Structure of the dimethylsulfoxide molecule in neutral,acid, and alkaline media

The quantum-chemical SCF LCAO-MO calculations have been carried out in the MNDO/H approximation for the dimethylsulfoxide (DMSO) molecule, its anion [CH ₃ CH ₂ SO]^–, and DMSO adducts with HCL, OH^–, and H₂O. Bond lengths, interbond angles, effective charges on atoms, bond orders, ionization potentials, formation enthalpies, and dipole moments have been calculated. The comparative analysis of quantum-chemical and structural data of the compounds has been carried out.Baikov Institute of Metallurgy, Russian Academy of Sciences. Moscow Mendeleev Chemical Engineering Institute. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 3, pp. 31–35, May–June 1993.Translated by L. Smolina     

Thermodynamic properties of aqueous-organic systems with low water contents. 2. Limiting partial molar volumes of D2O and H2O intert-butyl alcohol and 1,4-dioxane at 288.15–318.15 K

The densities of dilute solutions of H₂O and D₂O in 1,4-dioxane and tert-BuOD have been measured in the interval 288.15–318.15 K with an error of 2·10^–6 g/cm³. The limiting partial molar volumes of D₂O and H₂O in 1,4-dioxane andtert-butanol have been determined by using an original procedure; the changes in the partial molar volume of water due to H-D substitution in the water molecules have been calculated. The analysis of the temperature dependence of the partial volumes of the components of the binary mixtures H₂O (D₂O) + 1,4-dioxane and H₂O (D₂O) +tert-BuOH (tert-BuOD) showed on the basis of Maxwell's crossing equations that the addition of small amounts of water significantly alters the structure of the unary organic solvent. In the presence of trace amounts of water the expansibility of 1,4-dioxane increases and that oftert-butanol decreases.For previous communication, see [1].Institute of the Chemistry of Nonaqueous Solutions, Russian Academy of Sciences, Ivanovo 153018. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 568–571, March, 1992.     

Crystalline and molecular structure ofDL-2-amino-4-phosphonobutyric acid monohydrate

The crystalline and molecular structure ofDL-2-amino-4-phosphonobutyric acid monohydrate has been studied by means of x-ray diffraction analysis. The acid molecule exists in a zwitterionic form with a deprotonated PO₃H₂ group. In the crystalline structure there is a branched system of intermolecular hydrogen bonding and the unusual intermolecular bond C–H...O=C forming part of it has been found.Institute of Physiologically Active Compounds, Russian Academy of Sciences, 142432 Chernogolovka. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2561–2565, November, 1992.     

Synthesis and molecular structure of 1,4-dimethyl-4,5,7,8-tetrahydro-6H-imidazo[4,5-e][1,4]-diazepine-5,8-dithione

1,4-dimethyl-4,5,7,8-tetrahydro-6H-imidazo[4,5-e][1,4]-diazepine-5,8-dithione was synthesized by boiling 1,4-dimethyl-4,5,7,8-tetrahydro-6H-imidazo[4,5-e][1,4]-diazepine-5,8-dione (a cyclic homolog of theobromine) with P₂S₅. Its molecular and crystal structures were determined by X-ray structure analysis, PMR spectroscopy and the calculations using the MM2 program. The crystals are monoclinic, sp. gr. P2 ₁ /n with a=9.305(4), b=9.464(3), c=11.628(3) Å, -90.49(3)^o, Z=4 for C₈H₁₀N₄S₂. M.p. 268–269 °C. The 7-membered heterocycle has a boat conformation in the crystal, while in solution at room temperature it undergoes interconversion. The geometrical parameters of the molecule obtained by X-ray structure analysis, by PMR spectroscopy below the coalescence temperature (290 K), and by MM2 calculations are in good agreement.A. V. Bogatsky Physico-Chemical Institute, Ukrainian Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 34, No. 3, pp. 86–90, May–June 1993.Translated by T. Yudanova.     

Electron diffraction study of the molecular structure of WO2F2

The saturated vapor over solid W ₂ O ₄ F has been studied by electron diffractometry. Structure analysis was fulfilled assuming complex composition of the vapor. It has been established that at T=1043±30 K the vapor consists of WO ₂ F ₂ and WOF ₄ molecules in amounts of 90 and 10 more % respectively. There are two alternative models describing the geometrical structure of the WO ₂ F ₂ molecule (C _2v symmetry) which fit experimental data equally well. In one model, the valence OWO angle is greater than the FWF angle, while in the other, the inverse relation is observed.Ivanovo State University. Moscow Mendeleev Chemical Engineering Institute. Ivanovo Chemical Engineering Institute. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 3, pp. 41–46, May–June 1993.Translated by L. Smolina     

