Bibliometric Analysis of the <Emphasis Type="Italic">Journal of Structural Chemistry</Emphasis>

Bibliometric analysis has been carried out for the Journal of Structural Chemistry (JSC) published since 1960 by the Siberian Branch of the Russian Academy of Sciences. All JSC publications which appeared between 1960 and 2002 have been chosen online from the Chemical Abstracts and Science Citation Index databases of the STN International net and analyzed according to topics, authors, affiliations, and other criteria. JSC authors and publications with the largest numbers of citations have been identified. The impact factor has been determined for JSC 2002.Original Russian Text Copyright © 2004 by V. M. Buznik, I. V. Zibareva, V. N. Piottukh-Peletskii, and N. I. Sorokin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1142–1153, November–December, 2004.     

Phase equilibria and thermodynamics of coexisting phases in rare-earth element-iron-oxygen systems. II. The praseodymium-iron-oxygen system

The phase equilibria and the thermodynamics of coexisting phases in the PrFeO system have been studied using static and dynamic methods for attaining equilibrium with subsequent annealing and identification of the condensed phases by X-ray analysis. Equilibrium phase diagrams have been constructed to define the changes that take place in the PrFeO system on variation of the partial oxygen pressure, the temperature, and the composition of the initial mixture of oxides. An isothermal cross section at 1300°K and equilibrium diagrams of the type P_O2 = f(composition) with with one composition parameter fixed and T = f(composition) with P_O2 = constant have been constructed. It has been shown in the PrFeO system that only one ternary compound with perovskite structure, PrFeO₃, is formed, and furthermore, it is stable no matter how high the partial oxygen pressure.     

Synthesis of N(1)-substituted 5-amino-3-methylpyrazoles

With the aim of preparing new biologically active compounds a series of N₍₁₎-substituted 5-amino-3-methylpyrazoles has been obtained from -aminocrotononitrile and mono-substituted hydrazines.K. A. Timiryazev Moscow Agricultural Academy, Moscow 127550, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, 342–344, March, 2000.     

Copper (II) complexes of sterically hindered o-diphenol derivatives: synthesis, characterization and microbiological studies

Cu (II) complexes with the sterically hindered diphenol derivatives 3,5-di(tert-butyl)-1,2-benzenediol (I), 4,6-di(tert-butyl)-1,2,3-benzenetriol (II) and the sulfur-containing 4,6-di(tert-butyl)-3-(2-hydroxyethylsulfanyl)-1,2-benzenediol (III) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (IV) have been synthesized and characterized by elemental analysis, TG/DTA, FT-IR, ESR, XPS, XPD and conductivity measurements. Compounds I–III can coordinate in their singly deprotonated forms and act as bidentate ligands. These compounds yield Cu (II) complexes of the stoichiometry Cu(L)₂, which have square planar geometry (g_| > g_⊥ > g_e). Unlike them, compound IV behaves as a terdentate ligand, and its complex Cu(L^IV)₂ has distorted octahedral geometry. According to ESR data, only the Cu(L^II)₂ complex contains a very small amount of phenoxyl radicals. Antimicrobial activities of these ligands and their respective Cu (II) complexes have been determined with respect to Gram-positive and Gram-negative bacteria, as well as on yeasts. Their phytotoxic properties against Chlorella vulgaris 157 were also examined.     

Anionic high-temperature conduction in single crystals of nonstoichiometric phases R1 ? y M y F3 ? y (R = La-Lu, M = Ca, Sr, Ba) with the tysonite (LaF3) structure

