Synthesis of nonequilibrium Ir<Subscript>x</Subscript>Re<Subscript>1-x</Subscript> solid solutions. Crystal structure of [Ir(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl]<Subscript>2</Subscript>[ReCl<Subscript>6</Subscript>]Cl<Subscript>2</Subscript>

Synthesis of five binary complex salts with an [Ir(NH₃)₅Cl]²⁺ complex cation is described. The counterions are [ReCl₆]^2–, [IrCl₆]^2–, [ReBr₆]^2–, and Cl^–. A polycrystal X-ray diffraction study has been performed for [Ir(NH₃)₅Cl]₂[ReCl₆]Cl₂, and its crystal structure has been determined. A series of Ir _x Re_1–x phases (0.5 x > 1) were obtained by reductive thermolysis. For the Ir-Re system, the history of the V/Z(x) dependence has been refined.Original Russian Text Copyright © 2004 by S. A. Gromilov, S. V. Korenev, I. V. Korolkov, K. V. Yusenko, and I. A. BaidinaTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 508–515, May–June 2004.     

Berberis Alkaloids XXXVIII. Turcamine — A new isoquinoline alkaloid fromBerberis turcomanica

The new isoquinoline alkaloid turcamine (1) has been isolated from the leaves ofBerberis turcomanica, and its structure has been established as 8-hydroxy-7-methoxy-2-methyltetrahydroisoquinoline. A relationship has been found between a substituent at C-8 and the multiplicities of the signals from C-5 and C-6.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 894–896, November–December, 1996. Original article submitted April 15, 1996.     

Polarographic behaviour of 2-benzilidenimino-benzohydroxamic acid (2-BIBH) and 2-BIBH-Mo(VI) system

The polarographic behaviour of 2-benzilideniminobenzohydroxamic acid (2-BIBH) solutions and of 2-BIBH solutions in the presence of Mo(VI) have been studied by using differential pulse polarography and cyclic voltammetry. The polarographic characteristics of the resulting waves have been studied and possible mechanisms of the processes involved have been proposed. A linear relationship has been observed betweenI _p and Mo(VI) concentration in the range 2×10^–6 to 1.6×10^–5 M when using 3×10^–4 M 2-BIBH. Standard deviations of 5.6×10^–8 and 1.2×10^–8 M were found for 3×10^–6 and 8 × 10^–6 M Mo(VI), respectively.     

Determination of cerium in rare earth ores by fluorescence quenching of rhodamine 6G

A fluorescence quenching method has been developed to determine cerium with rhodamine 6G. The method is based on the oxidation of rhodamine 6G by cerium(IV) in sulfuric acid solution. The linear calibration range is 4.0 × 10^–7 -1.6 × 10^–6mol/L. The detection limit is 1.0 × 10^–7 mol/L. The relative standard deviation was 1.0% (n = 5). The method has been used to determine cerium in rare earth ores, with satisfactory results. The method offers the advantages of simplisity, sensitivity and selectivity.     

On the hyperfine structure in the configuration 5f 3 6d7s 2 of neutral uranium

A Laser Induced Fluorescence experiment in an atomic beam has yielded experimental values of hyperfine structure (hfs) constants A and B for 28 low odd levels and 22 even levels, with an accuracy around 10^–5 cm^–1 for A and 10^–3 cm^–1 for B. A Condon Slater Racah parametric interpretation of the hfs data concerning 22 of these levels, on the basis of the configuration 5f ³ 6d 7s ², has provided values of monoelectronic parametersa _5f ⁰¹ ,a _5f ¹² ,a _6d ⁰¹ ,b _5f ⁰² ,b _6d ⁰² ,b _6d ¹³ . A least square fit calculation has been compared to the values deduced from Dirac-Fock monoelectronic radial integrals. The fit represents 18 A (16 B) values ranging from –0.42 to –2.96 mK (from –41 to 156 mK) with discrepancies less than 0.2 mK (8 mK).     

Ab initio Calculation of the charge distribution and the ligand field splitting in the tetrahedral halo complexes CuCl 4 2− 4 and NiCl 4 2−

The charge distribution and the ligand field splitting in the tetrachloro complexes CuCl ₄ ^2– and NiCl ₄ ^2– have been investigated by means of the restricted Hartree-Fock method. A rather large basis set of contracted Gaussian type orbitals has been employed. The charge distributions have been analysed by means of Mulliken population analyses. The ligand field splitting 10Dq has been compared with literature results known for the octahedral cluster NiF ₆ ^4– occurring in KNiF₃. A detailed analysis has been carried out for CuCl ₄ ^2– . From calculations on a selected number of states of NiCl ₄ ^2– the Racah parameters B and C have been obtained.     

