Tantalum Dimethyldithiocarbamate Complexes

The reaction of Ta(NMe₂)₅ with CS₂ gave the tantalum(V) dimethyldithiocarbamate complex [Ta(^MeDtc)₄](^MeDtc) (I). An ionic structure of the complex with a dodecahedral coordination of the tantalum atom was determined for toluene (I · Tol) and THF (I · THF) solvates by X-ray diffraction (CCDC no. 1544283 and no. 1544284, respectively). The reaction of I with CH₂Cl₂ leads to exchange of the outersphere anion to give the known complex [Ta(^MeDtc)₄]Cl (II). The cyclic voltammogram of II in CH₃CN exhibits a quasi-reversible transition at E _1/2 =–0.735 V corresponding to the Ta^V/Ta^IV pair.     

Synthesis and structure of trimethylantimony dimethacrylate

The reaction of trimethylantimony with methacrylic acid in the presence of tert-butyl hydroperoxide gave trimethylantimony dimethacrylate Me₃Sb(O₂CCMe=CH₂)₂ whose structure was confirmed by elemental analysis and IR, ¹H and ¹³C NMR, and mass spectra. According to the X-ray diffraction data, the title compound is a trigonal–bipyramidal antimony complex with three methyl group in the pyramid base and two methacrylate ligands in the apices.     

Synthesis of Ph3Bi(O2CR)2 Compounds with Unsaturated Carboxylic Acids and Use of Triphenylbismuth Dicrotonate in the Synthesis of Bismuth-Containing Polymers

Russian Journal of General Chemistry - Triphenylvismuth dicarboxylates Ph3Bi(O2CCH=CHMe)2, Ph3Bi(O2CCH=CHPh)2, Ph3Bi(O2CCH=CHC6H4NO2-m)2, Ph3Bi(O2CCH=CHC4H3O)2, Ph3Bi(O2CCH=CHC6H4OMe-p)2,...     

Single-type differential games with convex integral payoff

Single-type differential games are considered. The problem of taking a phase point to a disk of a fixed radius at a given time is studied. The payoff is the integral of a convex function depending on the norm of the first player’s control.     

Competing reactions of hydrophenylation and phenylation in tetraphenylantimony chloride methyl acrylate palladium chloride system

A new catalytic reaction of the competing phenylation and hydrophenylation in air of methyl acrylate with tetraphenylantimony chloride in the presence of PdCl₂ (0.04 mol per 1 mol of organometallic compound) in acetonitrile at 50°C for 6 h was studied. The yields of methyl cynnamate and methyl hydrocynnamate were 0.73 and 0.27 mol mol^?1 respectively. The products ratio obtained depends slightly on the process duration, the Ph₄SbCl and methyl acrylate ratio, and the structure of Pd salt [PdCl₂, Pd(OAc)₂, Li₂PdCl₄], but significantly on the nature of a solvent (MeCN > DMF > THF). The use of Ph₄SbCl instead of Ph₄SbBr leads to decrease in the yield of methyl hydrocynnamate to 0.04 mol mol^?1. In the reactions of Ph₄SbX (X = F, I, OAc, O₂CEt) the product is not formed at all.     

Synthesis and structures of triphenylantimony oximates

The reactions of triphenylantimony or trimethylantimony with tert-butyl hydroperoxide in the presence of acetone oxime, acetophenone oxime, cyclohexanone oxime, or benzaldehyde oxime afforded monomeric triorganoantimony oximates Ph₃Sb(ON=CMe₂)₂, Ph₃Sb(ON=CMePh)₂, Ph₃Sb[ON=C(CH₂)₅]₂, Ph₃Sb(ON=CHPh)₂, and Me₃Sb(ON=CMe₂)₂ in 87—96% yields. X-ray diffraction analysis demonstrated that Ph₃Sb(ON=CMe₂)₂ and Ph₃Sb(ON=CHPh)₂ have trigonal-bipyramidal structures. An analogous reaction with dimethylglyoxime gave rise to polymeric triphenylantimony dioximate in 96% yield. The reaction with butane-2,3-dione monoxime yielded chelate cyclic bis(triphenylantimony) oxides.     

Mechanochemical synthesis and crystal structure of acetylacetonate complexes with the triangular Mo3Q7 4+ core (Q = S or Se)

Mechanochemical reactions of inorganic polymers ¹ _∞[Mo₃Q₇Br₄] (Q = S or Se) with sodium acetylacetonate hydrate lead to excision of the Mo₃Q₇ ⁴⁺ cluster core giving rise to the cationic complexes [Mo₃Q₇(acac)₃]⁺. Extraction of the reaction mixture with acetone followed by recrystallization from a benzene-hexane mixture afforded the {[Mo₃S₇(CH₃COCHCOCH₃)₃]Br}·2C₆H₆ (1) and {[Mo₃Se₇(CH₃COCHCOCH₃)₃]Br}· · 2C₆H₆ (2) complexes. The structures of complexes 1 and 2 were studied by IR and ¹H NMR spectroscopy and X-ray diffraction. Compound 1 was characterized by electrospray mass spectrometry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1895–1898, November, 2006.     

Simulation of processes in an electrodynamic mass accelerator

Processes in a pulse plasma accelerator used as a mass accelerator are simulated in the magnetohydrodynamic approximation. Numerical calculations elucidate the dynamics of formation of a plasma piston. Two qualitatively different modes of plasma piston formation are identified, and the acceleration of the body in each mode is determined. Calculations show that the plasma dynamics mainly depends on the mass of the working substance, the dependence of plasma conductivity on the thermodynamic parameters, and the electrode cooling scheme.Translated from Matematicheskoe Modelirovanie i Reshenie Obratnykh Zadach Matematicheskoi Fiziki, pp. 201–207, 1993.     

Excitation and development of unstable disturbances in a supersonic boundary layer

The initial-boundary value problem of the development of two-dimensional inviscid disturbances excited by an external unsteady local action, turned on at time t=0, is examined. The spectrum of the problem is investigated by means of the WKB method and numerical calculations, and the asymptotic expansions of the wave packets as t are found. It is shown that, contrary to the conclusions of [4], the inviscid instability of the supersonic boundary layer is convective. The reasons for this discrepancy are analyzed.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 21–29, May–June, 1990.