Benzyl cleavage in the oxidation of cycleanine by mercuric acetate

The dehydrogenation of cycleanine with mercuric acetate in 10% AcOH (at the boil) has been studied. It has been shown that it is accompanied by oxidative cleavage similar to benzyl cleavage under the action of electron impact. The main reaction product (without complexone) is the 8-(4-hydroxymethylphenoxy)-6,7-dimethoxy-2-methylisoquinolinium salt C₁₉H₂₀NO₄Cl·1.5H₂O, mp 196°C. The oxidation of cycleanine in the presence of ethylenediaminetetraacetic acid gave the mercuride C₁₉H₁₉NO₃I₂Hg·2H₂O, mp 240°C (water).All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 676–680, September–October, 1979.     

Water-vapor pressure and thermodynamics of the dehydration of manganese,nickel, cadmium,and lead perchlorate hydrates

The water-vapor pressure has been measured by a static method, the temperature limits for existence have been determined, and the parameters of the equation lgp [Torr]=b —a/T have been calculated for the following crystal hydrates: Mn(ClO₄)₂ · 2H₂O (90–130°C, a=3527.0,b=8.487), Ni(ClO₄)₂ · 4H₂O (60–100°C,a=3606.7,b=9.704), Ni(C1O₄)₂ · 2H₂O (110–160°C,a = 4261.7,b = 10.103), Cd(ClO₄)₂ · 6H₂O (25–58.2°C,a = 3143.7,b = 9.356), Cd(ClO₄)₂ · 2H₂O (90–144.8°C,a=3823.3,b = 9.472), Pb(ClO₄)₂ · 3H₂O (10–47°C,a = 2932.9,b = 9.391 and 47–81.5°C,a = 2448.1,b=7.877), Pb(ClO₄)₂ · H₂O (60–102.4°C,a=3610.2,b = 9.857). A hitherto unknown metastable hydrate Cd(ClO₄)₂ · 4H₂O with a phase transition at 30.9°C (20–30.9°C,a = 3669.5,b = 11.343 and 30.9–63.7°C,a=3058.6,b = 9.339) has been detected.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 466–470, March, 1993.     

Sesquiterpene lactones from Artemisia caucasica

Conclusions 1. Two sesquiterpene lactones have been isolated from the epigeal green part ofArtemisia caucasica Willd.: one with the composition C₁₅H₁₈O₅·H₂O, which has been called grossmisin, and one with the composition C₁₅H₁₈O₅, identified as rutifolin. Structure (I) has been proposed for grossmisin.2. The structure of anhydroaustricin has been reviewed. Structure (II) is proposed for it.Pyatigorsk Pharmaceutical Institute. All-Union Scientific-Research Institute for Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 741–744, November–December, 1971.     

Dzheiranbatanolide — A new guaianolide fromArtemisia fragrans

A new guaianolide which has been called dzheiranbatanolide (I), C₁₅H₂₀O₄, mp 186–188°C has been isolated from the epigeal part ofArtemisia fragrans Willd. The oxidation of (I) led to a keto derivative (II) with the composition C₁₅H₁₈O₄, mp 247–248°C. The structure of (I) has been established by the chemical and spectral (IR, UV, and¹³C NMR) analysis of (I) and (II).V. L. Komarov Institute of Botany, Academy of Sciences of the Azerbaijan SSR, Baku. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 595–598, September–October, 1984.     

Crystal structures of bis(quinidinium) molybdate hydrate and quinidinium chloride hydrate: The question of the stable conformation of quinidine

Anx-ray structural study of [QndH⁺]₂[MoO ₄ ^2– ]H₂O (1) and [QndH⁺]Cl^–H₂O (2), where Qnd = quinidine, was conducted. The structures have an ionic structure, and the ions are joined by hydrogen bonds into chains (1) and layers (2). Quinidinium cations protonated at the quinuclidine N atom have a conformation with agauche position of the N atom and OH group (as in neutral quinidine) corresponding to the local, and not the global, minimum of the calculated conformational energy.A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1073–1078, May, 1992.     

Components ofHaplophyllum obtusifolium

Skimmianine, folimine, benzamide, and new alkaloid haplotusine (mp 118–119°C, C₁₁H₁₁NO₃, M⁺ 205) have been isolated from the epigeal part ofHaplophyllum obtusifolium Ledeb. growing in the environs of Kora-Koly, Turkmen SSR. By the analysis of spectral characteristics it has been established that haplotusine has the structure of 1,4-dimethoxy-2-quinolone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 635–636, September–October, 1984.     

Structure of ferulide

The structure of a new sesquiterpene lactone — ferulide fromFerula penninervis Regel et Schmalh — has been established on the basis of its spectral characteristics. This compound has the composition C₂₀H₂₄O₅, mp 135–137°C.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 240–242, March–April, 1987.     