6-O-galloylarbutin fromRhodiola coccinea

Summary A phenolic glycoside for which the structure of 1-O-p-hydroxyphenyl-6-O-galloyl--D-glucopyranoside has been established has been isolated from the epigeal organs of theRhodiola coccinea (Royle) A. Bor.Arbutin and its 6-O-galloyl derivative are the dominating phenolic components of the plant.Tomsk Medical Institute. Khar'kov Scientific-Research Insitute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 474–478, July–August, 1975.     

Infrared and Raman Spectra,Conformational Stability,Ab Initio Calculations,and Vibrational Assignments for Cyclopropyldifluorosilane

The infrared (3200–30 cm^–1) spectra of gaseous and solid Cyclopropyldifluorosilane, c-C₃H₅SiF₂H, and the Raman spectra (3200–20 cm^–1) of the liquid with quantitative depolarization values and the solid have been recorded. Both the syn (cis) and skew (gauche) conformers have been identified in the fluid phases, but only the syn conformer remains in the solid. Variable temperature (–55 to –100°C) studies of the infrared spectra of the sample dissolved in liquid xenon have been carried out. From these data, the enthalpy difference has been determined to be 73 ± 10 cm^–1 (209 ± 29 cal mol^–1), with the syn conformer being the more stable rotamer, which is at variance with the predictions from ab initio calculations. A complete vibrational assignment is proposed for both conformers based on infared band contours, relative intensities, depolarization values, and group frequencies. The vibrational assignments are supported by normal coordinate calculations utilizing the force constants from ab initio MP2/6-31G* calculations. Utilizing the frequencies of the silicon–hydrogen sketch, the rm Si—H bond distances of 1.474 and 1.472 Å have been obtained for the syn and skew conformers, respectively. Complete equilibrium geometries have been determined for both rotamers by ab initio calculations employing the 6-31G* and 6-311 +G** basis sets at levels of restricted Hartree-Fock (RHF) and/or Moller–Plesset (MP) to second order. The potential energy terms for the conformer interconversion have been obtained from the MP2/6-31G* calculation. The results are discussed and compared to those obtained for some similar molecules.     

Isolation of fusicoccin from a culture filtrate ofFusicoccum amygdali

Fusicoccin A has been isolated from a culture filtrate of the filtrate of the fungusFusicoccum amygdali Del., and it has been characterized as an -glycoside of a tricyclic diterpenoid. The trimethylsilyl derivative of fusicoccin A has been investigated by combined GLC and mass spectrometry.All-Union Scientific-Research Institute of Applied Biology and Genetics, VASKhNIL, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 792–796, November–December, 1980.     

Lesterone, a new phytoecdysteroid from the seeds ofLeuzea carthamoides

A new phytoecdysteroid, lesterone has been isolated from the seeds ofLeuzea (Rhaponticum)carthamoides. It has been unambiguously identified as 5b-cholest-7-en-2a,3a,11b,14a,20R,22R,25-heptahydroxy-6-one with the aid of NMR and mass spectroscopies.Institute of Petrochemistry and Catalysis, Academy of Sciences of the Bashkortostan Republic, prospekt Oktyabrya 141, Ufa 450075, Russia. Published in Khimiya Prirodnykh Soedinenii, No. 2 pp. 205–206, March–April, 1999.     

Transformation of aromatic compounds under the action of the basidiomycetesPhanerochaete sanguinea andCoriolus villosus

The pathways of the transformation of some aromatic compounds by rhe basidiomycetesPhanerochaete sanguinea andCoriolus villosus have been studied. It has been shown that the degradation of these compounds has an oxidative nature and depends on the type of substituents in the benzene ring and the propane chain. A difference has been found in the mechanisms of the reactions of the two fungi that is a consequence of the different compositions of their enzyme complexes.Wood Chemistry Division, Institute of Organic Chemistry, Siberian Division of the Russian Academy of Sciences, Irkutsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 808–819, November–December, 1994.     

