Synthesis of polyfunctionalized methylphosphine oxides

N,N-Dialkylamino(diphenylphosphoryl)chloromethanes, a new type of organophosphorus compounds, were synthesized. On dissolving in polar and low polar solvents, N,N-dialkylamino(diphenylphosphoryl)chloromethanes dissociate spontaneously with the P??C bond cleavage to form the diphenylphosphinite anion Ph₂PO^?. This was confirmed by the reaction of N,N-dimethylamino(diphenylphosphoryl)chloromethane with electrophilic substrates to form the corresponding addition or substitution products of Ph₂PO^?. The capability of spontaneous generating the diphenylphosphinite anion considers accessible N,N-dimethylamino(diphenylphosphoryl)chloromethane as a synthetic equivalent of the diphenylphosphinite anion.     

Synthesis and study of the structure of cage-like metallosiloxanes with pair combinations of 3d transition and alkaline earth metals

The selective replacement of Na ions in cage-like (Cu,Na) organosiloxanes in reactions with divalent metal halides was studied. The sandwich-like isomer [PhSiO₂]₆Cu₄Na₄[PhSiO₂]₆ forms the corresponding bimetallic complexes [PhSiO₂]₆Cu₄M₂[PhSiO₂]₆ (M = Cu, Zn, Mg, Sr, Ba) retaining a sandwich-like structure (in 60–90% yields) regardless of the metal ion size in MCl₂. Under similar conditions, the reactions of the globular isomers [RSiO₂]₁₂Cu₄Na₄ (R = Ph, Me, Vin) with CuX₂ (X = Cl or Br) afforded insoluble polymer products. The reaction in dioxane or THF in the presence of DMSO gave the crystalline globular-type metal complexes [RSiO₂]₁₂Cu₄[CuX]₄, in which Na ions are replaced by CuX groups. The compositions and structures of the synthesized metal complexes were studied by X-ray diffraction, elemental analysis, and destructive silylation combined with gel permeation chromatography and ¹H NMR spectroscopy.     

Polymerization of hexaethylcyclotrisiloxane during the synthesis of carbofunctional oligo(diethylsiloxane diols)

Oligo(diethylsiloxane diols) carrying β-oxyethoxymethyl terminal groups are synthesized for the first time by the cationic polymerization of hexaethylcyclotrisiloxane in the presence of bis(β-oxyethoxymethyl)tetramethyldisiloxane with the use of sulfuric acid or the cationite KU-23 as a catalyst. It is shown that, along with oligo(diethylsiloxane diols), the products of rearrangement of diethylsiloxane chains, such as octaethylcyclotetrasiloxane and higher cycles, are formed. The reaction of dipotassium salts of oligo(diethylsiloxane diols) with chlorosilanes of the formula ClSi(CH₃)₂CH₂O(CH₂)₂OCOCH₃ yields acetoxy-terminated oligomers that contain octaethylcyclotetrasiloxane and higher cycles as well.     

Systematic procedure for reduction of kinetic mechanisms of complex chemical processes and its software implementation

Feasibility of multidimensional hydrodynamic modeling depends critically on the availability of accurate reduced kinetic mechanisms of physical and chemical processes taking place in the system. Such mechanisms should describe the processes under consideration within a specified error tolerance in the range of initial conditions of interest while keeping the number of species and reactions as small as possible. We have developed an advanced tool for reduction of detailed kinetic mechanisms with a minimal human effort. The tool includes 10 reduction and 2 analysis methods which are based on the results of zero-dimensional modeling. The methods can be combined and applied in sequence. The reduction tool has been implemented as a part the Chemical Workbench computational package and has been tested for a number of large kinetic mechanisms of gas-phase processes. Using this tool, we reduced the mechanism of tar gasification from 177 species and 879 reversible reactions to only 83 species and 278 reactions, while the mechanism of methane combustion initially involving 127 species and 1,206 reactions was reduced to 42 species and 173 reactions.     

Synthesis and NMR spectroscopy of 1,3,3,5,5-pentaalkoxy-1-chlorocyclotriphosphazenes

A series of pentaalkoxychlorocyclotriphosphazenes was synthesized. The spectral characteristics of the synthesized compounds (³¹Р, ¹H, ¹³С NMR) were studied. It was shown that the complexity of the NMR spectra of pentaalkoxychlorocyclotriphosphazenes is associated with the magnetic nonequivalence of the phosphorus atoms in the triphosphazene cycle and the hydrogen and carbon atoms in the alkoxy groups on these phosphorus atoms, as well as the cis/trans isomerism of the latter groups.     

Partial oxidation of kerosene in plume microwave discharge

The effect of atmospheric-pressure microwave torch discharge plasma on the process of partial oxidation kerosene (C₁₁H₂₂) with air oxygen was examined. The characteristics of the process were studied. It was shown that the yield of the final product (synthesis gas) at energy input in the form of plasma is higher than that upon thermal input via burning a portion of the fuel. The mechanism of the phenomenon is discussed on the basis of comparison of the experimental results with numerical simulation data.