The preparation and characterisation of dichloro(1,2,4-trithia-3-azabut-2-ene)gold(III), AuCl2(S3N)

Deprotonation of heptasulphurmonoimide at −78°C using BuLi followed by reaction with HAuCl₄ yields AuCl₂(S₃N), in moderate yield (21%), characterised by IR/Raman and UV/Vis spectroscopies.     

Synthesis of peptides based onβ-(N1-uracilyl)-α-alanine

The synthesis of peptides which include a DL--(N₁-uracilyl)--alanine (DL-willardiine) residue as an N-terminal or C-terminal group was investigated, dipeptides of DL-willardiine with glycine and L-tyrosine were obtained, and DL-willardiyl-DL-willardiine was synthesized; the latter is the simplest representative of the family of monotonic homopeptides which contain, as a repeating side substituent, a natural nucleic base capable of participation in intermolecular interactions of the complementary type.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 404–408, March, 1971.     

Zur Magnetochemie des zweiwertigen Silbers Neue Fluoroargentate(II): Cs2AgF4, Rb2AgF4 und K2AgF4

Magnetochemistry of Divalent Silver. New Fluoroargentates(II): Cs₂AgF₄, Rb₂AgF₄, and K₂AgF₄ Hitherto unknown blue compounds Rb₂AgF₄ and Cs₂AgF₄ are prepared. Guinier patterns show, that Cs₂AgF₄ cristallise in the K₂NiF₄ structure (a = 4.58₁, c = 14.19₂ Å). The structure of the Rb-compound is still unknown. The magnetic behaviour of K₂AgF₄, Rb₂AgF₄, and Cs₂AgF₄ is discussed.     

Effect of a Competing n Donor on the Rate of AlCl3-Catalyzed Diels-Alder Reaction of 9,10-Dimethylanthracene with Maleic Anhydride

The catalytic effect of AlCl₃ on the Diels-Alder reaction of 9,10-dimethylanthracene with maleic anhydride is dramatically weakened on addition of a competing n donor, dibutyl ether. The n,v complex of aluminum chloride with dibutyl ether is considerably more stable than the complex with maleic anhydride; therefore, the catalytic effect is suppressed even at comparable concentrations of these n donors.     

Kinetic Aspects of Dimethylamine Hydroxyethylation in the Presence of Water

The kinetics of dimethylamine hydroxyethylation at an ethylene oxide : dimethylamine : water molar ratio of 1 : 3 : (0.1–0.5) was studied in the temperature range 20–50°C. A kinetic model of the reaction, which adequately describes the experimental data, was suggested.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005, pp. 687–689.Original Russian Text Copyright © 2005 by Danov, Kolesnikov, Efremov, Mezhenin.     

Determination of four nitroimidazole residues in poultry meat by liquid chromatography-mass spectrometry

A multi-residue liquid chromatography-mass spectrometry (LC-MS) assay method is described for the determination of four nitroimidazoles in poultry muscle. The extraction procedure is based on liquid-liquid extraction with ethyl acetate followed by an evaporation step. A deuterated internal standard is used. The LC separation was made on a C18 bonded silica column with an aqueous formic acid (0.2%) solution-methanol-acetonitrile (81:13:6) mobile phase. Following electrospray ionization, the protonated molecular ion [M+H]+ is obtained for each compound. Monitoring several ions for each nitroimidazole provides the specificity required for confirmatory assay. Validation of the method was performed to estimate linearity, intra-day and inter-day repeatability, accuracy and detection limit. The present method is capable of identifying nitroimidazole residues in muscle at levels below 5 microg/kg.     

Kinetics of the hydroxylation of N-picryl-4-[4-(dimethylamino)styryl]pyridinium salts by molecular oxygen in acetonitrile

The reactions of N-picryl-4-[4-(dimethylamino)styryl]pyridinium salts with molecular oxygen in the presence of 4-[4-(dimethylamino)styryl]pyridine (DASP) in acetonitrile proceeds with the formation of DASP picrate. The reactions are first-order relative to the salt cation, molecular oxygen, and the catalyst (DASP). L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine, 70 R, Lyuksemburg ul., Donetsk 340114, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 5, pp. 286–289, September–October, 1998.