Synthesis and structure of di(NON-azoxy)formals and some relatedN-alkyl-N′-alkoxydiazeneN-oxides

A series of di(NON-azoxy)formals and some relatedN-alkyl-N′-alkoxydiazeneN-oxides were prepared by the reaction ofN-nitrosohydroxylamine salts with dihaloalkanes. The dependence of the yield of di(methyl-NON-azoxy)formal on the reaction conditions and the nature of the cation was studied. The structure of di(methyl-NON-azoxy)formal and di(phenyl-NON-azoxy) formal as well as of the coppertert-butylnitrosohydroxylaminate was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1486–1493, August, 1997.     

Synthesis and structure of O-alkyl alkylphosphonoselenoic acids and their salts

Conclusions We have prepared O-alkyl alkylphosphonoselenoic acids by reaction of O-alkyl alkylphosphonites with selenium in the presence of amines or alkali metals followed by acidification. We have shown by¹H and³¹P NMR and IR spectroscopy that these acids and their salts exist in solution in the selenophosphoryl form.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya., No. 2, pp. 437–440, February, 1978.     

Construction of optimum profiles for multipole lenses

A flexible and easy to implement method is proposed for computing the multipole-lens potential and field. It integrates conformal-mapping technology and numerical approaches. A procedure for the sequential optimization of the geometric pole shape that is aimed at improving the lens characteristics is described and demonstrated with examples.     

Total Profiling of an X-Ray Pattern of Pyrolytic Manganese Dioxide

The structure of pyrolytic manganese dioxide is analyzed by the method of total profiling of x-ray polycrystal patterns. Coordinates of atoms, temperature factors, unit cell periods of -MnO₂, and filling coefficients of positions specifying the degree of stoichiometry are refined. It is established that the nonctoichiometry index is equal to 0.06(1).     

Influence of the nature of the filling gas and the radial temperature profile on the density profiles of the plasma components in closed systems

Calculations are carried out for the compositions of the plasmas which are produced in closed cylindrical volumes filled with Xe, N₂, O₂, and CO₂, with the radial temperature profile T(r) approximated by a step function. The redistribution of the plasma density is shown to be strongly influenced by the magnitude of the temperature drop and the ratio of the volumes of the regions at the two different temperatures.     

Redox-active metal(II) complexes of sterically hindered phenolic ligands: Antibacterial activity and reduction of cytochrome c. Part II. Metal(II) complexes of o-diphenol derivatives of thioglycolic acid

The synthesis and physico-chemical characterization of Fe(II) and Mn(II) complexes of 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (HL^I) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfinyl]acetic acid (HL^II) were carried out. The investigation of the molecular and electronic structure of Cu(II), Ni(II), Zn(II), Fe(II) and Mn(II) complexes has been performed within the density functional theory (DFT) framework. The computed properties were compared to the experimental ones, and molecular structures of the compounds were proposed based on the array of spectral data and quantum chemical calculations. Antibacterial activity of the Fe(II) and Mn(II) complexes was evaluated in comparison with Cu(II), Co(II), Ni(II) and Zn(II) complexes and three standard antibiotics; it was found to follow the order: (1) Сu(L^I)₂ > Mn(L^I)₂ > HL^I > Ni(L^I)₂ > Zn(L^I)₂ > Fe(L^I)₂ > Co(H₂O)₂L^I; (2) Cu(L^II)₂ > Сo(L^II)₂ > Ni(L^II)₂ > Mn(H₂O)₂(L^II)₂ > Fe(L^II)₂ > HL^II > Zn(L^II)₂; their reducing ability (determined electrochemically) followed the same order. Spectrophotometric investigation was carried out in order to estimate the rate of the reduction of bovine heart сytochrome c with the ligands and their metal(II) complexes. The complexes Сu(L^I)₂, Mn(L^I)₂ and Co(L^II)₂ with the high reducing ability were found to be characterized by the highest rates of Cyt с reduction. NADPH:cytochrome P450-reductase had no substantial effect on the rate of сytochrome c reduction with HL^I and HL^II ligands.