Catalpa oil seeds. II

Summary 1. The new sesquiterpene lactone tanachin (I) has been isolated from a chloroform extract ofTanacetum pseudoachillea C. Winkl.2. With the aid of double and triple resonances, the chemical shifts and coupling constants of the protons of (I) have been determined. On the basis of these results and by the application of a paramagnetic shift reagent —Eu (FOD)₃ — the structure of 1,6-dihydroxygermacr-4,10(14),11(13)-trien-8,12-olide has been established for tanachin. The orientations of the hydroxy groups have been determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 462–467, July–August, 1976.     

Dimerization and Coordination Properties of Zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine in Relation to DABCO in <Emphasis Type="Italic">o</Emphasis>-Xylene and Chloroform

For the first time the interactions between zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine (Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc) and 1,4-diazabicyclo[2.2.2]octane (DABCO) in o-xylene and chloroform have been studied by calorimetric titration and NMR and electron absorption spectroscopic methods. It has been found that in o-xylene at concentrations of Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc higher than 6×10⁻⁴ mol⋅L⁻¹ π–π dimers species are formed (λ _max= 685 nm). Additions of DABCO to the solution up to mole ratio 1 : 8 (Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc : DABCO) lead to a shift of the aggregation equilibrium towards monomer species due to formation of monoligand axial complexes. Further increasing the DABCO concentration results in formation of Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc—DABCO—Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc sandwich dimers (λ _max= 675 nm).     

Composition and structure refinement of superconducting crystals Y1? x Tb x Ba2Cu3O6+δ ( x = 0.10; δ = 0.75)

Crystals of Y_0.90Tb_0.10Ba₂Cu₃O_6.75 have been prepared by spontaneous crystallization from slowly cooled non-stoichiometric melt of the system Y-Tb-Ba-Cu-O. Average size of platelet crystals having mirror surface is 2×2, the largest — 8×9 mm with thickness 0.1–0.2 mm. The crystals have been characterized by powder X-ray diffraction and electron microprobe analysis. Tetragonal symmetry of the crystals has been determined by X-ray diffraction. Magnetic susceptibility measurements have revealed that the crystals manifest transition to superconducting state without additional annealing (T _c = 60 K). Structures and compositions — Y/Tb ratio (σ = 0.01) and oxygen content (σ = 0.04) — have been refined for two single crystals. Possibility of rhombic distortion of the tetragonal symmetry is discussed. __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 6, pp. 1101–1107, November–December, 2008. Original Russian Text Copyright ? 2008 by L. P. Kozeeva, N. V. Podberezskaya, N. V. Kuratieva, M. Yu. Kamaneva, and A. G. Blinov     

Ruthenium-mediated Selective Aromatic Thiolation in the Complex [RuII{o-S—C6H4-(p-R-)—N=N—C3H2NN(1)—R′}2]. Synthesis, Spectroscopic, e.p.r., Electro-chemical Characterization and Spectro-electrochemical Correlation

The reaction of ctc-[Ru(RaaiR′)₂Cl₂] (3a–3i) [RaaiR′=1-alkyl-2-(arylazo)imidazole, p-R—C₆H₄—N=N— C₃H₂NN(1)—R′, R=H, OMe, NO₂, R′=Me, Et, Bz] with KS₂COR′′ (R′′=Me, Et, Pr, Bu or CH₂Ph) in boiling dimethylformamide afforded [Ru^II{o-S—C₆H₄(p-R-)—N=N—C₃H₂NN(1)—R′}₂] (4a–4i), where the ortho-carbon atom of the pendant phenyl ring of both ligands has been selectively and directedly thiolated. The newly formed tridentate thiolate ligands are bound in a meridional fashion. The solution electronic spectra exhibit a strong MLCT band near 700 nm and near 550 nm, respectively in DCM. The molecular geometry of the complexes in solution has been determined by H n.m.r. spectroscopy. Cyclic voltammograms show a Ru(II)/Ru(III) couple near 0.4 V and an irreversible oxidation response near 1.0 V due to oxidation of the coordinated thiol group, along with two successive reversible ligand reductions in the range −0.80–0.87 V (one electron), −1.38–1.42 V (one electron). Coulometric oxidation of the complexes at 0.6 V versus SCE in CH₂Cl₂ produced an unstable Ru(III) congener. When R=Me the presence of trivalent ruthenium was proved by a rhombic e.p.r. spectrum having g₁=2.349, g₂=2.310.     

