water molecules and the distribution of functional groups in polyamidoacid carboxyl-containing cation-exchange membranes based on pyromellitic acid are studied by NMR and ESR techniques. It is shown that the self-diffusion coefficients of water differ in the gel and intergel regions. Structural parameters of conducting channels in the gel regions are determined. In electrodialysis of one-component and binary solutions, polyamidoacid membranes possess higher transport numbers and separation coefficients of counterions that are less hydrated in solution. 相似文献
29.
Crystal structure of di (1-n-dodecylpyridine) decahydro-closo-decaborate(2-) (C5H5N-C12H25)2[B10H10]
A. V. Virovets N. N. Vakulenko V. V. Volkov N. V. Podberezskaya 《Journal of Structural Chemistry》1994,35(3):339-344
Using X-ray analysis, we have determined the crystal structure of di(1-n-dodecylpyridine) decahydrocloso-decaborate(2-), (py-C12H25)2[B10H10] (I), a yellow salt-like substance obtained by reaction of (py-C12H25)Br and K2[B10H10] in an aqueous solution. Compound I melts at 1250 without decomposition and luminesces under ultraviolet radiation (λmax=555 nm at 298 K). In I, quaternary pyridine bases, containing a hydrocarbon radical with the C12 chain, are combined with the closo-cluster hydroborate anion [B10H10]2-. This results in a charge transfer structure having shortened nonvalent (equatorial B) H.…H(C of pyridine) contacts of 2.41(8) Å. Crystals I are orthorhombic with a=8.584 (1), b=7.739(1), c=31.183(5) Å, Vcell=2071.4(5) Å3, space group Pnmm, Z=2, dcalc=0.986 g/cm3 (a Syntex P21 automatic diffractometer, λCUKα, Nmsd/used=1654/711, Raniso=0.076, Rw=0.080, w=1/(σ(Fobs)2+0.0007·F obs 2 ). Substantial changes are observed in the vibration range of the valent B?H bonds in the IR spectrum of I as compared to that of pure ionic K2[B10H10], confirming the interaction. 相似文献
30.
Formation of large-scale hydrodynamic convective patterns in plasma-like current-carrying media is considered. This process is shown to be described by the same equations, as Benard rolls, except that a temperature field must be replaced by a magnetic field. A simple low-mode model of spatial pattern formation for a case of cylindrical liquid-metal conductor with current is proposed and investigated. Nonlinear interaction of perturbations of the magnetic field and the velocity field results in an increase of effective conductor resistance even when transport coefficients are constant. In our opinion, it is this instability, that is of first importance at the initial stages of the electric explosion of conductors. In particular, it leads to conductor stratification and electric current interruption. (c) 1996 American Institute of Physics. 相似文献