Synthesis and Investigation of Indium Dodecatungstosilicate

Indium dodecatungstosilicate of the composition [In(OH)⋅5H₂O]₂ [SiW₁₂O₄₀]⋅H₂O is synthesized and studied by means of IR spectroscopy, thermogravimetry, and X-ray phase analysis. The crystals of this compound are triclinic, space group P1, a 13.079(3), b 13.795(3), c 13.967(3) Å, α 90.08(3)°, β 103.76(3)°, ψ107.76(3)°, Z 2, and π_calc 4.900 g cm⁻³.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 1, 2005, pp. 21–23.Original Russian Text Copyright © 2005 by Kaziev, Dutov, Quinones, Ita, Sychkin.     

Deposition of copper coatings in a magnetron with liquid target

Copper coatings were deposited on monocrystalline Si substrates using a magnetron discharge with a liquid cathode in the metal vapour plasma. During the deposition, the bias voltage in the range from 0 V to–400 V was applied to the substrate. The prepared films were investigated by a scanning electron microscope, and their adhesive properties were studied using a scratch tester. It was demonstrated that the adhesion of the deposited films strongly depends on the bias voltage and varies in a wide range.

     

Synthesis and study of ammonium hexamolybdooxalatovanadate

Ammonium hexamolybdooxalatovanadate of the composition (NH₄)₃[V(C₂O₄)Mo₆O₁₈(OH)₆] · 3H₂O (I) has been synthesized and studied by mass spectroscopy, IR spectroscopy, thermogravimetry, and X_ray powder diffraction. Crystals of I are monoclinic with the unit cell parameters a = 11.9737 Å, b = 18.6533 Å, c = 11.2178 Å, β = 121.021°, V = 3162. 95 ų, M = 1214.01 g/mol, ρ_calcd = 1.91 g/cm³, and Z = 3.     

Synthesis and crystal structure of sodium isopolyvanadate [Na2(H2O)8]2H2[V10O28] · 4H2O

The sodium hydrogen oxovanadate [Na₂(H₂O)₈] ₂H₂[V₁₀O₂₈] · 4H₂O was synthesized and studied by TGA, X-ray diffraction, and NMR and IR spectroscopy. The crystals are triclinic, space group P $ \bar 1 $ \bar 1 , a = 8.545(7) ?, b = 10.827(2) ?, c = 11.627(2) ?, α = 105.48(3)°, β = 99.38(3)°, γ = 101.29(3)°, V = 989.9(3) ?³, ρ(calcd) = 2,381 g/cm³, Z= 1.     

Synthesis and study of ammonium hexamolybdobismuthate(III)

Ammonium hexamolybdobismuthate(III) of composition (NH₄)₃[BiMo₆O₁₈(OH)₆] · 7H₂O (I) was synthesized and studied by mass spectrometry, X-ray diffraction, IR spectroscopy, and thermogravimetry. The compound is monoclinic: a = 10.438 Å, b = 7.909 Å, c = 18.127 Å, β = 96.59°, V = 1486.76 ų, ρ_calc = 3.32 g/cm³, Z = 2.     

Controlled free-radical azeotropic copolymerization of styrene and n-butyl acrylate in the presence of tert-butyl dithiobenzoate

The free-radical azeotropic bulk copolymerization of styrene and n-butyl acrylate at 90°C mediated by tert-butyl dithiobenzoate and copoly(strene—n-butyl acrylate) dithiobenzoate as reversible chain-transfer agents has been studied. It has been shown that low-and high-molecular mass chain-transfer agents allow one to efficiently control the molecular-mass characteristics of the copolymers. For all studied systems, the molecular mass linearly increases with conversion, and the copolymers are characterized by low polydispersity indexes. When polystyryl dithiobenzoate and poly(butyl acrylate) dithiobenzoate are used as polymer reversible chain-transfer agents in the azeotropic copolymerization of styrene and n-butyl acrylate, the diblock copolymers with the controlled block lengths are prepared. As evidenced by ESR studies, radical intermediates are formed in the course of the azeotropic copolymerization of styrene and n-butyl acrylate mediated by tert-butyl dithiobenzoate and the copolymer reversible chain-transfer agent; the kinetics of formation of these intermediates has been investigated. It has been demonstrated that the rate of the azeotropic copolymerization mediated by low-and high-molecular-mass reversible chain-transfer agents decreases with an increase in their concentration. The possible causes of this phenomenon are discussed.     

Development of protective metal coatings on aluminum by magnetron sputtering

Depositions of copper and titanium coatings on aluminum foils and polished aluminum plates for thier protection against corrosion in alkaline media were performed. The coatings were deposited in three different types of magnetron sputtering systems: a direct current (DC) magnetron discharge, a high current impulse magnetron discharge, and a DC magnetron discharge with melted cathode. Only aluminum foils coated with copper films obtained by combined ion-plasma technology, which included preliminarily sputtering of the aluminum surface with an ion beam, deposition of a dense interlayer in the DC magnetron discharge with ion assistance of initial stage of deposition, and deposition of additional layer in the magnetron discharge with melted cathode, were resistant against 30 wt % NaOH solution.     

X-ray diffraction study of ammonium octamolybdate

Ammonium isopolymolybdate (NH₄)₄[Mo₈O₂₆]·4H₂O was prepared for the first time and studied by X-ray diffraction analysis.