Raman scattering spectra and molecular conformations of bis(quaternaryammonium bromide)-water systems

The dimeric bis(quaternaryammonium bromide) surfactants, [Br⁻(CH₃)₂N⁺(C _m H_{2 m +1})—(CH₂) _s —(C _m H_{2 m +1})N⁺(CH₃)₂Br⁻, s = 2, 3 and m = 4, 6, 10 and 12, s = 6 and m = 8, 10, 12], have been synthesized and the phase maps of the sm6-8-water, sm6-10-water and sm6-12-water binary systems have been determined (sm6-8 implies s = 6, m = 8). In order to examine the molecular structures of these solid samples and of their dimeric surfactant-water binary systems, Raman spectra of the simple dimeric surfactants, sm2-4 and sm3-4, in which crystal structures of the trans- and cis-type conformations have been determined by single-crystal X-ray diffraction analysis, have been investigated, and Raman bands characteristic of these skeletal structures were found in the skeletal deformation region. On the basis of these characteristic Raman bands for the two conformations, it has been concluded that the dimeric surfactants, sm6-8, sm6-10 and sm6-12 also take up a cis-type conformation in the crystalline state. Furthermore, it has been found that the Raman bands in the C—H stretching, skeletal stretching and CH₂ scissoring regions are sensitive to phase structure. Received: 21 July 1998 Accepted in revised form: 9 November 1998     

Crystal structure, spectroscopic and magnetic properties, and antimicrobial activities of cobalt(II) 2-methylthionicotinate complexes with N-heterocyclic ligands

Synthesis and characterization of 10 new 2-methylthionicotinate (2-MeSnic) Co(II) complexes, namely, [Co(2-MeSnic)₂L₂(H₂O)₂] · nH₂O (L is N,N-diethylnicotinamide—Et₂nia, ethylnicotinate—Etnic, nicotinamide—nia, isonicotinamide—isonia, N-methylnicotinamide—N-Menia, furo[3,2-c]pyridine—fpy, 2,3-dimethylfuro[3,2-c]pyridine—Me₂fpy or benzo[4,5]furo[3,2-c]pyridine—Bfp; n is 0, 1 or 2) as well as [Co(2-MeSnic)₂L₂] (L is ronicol—ron or 2-methylfuro[3,2-c]pyridine—Mefpy), are reported. The characterizations were based on physico-chemical and spectroscopic methods. The crystal structure of one of the complexes has been determined. In the molecular complex [Co(2-MeSnic)₂(Me₂fpy)₂(H₂O)₂], the Co(II) central atom, located at a symmetry centre, is octahedrally coordinated by an oxygen atom of the unidentate 2-MeSnic carboxyl group, the nitrogen atom of the pyridine ring of Me₂fpy, a water molecule and the corresponding centrosymmetrically located atoms. Also, biological activity of the complexes against various strains of bacteria and filamentous fungi has been investigated. It is concluded that by complexation of these nicotinate derivatives their biological activities are elevated. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Interactions of Some Amino Acids with Aqueous N,N-Dimethylacetamide Solutions at 298.15 and 308.15 K: A Volumetric Approach

The apparent molar volumes, V _φ , of glycine, L-alanine and L-serine were obtained in aqueous 0 to ∼4 mol⋅kg⁻¹ N,N-dimethylacetamide (DMA) solutions from density measurements at 298.15 and 308.15 K. The standard partial molar volume, V _φ ^o, and standard partial molar volumes of transfer, Δ_tr V _φ ^o, were determined for these amino acids. It has been shown that hydrophilic-hydrophilic interactions between charged groups of the amino acids and the —CON= group of DMA are predominant in the case of glycine and L-serine, but for L-alanine the interactions between its side group (—CH₃) and DMA are predominant. An increase in temperature increases the standard partial molar volumes but decreases the transfer volumes of the amino acids. The results have been interpreted in terms of cosphere overlap model.     

Pyridine based cerium(IV) phosphate hybrid fibrous ion exchanger

Both temperatures, T _C, (T _C —Curie temperature) and heat of the phase transition: ferroelectric-paraelectric, ΔH, in the Ba_xSr_1−xTiO₃ materials have been studied by means of the microcalorimetric method. The determined parameters were verified by either temperature dependence of the dielectric permittivity (Curie-Weiss law) or thermodynamic method. The effect of strontium content on T _C has been discussed. It was found that microcalorimetry is useful tool studying phase transition phenomena in ferroelectric perovskites.     

