Voprosy khimii i khimicheskoi tekhnologii (Issues of Chemistry and Chemical Technology)

8-12

Authors: K.S. Didenko, N.V. Kozak, V.V. Klepko

N-(2-methylphenyl)-2-oxoazepane-1-carboxamide (ε-caprolactam blocked o-tolyl isocyanate) was obtained via the interaction between o-tolyl isocyanate and ε-caprolactam. The influence of reaction conditions (in bulk or in solution) on the purity and thermal properties of the product was investigated. IR and NMR spectroscopy were used to study the structure of obtained product. To identify the deblocking temperature, the thermogravimetry was used. The reaction of blocking of o-tolyl isocyanate by ε-caprolactam proceeds with the formation of N-(2-methylphenyl)-2-oxoazepane-1-carboxamide both in bulk and in the solution. This is confirmed by the appearance of new absorbance bands of С=О stratching vibration at 1710 сm-1, N-H bending vibration at 1550 cm-1, and the deficiency of NCO-group bending vibration at 2275 cm-1 in the IR-spectrum of N-(2-methylphenyl)-2-oxoazepane-1-carboxamide. The NMR spectra of the product coincide. The yield of the product obtained in bulk is equal to 80-85% while in solution it is more than 95%. The temperature of the thermal dissociation of blocked o-tolyl isocyanate lies in the temperature range of 110 to 120оС.

18-35

Authors: Yu.G. Shermolovich, S.V. Zasukha

Literary data on the synthesis methods and chemical properties of α-fluoro- and α-fluoromethyl- methylenbisphosphonic acids derivatives have been summarized. The derivatives of (α-fluoro)methylenbisphosphonic acid are obtained by the following methods: Michaelis-Bekker reaction – from halogenosubstituted α-fluoromethylphosphonates; electrophilic fluorination of the derivatives of methylenbisphosphonic acid using perchlorylfluorite, fluorine, acetylhypofluorite, N-fluorodibenzosulfonimid and Selectfluor as reagents; nucleophilic fluorination of aryl(α-hydroxy)methylenbisphosphonic acid esters by morpholino sulfur trifluoride; reaction of α-halogeno-α-fluoromethylphosphonates and electrophilic agents in the presence of base; and, finally, phosphorylation of (α-fluoro)phosphonoacetate. A special attention was drawn to the usage of these compounds for the synthesis of fluorocontaining nucleotides analogs. The derivatives of (α-fluoro)methylenbisphosphonic acid react in the presence of a base with alkylhalogenides, aldehydes, ketones, α,β-unsaturated ketones, esters, sulfones, sulfoxides and phosphonates. The hypohalogenation of (α-fluoro)bisphosphonates gave halogenosubstituted bisphosphonates. The interaction with magnesium ethoxide resulted in α-fluorophosphonate. Acidic hydrolysis or reaction of (α-fluoro)methylenbisphosphonic acid tetraesters with trimethylhalogensylan and methanol resulted in formation of (α-fluoro)methylenbisphosphonic acids which form ammonium salts with amines. The synthesis of α-fluoromethyl-methylbisphosphonic acids is based on the reaction of N-(arylsulfonyl)trifluoroacetimidoyl chloride, N-trichloroacetylfluoracetimidoyl and di- or trifluoroacetonitryl with dialkylphosphite; reaction of 1,1-dichloro-2,2,2-trifluoroethylisocyanate and triethylphosphite; acylation of trialkylphosphite by trifluoroacetic anhydiride; double phosphorylation of fluoroacetonitril by diethylphosphite in conditions of radical reaction.

40-47

Authors: Y.V. Kalashnykov, A.N. Abramova, A.N. Kalashnykova, N.V. Nikolenko

Chemical transformations are studied that occur during the heat treatment of a new precursor of iron-molybdenum catalyst – ammonium molybdoferrates(II). It has been established that the consecutive decomposition of ammonium molybdoferrates(II) proceeds during the heat treatment in an oxidizing atmosphere which is accompanied by the formation of iron(II) molybdate together with an excess of molybdenum trioxide and its further oxidation resulting in the formation of iron(III) molybdate. It has been shown that a considerable amount of impurities may be entrapped into precipitate from concentrated solutions as a result of enhanced rate of solid phase formation. The thermal decomposition of these impurities proceeds up to a temperature of 500 0C in an oxidizing atmosphere and up to a temperature of 700 0C under nitrogen atmosphere.

51-58

Authors: V. Korovin, Yu. Shestak, A. Valyaev

The features of changing the porous characteristics of styrene-divinyl benzene matrix of the Levextrel-type resin containing try-butylphosphate (TVEX-TBP) in the wide range of the concentrations of extractant and cross-linking agent are defined using mercury poroscopy. With increasing the extractant content and cross-linking degree, a total pore volume increases from 0.30 up to 1.75 cm3/g while a specific pore surface increases from 59.30 up to 237.76 m2/g, respectively. Using fractal analysis, the pore ranges were defined in which the self-similarity of the matrix porous structure remains. The porous space surface and volume in TVEX-TBP matrix were shown to have fractal properties. The number of pore radius ranges, where the self-similarity is maintained, is 2-4 for the surface and 2-5 for the volume of porous space depending upon TVEX synthesis conditions. Fractal dimension changes from 2.06±0.002 up to 3.06±0.01 for the porous space surface and from 1.97±0.02 up to 2.99±0.001 for the porous space volume. The total pore ratio is calculated for which the self-similarity remains for the surface and volume of the matrix porous space depending on the concentrations of extractant and cross-linking agent. Almost the whole surface of TVEX matrix porous space (i.e. 81.1-100%) has fractal properties. The self-similarity of the porous space volume is maintained at the level of 24.5-100% of pores and increases with an increase in the extractant content, showing a minimum at a cross-linking degree of 30-50% DVB.

68-73

Authors: T.L. Malysheva

In this work the influence of chemical structure of a polymer based on semicrystalline polyurethane elastomer (PU) and vinyl chloride (i.e. pоly(vinylchloride-co-vinyl acetate), chlorinated poly(vinyl chloride)) оn supramolecular structure, cohesion and adhesion properties of the composites has been studied. It was shown that the strong interfacial hydrogen bonding between carbonyls of PU based on poly(1,4-butanediol adipate) and α-hydrogen of chlorinated polymers in their blends initiate a formation of a mixed phase with loosely packed macromolecules that results in reducing the mechanical and adhesion strength of the composites. The strengthening of intramolecular H-bonds in elastomer by increasing polar urethane-urea segments content or the replacement of poly(1,4-butanediol adipate) segments onto less compatible poly(ethylene glycol adipate-co-1,4-butanediol adipate) suppress the interface interactions and the formation of mixed phase. This leads to an improvement in cohesion and adhesion properties of the composites. The composites with 30 wt.% of pоly(vinylchloride-co-vinyl acetate) content are characterized by nanoheterogeneous structure and enhanced adhesion properties compared with PU.