Reactions of 2-pyrimidinyl phosphites with proton-containing nucleophilic reagents

Conclusions The reaction of 4,6-dimethyl-2-pyrimidinyl phosphites with proton-containing nucieophilic reagents is due to the anhydride nature of the C_pry-O-P bond and proceeds with the formation of 4,6-dimethyl-1,2-dihydro-2-pyrimidone and the corresponding P(III) derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 159–162, January, 1986.     

Synthesis and structure investigation of the Pb3V(PO4)3 eulytite

Lead vanadium phosphate Pb₃V(PO₄)₃ was synthesized by solid state reaction and characterized by X-ray single crystal and powder diffraction, electron microscopy, and magnetic susceptibility measurements. The crystal structure model of Pb₃V(PO₄)₃ was refined using X-ray single crystal data (a=10.127(1)Å, S.G. Z=4). The compound has an eulytite-like structure and its average structure model may be presented as a three-dimensional network formed by strongly distorted mixed (Pb/V^III) metal-oxygen octahedra connected by edge sharing and forming corrugated chains. The octahedra are additionally linked by tetrahedral phosphate groups via corner sharing. Lead and vanadium atoms randomly occupy two close positions in the octahedra. The electron microscopy study revealed the presence of a rhombohedral superstructure with and indicating ordering in the structure. The same type of superstructure was found by us for two another lead-containing eulytite Pb₃Fe(PO₄)₃ where Fe⁺³ has an ionic radius close to that of V⁺³. Magnetic susceptibility measurements revealed Curie-Weiss behavior for the Pb₃V(PO₄)₃ compound.     

Reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine with bis(bromomethyl)phosphinic acid

The reaction of the Na salts of 2-amino-6-methyl-4-hydroxypyrimidine and bis(bromomethyl)phosphinic acid gave 3,5-dioxo-1,2,3,4,5,8-hexahydro-7-methyl-1,8-diaza-4a-azonia-3-phosphanaphthalene-3-olate, whose structure was determined by X-ray diffraction study. The molecule has a bipolar structure, in which a positive charge is delocalized on the guanidine fragment and a negative charge is on the phosphinic acid fragment.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1125–1128, June, 1995.     

Anodic oxide-film of the Co—Sn—O composition

Properties and electrocatalytic activity of thin-film (∼2 μm) oxide coatings on aTi support are considered by the example of the anodic chlorine evolution reaction. The coatings are obtained by thermally decomposing Co and Sn chloride solutions of different compositions on a Ti plate. The Co and Sn oxides are present in all studied compositions as individual phases and form no compounds or solid solutions. The oxide coating containing 70 at. % Co and 30 at. % Sn reveals a maximum electrocatalytic activity. The existence of the optimum composition is attributed to a favorable effect tin dioxide has on the formation of a transition layer between the Ti support and oxide coating. Tin dioxide hampers the Ti diffusion in the main coating and its subsequent oxidation, thus diminishing the negative impact titanium oxides have on the coating     

Influence of solvents on the molecular and crystal structure of the complex of 1,3-diallyl-5-[3-(diphenylphosphino)propyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione with palladium(II) dichloride

X-ray diffraction study demonstrated that the molecular and crystal structures of the complexes of 1,3-diallyl-5-[3-(diphenylphosphino)propyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (1) with PdCl₂ are determined to a large degree by intra- and intermolecular short contacts between different-polarity groups of the complex molecules. The strength and the existence of the complexes may be affected by the solvents from which the crystals are grown. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1199–1204, July, 2000.     

Novel macrocyclic uracil derivatives: Structure in solid and solution

Isomeric pyrimidinophanes containing uracil moieties and nitrogen atoms in bridges have been synthesized and characterized by a variety of methods both in solid and in solution. Unambiguous assignment of mutual arrangement of C(4)_pyrO groups at different pyrimidine rings in isomers is made by X-ray diffraction. In solutions the arrangement of C(4)_pyrO groups of the isomeric pyrimidinophanes results in different dipole moments. Based on dipole moments simulations mutual orientation of uracil units in isomers is analysed. UV-data are discussed in terms of hypo- or hyperchromic effect.     

On the optimization of a CAPM portfolio using lower partial moments as measure of risk and using the possibility of safeguarding its loss

Using a portfolio built from bonds (investment without volatility) and shares (investment with volatility) corresponding to the CAPM we calculate the possible loss of this portfolio. The loss is measured by a so-called lower partial moment of the rate of return of the portfolio. Using this loss, we optimize the composition of the portfolio with respect to this loss. Also we investigate the optimization of the portfolio when the loss can be underwritten by an insurance. Concerning the premium of this insurance contract, we show that when the premium is defined inadequate, e.g. proportional to the investment or proportional to the amount of investment in shares, the optimal portfolio consists only of investment in shares. When the premium is defined more suitable, e.g. proportional to the loss, the optimal portfolio is built by an investment in bonds and shares.