Reactions of 4-Aryl-2-hydrazino-3-nitro-6-R-quinolines with HNO2

The reaction of 4-aryl-2-hydrazino-3-nitro-6-R-quinolines with NaNO₂ in AcOH gives the corresponding tetrazolo[1,5-a]quinolines. In contrast to tetrazolo[1,5-c]pyrimidines they cannot be converted to 6-R-4-phenyl[1,2,5]oxadiazolo[3,4-b]quinoline-3-oxides by heating in THF, toluene, or AcOH. Total energy quantum-chemical calculations using the MINDO/3 and MNDO methods show that [1,2,5]oxadiazolo[3,4-b]quinoline-3-oxides are significantly higher in energy (230-280 kcal/mol) than the mentioned tetrazolo[1,5-a]quinolines and hence their formation is unlikely.     

Properties of nanocomposites based on crosslinked elastomeric polyurethane and ultrasmall additives of single-wall carbon nanotubes

It is shown for the first time that the addition of ultrasmall amounts of single-wall carbon nanotubes leads to a significant increase in the main mechanical characteristics of the crosslinked poly(urethane urea) elastomer. The elastic modulus and the tensile strength pass through maxima as the nanotube concentration is increased from 0 to 0.018 wt %; at a nanotube concentration of 0.002 wt %, the maximum values of the modulus and strength are higher by factors of 2.5 and 1.5, respectively, than the corresponding values for the unfilled polymer. The thermomechanical, spectral, and structural characteristics of nanomodified elastomers are investigated, and possible causes of change in their mechanical parameters are discussed.     

Chloroarylation and thiocyanatoarylation of itaconic acid

Under conditions of Meerwein reaction and anionarylation the aryldiazonium salts and itaconic acid form 2-chloro(thiocyanato)-2-benzylbutanedioic acids as the chloro- and thiocyianatoarylation products. The reaction is not accompanied by the decarboxylation process and other transformations affecting the carboxy groups of itaconic acid.     

Synthesis of (polycyanoisopropyl)[60]fullerene

The reaction of fullerene with excess 2,2′-azobis(isobutyronitrile) in o-dichlorobenzene at 60°C was studied, and the chemical structure of the reaction product was determined.     

Exact theory of the (Einstein) gravitational field in an arbitrary background space-time

The Lagrangian based theory of the gravitational field and its sources at the arbitrary background space-time is developed. The equations of motion and the energy-momentum tensor of the gravitational field are derived by applying the variational principle. The gauge symmetries of the theory and the associated conservation laws are investigated. Some properties of the energymomentum tensor of the gravitational field are described in detail and the examples of its application are given. The desire to have the total energymomentum tensor as a source for the linear part of the gravitational field leads to the universal coupling of gravity with other fields (as well as to the self-interaction) and finally to the Einstein theory.     

Inflationary stages in cosmological models with a scalar field

Homogeneous isotropic cosmological models with a massive scalar field are studied. It is shown that inflationary stages of evolution are characteristic of most solutions in these models.     

“Dormant” inhibitors of urethane type as controllers of temperature modes of styrene polymerization

Urethanes based on a series of monoisocyanates and phenolic inhibitors of styrene radical polymerization, which release the initial phenolic inhibitor at elevated temperatures, were prepared and characterized. Some of these compounds meet the requirements to “dormant” inhibitors: they sharply decelerate thermally initiated high-temperature polymerization of styrene and do not noticeably affect the rate of low-temperature polymerization in the presence of an inhibiting substance. The possibility of preventing uncontrollable emergency situations by adding these compounds to the initial monomer was confirmed experimentally.     

Formation of new hybrid structures: Fullerene C<Subscript>60</Subscript>–amphiphilic copolymer of <Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone with (di)methacrylates in isopropyl alcohol

New hybrid structures of fullerene C₆₀ and an amphiphilic copolymer of N-vinylpyrrolidone with lauryl methacrylate and triethylene glycol dimethacrylate have been obtained via solubilization of fullerene by individual macromolecules and their micelle-like aggregates that form in isopropyl alcohol. The volume ratios of copolymer and C₆₀ solutions in toluene at which there is suppression of aggregation of fullerene and fullerene–polymer particles and the existence of stable hybrid structures in solution have been found. With the use of absorption electron spectroscopy, it has been shown that, with time, fullerene undergoes binding to donor groups of the copolymer and forms a donor–acceptor complex. According to the data of optical microscopy, fullerene is homogeneously distributed as spherical aggregates in the solid polymer matrix.     

Formation of N–S Bonds in Reactions of 2-[2-Oxo-1-(tosyloxyimino)-2-phenylethyl]pyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one and Its 6-derivatives with Thiourea and Potassium Thiocyanate

Reaction of potassium thiocyanate with 2-[2-oxo-1-(1-tosyloxyimino)-2-phenylethyl]pyrimidin-4-(3H)-one derivatives led to the formation of a new fused heterocyclic system with a common nitrogen atom, substituted 7H-[1,2,5]thiadiazolo[2,3-a]pyrimidin-7-one.