Reactivity of double bonds of substituted <Emphasis Type="Italic">p</Emphasis>-(methacryloyloxy)-<Emphasis Type="Italic">N</Emphasis>-phenylmaleimides in free-radical polymerization

The thermoinduced free-radical polymerization of model systems, namely, methyl methacrylate and N-phenylmaleimide derivatives, has been studied. It has been shown that, in the polymerization of p-(methacryloyloxy)-N-phenylmaleimides, the yield of the polymer and its molecular-mass distribution (mono-or bimodal) and polydispersity depend on the degree of substitution and the nature of a substituent in a double bond of a maleimide fragment. The structure of the maleimide fragment, in turn, determines its capability to copolymerize with the methacryloyl group of a bifunctional monomer as well as the occurrence of chain-transfer and termination reactions.     

Integral representations of generalized axially symmetric potentials in a simply connected domain

We obtain integral representations of generalized axially symmetric potentials via analytic functions of a complex variable that are defined in an arbitrary simply connected bounded domain symmetric with respect to the real axis. We prove that these integral representations establish a one-to-one correspondence between analytic functions of a complex variable that take real values on the real axis and generalized axially symmetric potentials of certain classes.     

Reaction of arenediazonium tetrafluoroborates with 3-(allyloxy)propane-1,2-diol and 2,2-bis(allyloxymethyl)butan-1-ol in the presence of thiocyanates

The reactions of arenediazonium tetrafluoroborates with 3-(allyloxy)propane-1,2-diol and 2,2-bis(allyloxymethyl)butan-1-ol in the presence of the thiocyanate nucleophile were used to obtain 3-(3-aryl-2-thiocyanatopropoxy)propane-1,2-diols and 2-[(allyloxy)methyl]-2-[(3-aryl-2-thiocyanatopropoxy)methyl]-butan-1-ols. Irrespective of reagent ratio, the second allyl fragment of 2,2-bis(allyloxymethyl)butan-1-ol fails to enter thiocyanatarylation. The presence of hydroxy groups in the unsaturated compounds studied render the latter less reactive than allyl derivatives containing no such groups.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 2019–2022.Original Russian Text Copyright © 2004 by Grishchuk, Baranovskii, Kovalskii, Gorbovoi.This revised version was published online in April 2005 with a corrected cover date.     

Reaction of arenediazonium tetrafluoroborates with allyl methacrylate in the presence of the thiocyanate anion

Allyl 2-thiocyanato-2-methyl-3-arylpropionates were obtained by the reaction of arenediazonium tetrafluoroborates with allyl methacrylate in a water-acetone (1: 5) medium, involving thiocyanatoarylation by the C=C bond of the methacrylic fragment. Under the examined conditions, the allylic fragment of the biunsaturated compound does not react.     

Viscosity of concentrated solutions of polystyrene and poly(vinyl acetate) (empirical equations)

The viscosity of solutions of polystyrene with M _w from 2.8 × 10⁴ to 7.8 × 10⁵ in toluene and of poly(vinyl acetate) with M _w from 2 × 10⁴ to 1.4 × 10⁵ in butyl acetate at 30–80°C is measured. The dependence of the activation energy of the viscous flow of the solutions on the molecular weight of the polymers and solution concentration is examined. This dependence is approximated by a cubic polynomial for polystyrene solutions and by a quadratic polynomial for poly(vinyl acetate) solutions. The dependences of the solution viscosity on the concentration, molecular weight, and temperature are approximated by exponential equations in which the exponents are sums of polynomials. The coefficients of the polynomials are determined.     

Azolidine-4-thiones,their derivatives and analogs

4-Thioxothiazolid-2-one (isorhodanine) is distinguished from the initial thiazolidine-2,4-dione, and also from rhodanine and other azolid-4-ones, by the highly active C=S group in position 4. When isorhodanine is heated in methanol with various amino compounds, condensation products-substituted 4-iminothiazolid-2-ones-are obtained.For part V, see [10].     

Synthesis of imidazo[4,5-e][1,4]diazepine-8-one

We have developed a method for synthesis of 1-methyl-4,5,7, 8-tetrahydro-6H-imidazo[4,5-e][1,4]diazepin-8-one. We have shown that in intramolecular cyclization of N-(2-hydroxyethyl)- or N-(2-chloroethyl)amides of 1-methyl-4-aminoimidazolyl-5-carboxylic acids it is not the corresponding tetrahydroimidazo[4,5-e][1,4]diazepin-8-ones which are formed but rather the isomeric 4-amino-5-(oxazolin-2-yl)imidazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1203–1206, September, 1993.     

Adsorption-desorption properties of bazalt tuff and catalytic activity of acido complexes of palladium(II) and copper(II) in the reaction of carbon(II) oxide oxidation with oxygen

Desorption of palladium(II) and copper(II) from the K₂PdCl₄-Cu(NO₃)₂-KBr/H-BT-6 catalysts, in which bazalt tuff from various deposits subjected to acid modification is used as carrier, was studied.