Gas-chromatographic identification of fluorine-containing organic compounds

The gas-chromatographic retention of a series of fluoroalkylarenes on the standard nonpolar polydimethylsiloxane stationary phase OV-101 was characterized, and the retention indices of these compounds were determined. It was found that large negative values of the homological increments of these constants can serve as a sign of fluorine derivatives that contain no less than three fluorine atoms per molecule. The retention indices on polar inorganic sorbents, the silica gels Silipor 75 and Silipor 600, were chosen as the second chromatographic parameter. On these sorbents (unlike partition separation), the nonadditivity effect of the retention indices of polyfunctional organic compounds with respect to their simpler structural analogs was found for the first time. It was found that a mutual correlation between indices for this combination of a phase and a sorbent was lower than that for the combinations of phases with different polarities; this fact is responsible for the higher information content of this combination for the identification of compounds from this class.     

Structural and Kinetic Relations Holding in the Halogen Abstraction from Organohalogen Compounds by Alkyl Radicals

The relative rate constants were determined, and the absolute rate constants were estimated, for halogen transfer from N,N-dihaloarenesulfonamides, (dichloroiodo)arenes, benzyl bromides, and arenesulfonyl chlorides to cyclohexyl radical and from N,N-dihaloarenesulfonamides to benzyl radical. Polar effect of the substituent was found to be the main factor determining the rate of halogen transfer from benzyl bromides and arenesulfonyl chlorides; it increases with rise in the electrophilicity of the organohalogen substrate due mainly to charge distribution in the transition state.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 33–39.Original Russian Text Copyright © 2005 by Dneprovskii, Eliseenkov, Chulkova.     

Identification of the products of nonregioselective organic reactions by chromatography-mass spectrometry: Chloro derivatives of dialkyl ethers

The possibilities of GC-MS identification of the products of free-radical chlorination of dialkyl ethers are considered. The principal feature of this problem was the absence of appropriate reference information (both mass spectra and GC retention indices) for chloro derivatives of ethers. It was shown that all monochloro and selected dichloro derivatives can be identified on the basis of joint interpretation of their mass spectra combined with evaluating the retention indices using different additive schemes.     

The growth of a single crystal of Sr3CuIrO6 and its magnetic behavior compared to polycrystals

We have grown single crystals of the psuedo-one-dimensional compound Sr₃CuIrO₆, a K₄CdCl₆-derived monoclinic structure with Cu-Ir chains along the [101] direction. We present the ac and dc magnetization behavior of the single crystals in comparison with that of the polycrystalline form reported earlier. There is a distinct evidence for at least two magnetic transitions, at 5 K (T ₁) and 19 K (T ₂), with different relative magnitudes in the single and polycrystals. The low temperature magnetic relaxation behavior of both the forms is found to be widely different, exhibiting unexpected time dependence.     

Reaction of amidophosphite s with α-hydroxyalkylphosphonates

Conclusions -Hydroxyalkylphosphonates and -hydroxyalkylphosphinates react with the amides and ester amides of phosphorous and phosphonous acids to give the products of either the partial or complete replacement of the amido groups.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1869–1871, August, 1976     

Reactions of dialkyl hydrogen phosphites with phosphorous amides

Russian Chemical Bulletin -     

Identification of the chlorination products of aliphatic ketones by gas chromatography and gas chromatography/mass spectrometry

The differences in the gas chromatographic retention indices of the chlorination products of aliphatic ketones and parent carbonyl compounds (ΔRI) are constant, and their numeric values depend on the number and position of chlorine atoms in the molecule. A simplest version of an additive scheme for the evaluation of retention indexes is developed to identify the chloro derivatives of carbonyl compounds. The order of the chromatographic elution of diastereomeric α,α′-dichloro-k-alkanones (k > 2) is found.