Triterpene glycosides of Thalictrum squarrosum. IV. Structures of squarrosides A1, A2, B1, and B2

Four new cycloartane glycosides have been isolated from a methanolic extract ofThalictrum squarrosum Stephan ex Willd.: squarroside A1 (I) — (21R, 22S, 23R)-3β-(β-D-glucopyranosyloxy)-21α-methoxy-21,23-epoxycycloart-24-ene-22β,30-diol, C₃₀H₆₀O₁₀; squarroside A2 (II) — the (21S)-epimer of compound (I); squarroside B1 (III) (21R, 22S, 23R)-3gb-[O-α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranosyloxy]-21α-methoxy-21,23-epoxycycloart-24-ene-22β,30-diol, C₄₃H₇₀O₁₄; and squarroside B2 (IV) — the (21S)-epimer of compound (III). The proposed structures were determined on the basis of¹H and¹³C NMR spectroscopy, FAB mass spectrometry, and chemical transformations. Irkutsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 516–523, July–August, 1989.     

Iodo Derivatives of Bimetallic Fe—Pd and Fe—Pt Complexes. Crystal Structures of

Summary.  Iodo derivatives of diphosphine-bridged heterobimetallic Fe—Pd and Fe—Pt complexeshave been prepared in which an alkoxysilyl ligand bridges the two metals in a μ₂−η²-SiO manner. In the course of their synthesis by halide exchange from (dppx = dppm (Ph₂ PCH₂ PPh₂) or dppa (Ph₂PNHPPh₂); M = Pd or Pt), loss of the alkoxysilyl ligand occurred resulting in the formation of complexes in which a bridging iodide has replaced, as a 3e⁻-donor, the bridging alkoxysilyl ligand. These complexes of formula (M = Pd, Pt are better prepared by reaction of with [MI₂(cod)]. The crystal structures of (2a), (2b), and  · CH₂Cl₂ (3b · CH₂Cl₂) have been determined by X-ray diffraction. Received January 24, 2001. Accepted February 12, 2001     

Correlation between X-ray crystallography and nuclear quadrupole resonance data: Antimony halides and chalcogenides

For 53 compounds containing 73 crystallographic types of SbX _n coordination polyhedra (X is a halogen and/or chalcogen), parameters of the Voronoi-Dirichlet (VD) polyhedra characterizing the asymmetry of the crystal field in the vicinity of Sb nuclei—the displacement of the Sb nucleus from the centroid of its VD polyhedron (D _A) and the noncentrosymmetry parameter of the atomic environment (A _ns)—have been determined. There is a linear correlation between the experimental ¹²¹Sb quadrupole coupling constants determined from nuclear quadrupole resonance spectra and the D _A and A _ns values calculated from crystal-chemical data.     

Electrochemical properties of the system of Ag—1-butyl-3-methylimidazolium bromide low-temperature ionic liquid—silver bromide

The methods of potentiometry, electrochemical impedance spectroscopy, cyclic voltammetry, and gravimetry were used to study the electrochemical behavior of a silver electrode in low-temperature ionic liquids of BMImBr and BMImBr—AgBr, and also the process of cathodic reduction of Ag(I) compounds out of a BMImBr—AgBr melt. It is shown that an AgBr film is formed on the silver surface and its properties are determined by the ionic liquid composition. It is found that the process of silver electrodeposition from a BMImBr—AgBr binary alloy occurs irreversibly, at a high current efficiency (up to 100%) and a good quality of the deposit at low current densities. At 70°C, the transfer coefficients of the cathodic process (α = 0.56 and 0.16) and diffusion coefficients (D _Ag(I) = 0.48 × 10⁻⁷ cm²/s and 3.3 × 10⁻⁷ cm²/s) of silver-containing ions are determined in ionic liquids with the AgBr concentration of 0.81 and 1.53 mol/kg BMImBr, accordingly.     

Alkaloids ofArundo donas VII. A spectroscopic and X-ray structural investigation of arundinine—A new dimeric alkaloid from the epigeal part ofArundo donax

FromArundo donax L. we have isolated the new dimeric alkaloid arundinine, with the composition C₂₃H₂₈N₄O, the structure of which has been established on the basis of its physicochemical characteristics and¹H and¹³C NMR spectroscopy, including 1D and 2D experiments in both homo- and heteronuclear regimes. The proposed structure—3a-(3′-dimethylaminoethylindol-5′-yloxy)-1-methylpyrrolidino[1a,3a-b]indoline — has been confirmed by x-ray structural analysis (XSA). Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 790–795, November–December, 1998.     