Spectra and Structures of Silicon-Containing Compounds. XXIV.* Raman and Infrared Spectra,r 0 Structural Parameters,Vibrational Assignment,Barriers to Internal Rotation,and Ab Initio Calculations of Ethylsilane

The infrared (3200 to 400 cm^–1) and Raman (3200 to 20 cm^–1) spectra of gaseous and solid ethylsilane, CH₃CH₂SiH₃, have been recorded. Additionally, the Raman spectrum of the liquid has been obtained with quantitative depolarization values. The SiH₃ torsional mode has been observed as sum and difference bands with the silicon-hydrogen stretching vibration. Utilizing the torsional fundamental frequency of 132 cm^–1 the threefold periodic barrier of 590 cm^–1 (7.06 kJ/mol) has been obtained. Utilizing the frequencies of the silicon-hydrogen stretches, Si-H bond distances of 1.485 and 1.484 Å have been obtained for the bonds gauche and trans to the methyl group, respectively. Using previously reported rotational constants from seven different isotopomers, the r ₀ parameters have been calculated and are compared to the corresponding r _s parameters. A complete vibrational assignment is proposed that is consistent with the predicted frequencies utilizing the force constants from ab initio MP2/6-31G(d) calculations. Both the infrared intensities as well as the Raman activities and depolarization values have been obtained from the ab initio calculations. Complete equilibrium geometries have been determined by ab initio calculations employing the 6-31G(d), 6-311 + G(d,p), and 6-311+G(2d,2p) basis sets at levels of restricted Hartree–Fock (RHF) and/or Moller–Plesset (MP) to second order. The results are discussed and the theoretical values are compared to the experimental values when appropriate.     

Extending the dynamic range of the determination of copper by adsorption differential pulse stripping method using a principal component artificial neural network

A principal component artificial neural network (PC-ANN) has been applied for the analysis of the voltammogram data of Cu(II) and Cu(II)–PAN complex for extending the dynamic range of the determination of Cu(II) (5–550 μg/l). A three layer back-propagation network (6:5:1) was used with learning rate (r=0.09) and momentum (m=0.9), with sigmoidal transfer function in the hidden layer and one bias node in the input layer. Overall, the application of PC-ANN enables the extension of the dynamic range of the determination of Cu(II) from its narrow linear range (5–50 μg/l) to the high dynamic range (5–550 μg/l).     

Composition of the lipids and carbohydrates of the seeds ofAmaranthus caudatus

The chemical composition of the seed lipids ofAmaranthus caudatus L. has been investigated. The fatty acid compositions of the neutral lipids and of the phospho- and glycolipids have been determined. The hydrocarbon components ofA. caudatus have been identified and its alcohol-soluble carbohydrates, water-soluble polysaccharides, and pectin substances have been characterized.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 797–799, November–December, 1997.     

Diterpenoids ofPulicaria salviifolia. III. The structure of salvicinin

The new diterpene acid salvicinin has been isolated from the epigeal part ofPulicaria salviifolia and its structure has been established as 15-acetoxy-6-hydroxy-trans-cleroda-3,13-dien-19-oic acid. A capacity of salvicinin for undergoing lactonization in the presence of acetic anhydride has been revealed, and the lactone formed has been isolated and chracterized.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Fax (3712) 62 73 48. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 246–249, March–April, 1994.     

Structure of diptocarpilidine

Diptocarpilidine (bp 193–194° (4 mm)) has been isolated from the epigeal part and seeds ofDiptychocarpus strictus (Fisch) Trautv., and its structure has been established as 1-cyano-6-methylsulfinylhexane.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–86, January–February, 1984.     

Polysaccharides ofPolygonatum. VI. A study of the structure of a glucomannan fromPolygonatum sewerzowii by13C NMR spectroscopy,electron microscopy,and x-radiography

A phytoecdysteroid, sileneoside D, has been isolated from the roots ofSilene brahuica Boiss. and it has been shown to be ecdysterone 3-O--D-galactopyranoside.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 741–744, November–December, 1984.     

Quantitative determination of the alkaloids ofAnabasis aphylla by thin-layer chromatography

Summary A chromatographic method has been developed for the quantitative determination of the alkaloids ofAnabasis aphylla — anabasine, aphylline, lupinine, aphyllidine, and anabasamine — and also pachycarpine in the mixture of reduction products of the high-boiling fraction of alkaloids, in a thin layer of alumina.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 772–776, November–December, 1976.