Hydrosilylation of ethylene

Hydrosilylation of ethylene with trialkoxysilanes in the presence of Pt(0) complexes as catalysts affords ethyltrialkoxysilanes in almost quantitative yields. No impurities of vinyltrialkoxysilanes were detected. Experiments and ab initio calculations showed that the Pt(0) catalysts are considerably more active in ethylene hydrosilylation than Pt(II) catalysts.     

Terpenoids from plants of the family Cupressaceae. I. Sesquiterpene alcohols from the needles ofMicrobiota decussata

The sesquiterpene alcohols 5S,8S-germacra-1E,6E-dien-5-ol, (+)--bisabolol, hedycaryol, and -eudesmol and also the previously undescribed alcohols thujopsan-2-ol (I) and microbiotol. Microbiotol is a tricyclic tertiary alcohol with the empirical formula C₁₅H₂₆O, mp 112–113°C, containing in its molecule four tertiary methyl groups and cyclopropane ring.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostock. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 163–169, March–April, 1981.     

Reaction of allylamine with hexylsilane

The reaction of hexylsilane with allylamine is accompanied by the liberation of hydrogen and formation of allylaminosilanes and compounds with the Si-Si bond. The hydrosilylation pathway virtually is not realized. The B3LYP/6-311G** calculations show that all the considered reactions are thermodynamically allowed.     

Proanthocyanidin dimers fromSpiraea hypericifolia

Summary From the bark and roots ofSpiraea hypericifolia L. we have isolated and identified proanthocyanidins consisting of dimers of 3,3,4,5,7-pentahydroxyflavans: a dimer from the bark (B-1) with the 2R:3R configuration of the asymmetric centers of the top half of the molecule and 2R:3S of the bottom half and a dimer from the roots with the 2R:3R configurations of the asymmetric centers of both the top and bottom halves of the molecule.S. M. Kirov Kazakh State University, Alma-Ata. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 735–742, November–December, 1976.     

Oscillations of Magnetic Fluid Column in Strong Magnetic Field

Russian Physics Journal - The paper considers the results of measuring the elastic parameters (ponderomotive elasticity coefficient, oscillation frequency, attenuation coefficient) of the...     

Stability analysis of gyroscopic systems with integral correction

Stability theorems for gyroscopic systems with integral correction under dissipative and nonconservative positional forces are proved. An inertial vertical gyro is used as an example to illustrate the results obtained