Synthesis and structure of novel chiral amido-imine complexes of aluminum,gallium, and indium

The reactions of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN, 1) with tri-iso-butylaluminum, triethylgallium or trimethylindium give the novel amido-imine complexes (Buⁱ—dpp-BIAN)AlBuⁱ ₂ (4), (Et—dpp-BIAN)GaEt₂ (5), and (Me—dpp-BIAN)InMe₂ (6), respectively. The reaction of (dpp-BIAN)AlI(Et₂O) (7) with allyl bromide affords analogous chiral amido-imine derivative (All—dpp-BIAN)AlBrI (8). Hydrolysis of 8 affords the amino-imino compound (All—dpp-BIAN)H (9). The new compounds 4–6, 8, and 9 have been characterized by ¹H NMR and IR spectroscopy. The molecular structures of 5, 6, and 9 were determined by single crystal X-ray analysis.     

Sorption von Jod an hydratisiertem Mangandioxyd

The distribution coefficients for iodine have been determined in the system “hydrated manganese dioxide—nitric acid” (K _D∼10⁴). Some factors affecting the kinetics and yield of sorption are discussed, and the possibilities of practical application indicated. A mechanism is outlined to explain the sorption of iodine on hydrated manganese dioxide.      

Intermolecular interactions in 2,4-dinitrophenylhydrazine hydrochloride hydrate: X-ray structural and quantum mechanical study

2,4-dinitrophenylhydrazine hydrochloride hydrate (I) was determined by X-ray crystallography, and the intermolecular interaction energies were calculated in terms of Natural Bond Orbital analysis. The asymmetric unit of (I) consists of a dinitrophenylhydrazinium cation, a chloride anion and a water molecule. The interatomic distances and angles in (I) show no unusual values. In the structure there are intermolecular N—H⊎⊎⊎O, N—H⊎⊎⊎Cl, O—H⊎⊎⊎Cl, C—H⊎⊎⊎O hydrogen bonds with bonding energy ranging form 16.03 to 0.76 kcal mol⁻¹. These hydrogen bonds create the following N1 motifs: 6D, S(5), S(6), C(6), C(9). N₁D motifs become infinite at the third level and are 2C₃²(6), C₃²(7).      

The kinetics of the oxidation of cyclopentanone with decaneperoxysulfonic acid

The kinetics of the oxidation of cyclopentanone with decaneperoxysulfonic acid at 291–323 K in CCl₄ has been studied. The reaction is not autocatalytic, and its rate increases linearly with increases in the concentrations of each of the reagents. The addition of CF₃COOH does not affect the reaction rate. The observed results are explained within a scheme which is a special case of the well-known Baeyer-Villiger reaction mechanism established for peroxycarboxylic acids. The effective rate constant of the process has been determined: logk (L mol⁻¹ s⁻¹)=(7.6±1.7) — (42.1±9.6)/θ, where θ=2.30RT kJ mol⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1827–1829, October, 1993.     

Three-parametric equation in evaluation of thermal dissociation of reference compound

Further considerations concerning thermal decomposition of reference material — CaCO₃, described by three-parametric equation in version (3), have been presented. It was established that in linear relationship between coefficients of Eq. (3) a ₂ is the argument of a ₁, which reaches minimal value of thermodynamic character (δH/vR) when a ₂=0 (equilibrium relationship). During thermal decomposition connection between system atmosphere — rich in CO₂ or vacuum, caused by fast evacuation of gaseous products — and activation energy value, as well as maximal temperature of reaction process. Conditions of this kind may be explained by Zawadzki-Bretsznajder law.     

Inclusion compounds of cucurbit[<Emphasis Type="Italic">n</Emphasis>]urils with metal complexes

A new class of supramolecular compounds—inclusion compounds of metal complexes encapsulated in organic macrocyclic cavitands cucurbit[n]urils (CB[n], C_6n H_6n N_4n O_2n , n = 7−10)—has been surveyed. A unique combination of a rather rigid hydrophobic intramolecular cavity and negatively charged portals favors the formation of stable host-guest compounds. Basic methods of synthesis of inclusion compounds of CB[n] with metal complexes have been reported, and the structures of the resulting products isolated as crystals and characterized by X-ray crystallography have been considered. The effect of encapsulation on the geometric and spectral characteristics of the complexes and their redox properties has been traced. It has been shown that encapsulation in CB[n] can lead to a change in the reactivity of the complexes in thermolysis and isomerization and aquation reactions. Encapsulation of biologically active metal complexes in CB[n] is a promising strategy for designing new-generation prolonged-action pharmaceuticals.     

New synthesis of moraprenyl bromide

An efficient method for the synthesis of moraprenyl bromide by the reaction of moraprenol (WT₃C_6—8—OH), the polyprenol from the mulberry tree Morus alba leaves, with bromo-trimethylsilane has been elaborated.