Oxidative nitration of the amino group: synthesis of dinitramide and cyanonitramide salts

A convenient preparative method for the synthesis of potassium dinitramide and cyanonitramide salts was developed. The method involves reactions of nitramide or cyanamide with KNO₂ and PhI(OAc)₂ or PhIO in methanol.     

Tomographic reconstruction of the OH*-chemiluminescence distribution in premixed and diffusion flames

A fast tomographic reconstruction device has been developed to detect the two-dimensional distribution of the chemiluminescence of OH^* in the reaction zones of flames. In the set-up, special emphasis was placed on the applicability of the technique to turbulent flames. A spatial resolution of the system, <1–2 mm, and an exposure time of 100–200 μs are required to resolve the chemiluminescence signal of OH^* originating from the folded flame front of a turbulent flame.     

Chemosensitive properties of poly-4,4′-dialkoxy-2,2′-bipyrroles

Chemosensitive properties of 4,4′-dimethoxy-2,2′-bipyrrole and 4,4′-dibuthoxy-2,2′-bipyrrole were investigated. These new conductive polymers were polymerized by cyclic voltammetry on the platinum and gold interdigitated electrodes designed for 2- and 4-point measurement of lateral conductivity. Thus, obtained polymers demonstrated high sensitivity to HCl in the parts per million concentration range. Kinetics of the gaseous HCl influence on the ratios of conductivities measured by 2- and 4-point techniques was analyzed. Some response of the polymers conductance towards NH₃, NO and oxygen was also observed, but with much lower sensitivity than towards HCl. In aqueous solutions, the polymer conductivity was pH dependent; in comparison with 4,4′-dibuthoxy-2,2′-bipyrrole, the conductivity range of the methoxy derivative was shifted to acidic range for about two pH units. A possibility to use the pH dependence for the development of enzymatic biosensors with pH transducing was demonstrated.     

On exotic hybrid meson production in γ*γ collisions

We present a theoretical study of exotic hybrid meson (J^PC=1^- +) production in photon-photon collisions where one of the photons is deeply virtual, including twist two and twist three contributions. We calculate the cross section of this process, which turns out to be large enough to imply sizeable counting rates in the present high luminosity electron–positron colliders. We emphasize the importance of the πη decay channel for the detection of the hybrid meson candidate π₁(1400) and calculate the cross section and the angular distribution for π η pair production in the unpolarized case. This angular distribution is a useful tool for disentangling the hybrid meson signal from the background. Finally, we calculate the single spin asymmetry associated with one initial longitudinally polarized lepton.     

Viscosity of Cellulose Ether Solutions as Influenced by Mechanical Impact Intensity

Structuring and viscosity of solutions of cellulose derivatives as influenced by mechanical treatment under high shear stresses were studied.     

Fast method for quantum chemical calculations of large molecules with the approximation of the DFT Hamiltonian

The fundamentally new method NESE is proposed for quantum chemical calculations of large molecules, which employs the approximation of the Hamiltonian of the commonly used DFT method and is as fast as the AM1 and PM3 semi-empirical methods or the DFTB method. The parameters for the new method were chosen by the least-squares method based on the comparison of its matrix elements with the reference DFT/PBE Hamiltonian. The initial non-iterative version NESE-0 was computer-implemented and approved on many thousands of various molecules containing H, C, N, and O atoms. The NESE-0 method moderately outperforms the DFTB approach and is an order of magnitude better than the AM1, PM3, and PM6 levels in reproducing the one-electron energies calculated in terms of the DFT/PBE.     

On the Run-Up for Two-Dimensional Shallow Water in the Linear Approximation

A linear tsunami model is considered and the influence of the source parameters on the run-up is studied.

     

Tetraalkylammonium salts of naphthimide and its halo and nitro derivatives

Synthesis of tetraalkylammonium salts of naphthimide and its derivatives was studied     

Kinetics and thermochemistry of the [2π+2σ+2σ]-cycloaddition of quadricyclane with 2,3-dicyano-1,4-benzoquinone

Two-stage [2π+2σ+2σ]-cycloaddition of quadricyclane ( 2 ) with 2,3-dicyano-1,4-benzoquinone ( 1 ) with a huge difference in the activity of two reaction centers has been studied. In the first stage (kinetic control), the cycloaddition of 2 takes place on the activated С₂=С₃ bond of 1 to form the monoadduct 3 , and in the second stage the cycloaddition of 2 on the С₅=С₆ bond of the monoadduct 3 occurs by 6 orders of magnitude lower with the formation of bisadduct 4 . The structures of adducts 3 and 4 have been proved by NMR data and the X-Ray method, respectively. The kinetics of the first and second stages, the enthalpy of dissolution of 1 in the π-donor solvents, and the enthalpy of the reaction 1+2→3 have been measured.