BF3·Et2O catalyzed intramolecular cyclization of diethyl 2-(dialkoxyphosphorylethynyl)-2-arylaminomalonates to 3-phosphonylated indoles

The boron trifluoride diethyl etherate catalyzed intramolecular cyclization of diethyl 2-(dialkoxyphosphorylethynyl)-2-arylaminomalonates afforded a series of novel 3-phosphonylated indoles, diethyl 2-[3-(dialkoxyphosphoryl)-1H-indol-2-yl]propanedioates. Decarboxylation of the latter compounds resulted in the formation of ethyl 2-[3-(dialkoxyphosphoryl)-1H-indol-2-yl]acetates.     

Scaling Behavior of Spectra of Protons,Deuterons, and Tritons Produced with High Transverse Momenta in pA and 12CA Collisions

JETP Letters - The first data on the yield of the lightest nuclear fragments (protons p, deuterons d, and tritons t) with high transverse momenta pT at an angle of 40° in the laboratory...     

Phosphorylation of aminomalonates

The reactions of chloroethynylphosphonates with aromatic secondary aminomalonates occur as classic nucleophilic substitution of chlorine atom at the sp-hybridizied carbon atom to form new phosphorylated 2-arylaminomalonates, diethyl esters of 2-(diethoxyphosphorylethynyl)-2-arylaminomalonic acids. Nonobservance of chemo- and regioselectivity was revealed when using cyclohexyl- and benzylaminomalonates.     

Synthesis of nanodispersed anatase by tetrabutoxy titanium hydrolysis

Nanodispersed titanium oxyhydrate was obtained by tetrabutoxy titanium hydrolysis in the presence of a chelating agent, acetylacetone. The introduction of a chelating agent to tetrabutoxy titanium hydrolysis in a water–ethanol mixture allows one to control the hydrolysis rate. According to X-ray powder diffraction data, amorphous titanium oxyhydrate after annealing at 400°C transforms to anatase, the crystallites of which are 6.2–8.4 nm in size. Transmission electron microscopy showed that the anatase particles are close to spheres 5–9 nm in diameter. The amorphous materials were studied by differential thermal analysis, thermogravimetric analysis, and mass spectrometric analysis of released gases. The benzene adsorption by the produced materials was determined. The nitrogen adsorption isotherms of two samples were constructed, and the specific surface area of the anatase particles and the pore size were found (148.5 and 98 m²/g, and 4.4 and 4.0 nm, respectively).     

Crystal structure and magnetic susceptibility of (CuInSe<Subscript>2</Subscript>)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>(2MnSe)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>

The crystal structure of samples in the (CuInSe₂)_{1 ? x} (2MnSe) _x system at room temperature and their magnetic susceptibility in the temperature range 77–1000 K are investigated. It is established that compositions with concentrations 0≤ x ≤ 0.2 form solid solutions with a tetragonal structure, space group I \(\bar 4\)2d (122). The specific magnetic susceptibility χ of samples with 0.1 ≤ x ≤ 0.4 at 77 K lies in the range 9 × 10^?4?1.6 × 10^t-3cm³/g. The temperature dependence of the inverse magnetic susceptibility of the sample with x = 0.4 suggests the presence of a component with antiferromagnetic ordering and a reliably measured Néel temperature that is characteristic of MnSe. The dependences χ = f(T) of the compositions with x = 0.1, 0.2, 0.3, and 0.4 indicate the occurrence of magnetic phase transitions with a change in the spin state.     

Low frequency fluctuations in a multimode semiconductor laser with optical feedback

We study a multimode semiconductor laser subject to a moderate optical feedback. The steady state is destabilized by either a simple Hopf bifurcation leading to in phase dynamics or by a degenerate Hopf bifurcation leading to antiphase dynamics. The degenerate bifurcation is also a source of multiple coexisting attractors. We show that a simple interpretation of the low frequency fluctuations in the multimode regime is provided by a chaotic itinerancy among the many coexisting unstable attractors produced by the degenerate Hopf bifurcation.     

Dynamic properties of some polymer materials in loading and unloading

A series of quasi-static tests have been carried out on kapron fiber, vinyl plastic, and fluoroplastic specimens with small cross sections. Stress-strain diagrams have been obtained at strain rates from 1 · 10^–3 to 1 · 10² sec^–1. In the experiments the strain rate changed sign, which corresponded to loading and unloading. In each regime the strain rate remained constant. The experimental data are analyzed using the model of a standard linear viscoelastic solid.Mekhanika Polimerov, Vol. 3, No. 1, pp. 118–122, 1967     

Characteristics of the hydrous titanium dioxide-anatase phase transformation during hydrothermal treatment in aqueous solutions

The transformations of hydrous titanium dioxide, prepared by thermal hydrolysis of titanium(IV) compounds in sulfuric acid solutions, during hydrothermal treatment (150–240°C) in water were studied. The dispersivity and the chemical compositions of the samples obtained determined depending on the synthesis conditions (the composition) of hydrous titanium dioxide and the heat treatment temperature.     

Alkali metal 2-(1-adamantyl)ethynethiolates: Synthesis and reactions with electrophilic reagents

Treatment of ethyl 2-[1-(1-admantyl)ethylidene]hydrazine-1-carboxylate with thionyl chloride gave 4-(1-adamantyl)-1,2,3-thiadiazole which readily underwent decomposition by the action of strong bases with formation of alkali metal 2-(1-adamantyl)ethynethiolates. The latter were brought into reactions with proton donors and benzyl halides.     

Calculation of distribution functions for two-component rigid-sphere molecules of a fluid

Analytical expressions are derived and a computational algorithm and program for calculating distribution functions of rigid spheres g _ij (r) necessary for calculations of the thermodynamic parameters of a binary fluid mixture are developed in the context of perturbation theory using the procedure based on the inversion of the Laplace transform for functions rg _ij (r) obtained from the Percus–Yevick equation.