Anionic radical and protonated form of molecular ozone. A nonempirical calculation taking into account the electronic correlation

The different electronic states of ozone (¹A₁,³B₂,³A₂,³B₁, and 2¹A₁) were calculated by a nonempirical method in the basis 4–31 G (d, p) taking into account the electronic correlation according to the Meller-Plesset theory of a fourth order perturbation theory (MP4). The geometric structures of the ions O ₃ ^– and O₃H⁺ were calculated. The evaluation of the affinity to the proton for O₃ gave a value (P_A=6.8 eV) 1 eV lower than that for H₂O.Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Rubezhansk Branch, Dnepropetrovsk Institute of Chemical Technology. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 28–32, March–April, 1993.     

Conversion of methane/carbon dioxide mixtures on vermiculite

A study has been made of the conversion of methane/carbon dioxide mixtures on a vermiculite catalyst of composition 22MgO·22SiO₂·5Al₂O₃·Fe₂O₃·4OH₂O. It has been established that at 900–970°C with molar ratios of CO₂/CH₄ of 0.5–1.5 and contact times of 10.5–21 sec the conversion proceeds quantitatively but the main products, H₂ and CO, are formed in varying proportions. An explanation has been given for the effect of the process parameters on the conversion and selectivity.Chernogolovka Institute of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1511–1515, July, 1992.     

A New Predictive Equation for the Surface Tensions of Aqueous Mixed Ionic Solutions Conforming to the Linear Isopiestic Relation

The linear isopiestic relation has been used, together with the fundamental Butler equations, to establish a new simple predictive equation for the surface tensions of the mixed ionic solutions. This newly proposed equation can provide the surface tensions of multicomponent solutions using only the data of the corresponding binary subsystems of equal water activity. No binary interaction parameters are required. The predictive capability of the equation has been tested by comparing with the experimental data of the surface tensions for the systems HCl–LiCl–H₂O, HCl–NaClO₄–H₂O, HCl–CaCl₂–H₂O, HCl–SrCl₂–H₂O, HCl–BaCl₂–H₂O, LiCl–NaCl–H₂O, LiCl–KCl–H₂O, NaCl–KCl–H₂O, KNO₃–NH₄NO₃–H₂O, and LiCl–NaCl–KCl–H₂O at 298.15 K; KNO₃–NH₄Cl–H₂O, KBr–Sr(NO₃)₂–H₂O, NaNO₃–Sr(NO₃)₂–H₂O, NaNO₃ –(NH₄)₂SO₄–H₂O, KNO₃–Sr(NO₃)₂– H₂O, NH₄Cl–Sr(NO₃)₂–H₂O, NH₄Cl– (NH₄)₂SO₄–H₂O, KBr–KCl–H₂O, KBr–KCl–NH₄Cl–H₂O, KBr–KNO₃– Sr(NO₃)₂–H₂O, KBr–NH₄Cl–Sr(NO₃)₂–H₂O, KNO₃–NH₄Cl–Sr(NO₃)₂–H₂O, and NH₄Cl–(NH₄)₂SO₄–NaNO₃–H₂O at 291.15 K; and KBr–NaBr–H₂O at temperatures from 283.15 to 308.15 K. The agreement is generally quite good.     

The structure and stereochemistry of tavicone

Summary It has been established from H¹ NMR spectra in CDCl₃ with additions of Eu(FOD)₃ as paramagnetic shift reagent that tavicone must be ascribed the structure of 7-(1,1,3a,5-tetramethyl-2-oxo- ₅ ⁵ -hexahydroinden-4-ylmethoxy) coumarin. The stereochemistry of this compound has been determined.Institute of Botany, Academy of Sciences of the Azerbaidzhan SSR, Baku. All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 452–455, July–August, 1976.     

Composition and structure of zirconium complexes in tributyl phosphate extracts of Zr from concentrated nitric acid solutions

Using quantitative difference IR spectroscopy we have found that the tibutyl phosphate & acts of zirconium from 12–15 M HN03 contain ionic associates [(TBP)₂H⁺]Zr(NO₃)₅ ^– (I) and [TBP· H₃0⁺ (H₂0)_n]Zr(N0₃)₅ ^– (II), where n = 1, 2, as well as the Zr(N0₃)₄(TBP)₂ complex at a lower concentration than (I) and (I.). The equilibrium I II is shifted toward II at higher C_{HNo 3} ⁰ and lower c_Zr ⁰. The structure of associates I and II is discussed.Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, D. I. Mendeleev Moscow Chemical Technological Institute. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 5, pp. 80–89, September–October, 1993.Translated by L. Smolina