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981.
L. M. Khalilov O. V. Shitikova R. I. Khusnutdinov Z. S. Muslimov U. M. Dzhemilev A. A. Panasenko G. A. Tolstikov 《Russian Chemical Bulletin》1990,39(3):484-488
The structures of the dimerization products of spiro(bicyclo[2.2.1]hepta-2,5-diene-7,1-cyclopropane) have been solved using13C NMR spectroscopy and their stereochemical assignments made. The methylene carbon atom signals for the spirocyclopropane fragment can be used as diagnostic signals in making the stereochemical assignments.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 559–564, March, 1990. 相似文献
982.
Neal O. Brace 《Journal of fluorine chemistry》1981,18(4):515-524
A completely fluorinated ester of the type RFCO2CF2RF′ was obtained from reaction of silver 3,6,9-trioxa-F-undecanoate and iodine with a diluent at 130°. This new substance resembled closely the previously prepared 1,1-dichloro-F-alkyl esters and was hydrolytically and thermally labile. Substitution products, RFCOY (Y = nucleophile) and pyrolysis products, RFCOF and RF′COF were isolated and characterized. It appears probable that the acyl hypoiodite and the iodo-F-alkane reacted by an SEi-type process to give the completely fluorinated ester. 相似文献
983.
Gulyakevich O. V. Mikhail'chuk A. L. Akhrem A. A. 《Chemistry of Heterocyclic Compounds》1995,31(2):235-236
Institute of Bioorganic Chemistry, Belarus' Academy of Science, Minsk, 220141. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 266–267, February, 1995. Original article submitted December 15, 1994. 相似文献
984.
The sorption of Hg(II), Cd(II), and Pb(II) as anionic complexes on the solid phase of polyacrylonitrile fiber filled with the AV-17 anion exchanger from NaCl and KI solutions and their complexation with 4-(2-pyridylazo)resorcinol (PAR) and dithizone were studied. A test method was developed for the individual determination of Hg(II), Cd(II), and Pb(II) from one sample on three support disks. From the same solution, by the successive sorption on two disks from a 0.2 M NaCl solution, mercury was determined with dithizone and cadmium was determined with PAR. After the addition of a KI solution and sorption on the third disk, lead was determined with PAR. Using the added-found method, the procedure was approved in the analysis of natural sodium chloride water. The detection limit was 0.01 mg/L for Hg(II) and 0.02 mg/L for Cd(II) and Pb(II) for a volume of the analyzed sample of 25 mL. The time of the analysis of five or six samples (determination of three elements) is no longer than 50 min. 相似文献
985.
986.
Mass spectra of carbohydrate methyl ethers of different types and other monosaccharide derivatives have been measured. Fragmentation patterns of these compounds, characteristic features of their mass spectra and potential analytical importance of mass spectrometry for structural study in the carbohydrate field are discussed. 相似文献
987.
Zusammenfassung Die früheren Befunde über den Gehalt an Isopelletierin in der Granatapfelbaumrinde wurden an 5 weiteren Rindenproben bestätigt. Isopelletierin wurde zu 30 bis 40% in den Gesamtalkaloiden aufgefunden.Versuche zeigen, daß das opt.-akt. Methylisopelletierin in schwach alkalischer Lösung bei 20° wohl racemisiert, aber nicht zersetzt wird.I.:F. Galinovsky undO. Vogl, Mh. Chem.83, 1055 (1952). b) II.:F. Galinovsky, G. Bianchetti undO. Vogl, Mh. Chem.84, 1221 (1953). c) III.:F. Galinovsky undF. Höllinger, Mh. Chem.85, 1012 (1954). 相似文献
988.
G. O. Schulz R. Milkovich 《Journal of polymer science. Part A, Polymer chemistry》1984,22(7):1633-1652
Copolymerization studies of methacrylate-terminated polystyrene macromonomers (M1) with several comonomers (M2) verified the modified kinetic scheme and permitted prediction of graft polymer compositions and structures. Instantaneous and cumulative copolymer compositions, average graft distributions, and grafts per molecule are predicted from FORTRAN IV or BASIC programs. The r2 relative reactivity ratios determined from styrene copolymerization (0.61) or from low conversion acrylic monomer in aqueous suspension (~0.4) had good agreement with literature values (about 0.6 and 0.4, respectively). Decreased macromonomer reactivity determined at high acrylic monomer conversions was attributed to phase separation phenomena. The Macromers also exhibited lower reactivity than predicted when copolymerized with acrylic monomers in DMSO/benzene solutions (r2 ~ 0.8). 相似文献
989.
The ratio of endo-CHO:exo-CHO in the Diels-Alder addition of a trans-αβ-unsaturated aldehyde to cyclopentadiene can be changed from 1:2 to 8:1, depending on temperature and BF3-catalysis. 相似文献
990.
Calculation was made of the electronic structure of copper and platinum phthalocyanine crystals, and their deformation potentials were determined. The calculation was carried out on an electronic computer using the following basic assumptions: Bloch wave functions; Hückel molecular orbitals; Slater atomic orbitals. The pattern of the band spectrum obtained was used qualitatively to explain some kinetic relationships recently observed in copper and platinum phthalocyanines. 相似文献