Electrophysical properties of single crystals of nonstoichiometric phases R_{1 − y} M _y F_{3 − y} , where R = La-Lu, M = Ca, Sr, or Ba, with the tysonite (LaF₃) structure, which are present in a metastable state after being grown and cooled, are measured in the temperature interval extending from 300 to 1073 K. It is discovered that, during a sufficiently long high-temperature investigation, solid solutions R_{1 − y} Ca _y F_{3 − y} , where R = Tb, Dy, or Ho, undergo irreversible variations in the phase composition in the temperature region 723 to 823 K. This level of temperatures, which correspond to partial decomposition of phases R_{1 − y} Ca _y F_{3 − y} with the rare-earth elements of the end of the period, lies above the temperatures to which the fluoride solid electrolytes are usually heated when used in solid-state electrochemical devices. The temperature and concentration dependences of the phases’ electroconduction are explained in the framework of the vacancy mechanism of anionic transport. Original Russian Text ? N.I. Sorokin, B.P. Sobolev, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 4, pp. 420–431. The paper is dedicated to the memory of Prof. M.W. Breiter, formerly of the Vienna Technical University, Austria.     

Characteristics of the cholinesterase of the venom of the central Asian cobra

Summary 1. By rechromatography on sulfoethyl-Sephadex C-50, an electrophoretically homogeneous preparation of cholinesterase has been obtained from the venom ofNaja oxiana Eichwald.2. The activity of the cholinesterase isolated depends on the concentration of the enzyme and the time and temperature of incubation, and also on the pH. The following must be considered the optimum conditions: time of incubation of the enzyme with the substrate 20–30 min, pH 8.0–8.5, temperature 37–38°C.3. Diisopropyl phosphorofluoridate (DIPF) in a concentration of 2 µM completely suppresses the activity of the cobra venom cholinesterase.4. The venom cholinesterase hydrolyzes acetylcholine chloride and acetylthiocholine bromide but has no effect on butyrylthiocholine bromide, in which respect it resembles the true cholinesterases.5. Preparations of cobra venom cholinesterase do not possess a lethal action and do not potentiate the activity of the neurotoxins of the same venom.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 783–789, November–December, 1972.     

Negative ion mass spectra and structure of 4-substituted 1-phenyl-3-methyl-5-pyrazolones

This is the first study of the electron capture dissociative resonance (ECDR) mass spectra of 4-substituted 1-phenyl-3-methyl-5=pyrazolones. The major features of the fragmentation of these compounds under ECDR. conditions were found relative to their substituent properties. After loss of the methyl group from the nitrogen atom, the pyrazolone ring isomerizes to a pyrazole ring with localization of the negative charge on the oxygen atom of the carbonyl group. The intensity of the [M - Ch₃]^– fragment depends on the substituent properties.Communication 5 in the series on the Mass Spectroscopy of Biologically Active Compounds, For Communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1663–1670, December, 1985.     

Anion Transport in BaR2F8 Crystals at Elevated Temperatures

Electroconduction of BaR₂F₈ crystals (R = Y_0.9Er_0.1, Y_0.5Yb_0.5, Er_0.945Tm_0.05Ho_0.005) with the structure -BaTm₂F₈ (monoclinic syngony, spatial group C2/m) is studied at 323–1073 K. Effect of partial pyrohydrolysis on the conduction of Ba(Y, Er)₂F₈ single crystals is investigated. Anion conductivity of crystals of Ba(Y, Yb)₂F₈ and Ba(Er, Tm, Ho)₂F₈ is measured at high temperatures. To a first approximation, there is no change in the ion transport mechanism in these crystals at elevated temperatures. Charge carriers in BaR₂F₈ crystals are, most probably, fluorine vacancies, and the anion conductivity reaches 1–2 mS cm^–1 at 1073 K.     

Observation of difluorinated higher fullerene anions by Knudsen cell mass spectrometry and determination of electron affinities of C60F2 and C70F2

Difluorinated higher fullerenes have been studied by Knudsen cell mass spectrometry. Thermal negative ions C_nF₂⁻ (n=60, 70, 72, 74, 76 and 78) were produced inside the effusion cell as well as the neutral molecules C₆₀F₂ and C₇₀F₂. From the equilibrium constants for the electron exchange reactions between difluorinated fullerenes and their parents electron affinity values were derived for C₆₀F₂ (2.74 eV) and C₇₀F₂ (2.80 eV).