Reaction of H2PtCl6 with 18-crown-6 and dibenzo-18-crown-6 in 1,2-dichloroethane and acetonitrile

Compounds of the compositions [2(18-crown-6)6(H₂O)2(C₂H₄Cl₂){Pt²⁺(C₂H₄)}(Pt₂Cl₁₀)^2–], [4(18-crown-6)2(OH₃)⁺2(OH₂)2(NH₃)(Pt₂Cl₁₀)^2–], [(dibenzo-18-crown-6)6(H₂O){Pt²⁺(C₂H₄)}(Pt₂Cl₁₀)^2–], and [4(dibenzo-18-crown-6)2(OH₃)⁺2(OH₂)2(NH₃)Pt₂Cl₁₀)^2–] were prepared by reactions of H₂PtCl₆ with 18-crown-6 and dibenzo-18-crown-6.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1593–1599.Original Russian Text Copyright © 2004 by Guseva, Busygina, Khasanshin, Polovnyak, Yarkova, Yusupov.This revised version was published online in April 2005 with a corrected cover date.     

Electronic structure of C60 films

A complete set of fundamental optical functions of fullerite (C₆₀) films in energy ranges of 2.5–5.0 and 4.0–9.0 eV is calculated using the known spectra of the imaginary and real parts of the dielectric constant. An integrated spectrum of the dielectric constant is decomposed into elementary components. Three basic parameters of each component (the maximum and halfwidth energies and oscillator strength) are determined. Based on the known theoretical calculations of fullerite zones, a scheme of the nature of these components of the dielectric constant is suggested. Udmurt State University, 71, Krasnogeroiskaya Str., Izhevsk, 426034, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 227–232, March–April, 1999.     

Oxidation of bridging groups by carboxylate coordinated ligands in palladium clusters

Thermolysis of tetranuclear palladium clusters Pd₄(-Q)₄ Pd₄(-Q)₄(-O₂CR)₄ (Q=CPh₂ or CO;R=Me, CMe₃, Ph, CH₂Cl or CF₃) has been found to involve innersphere oxidation of carbene or carbonyl ligands during which an oxygen atom transfer occurs from the carboxylate group to the carbene or carbonyl ligand. The thermolysis of the carbonyl clusters gives rise to the products of CO₂ insertion into the C–H bond of benzene or toluene used as solvents forming benzoic acid from benzene and a mixture of phenylacetic and toluic acids from toluene. The reaction of [Pd(OAc)₂(PPh₃)]₂ with HCO₂H includes the transfer of an O atom from formate ligand to the P atom and cleavage of the P-Ph bond accompanied by transfer of the Ph group from PPh₃ ligand to the palladium atom. The structure of the complex formed, [Pd(-O₂PPh₂)(C₆H₅)(PPh₃)]₂, has been resolved by X-ray analysis.     

Complex Formation of Potassium Hexachloroplatinate with 18-Crown-6 and Dibenzo-18-Crown-6 in Acetonitrile

The products of the reactions between potassium hexachloroplatinate {K₂PtCl₆} and 18-crown-6 or dibenzo-18-crown-6 in acetonitrile were studied. Pure crystalline compounds [2K·2(18-crown-6)· 2CH₃CN]²⁺·[PtCl₆]^2-·2H₂O, [2K·dibenzo-18-crown-6·CH₃CN]^{2 +}·[PtCl₆]^{2 -}, and [2K·dibenzo-18-crown-6·CH₃CN]^{2 +}·[Pt₂Cl₁₀]^{2 -} were obtained. Physicochemical properties of these compounds were studied, and their near- and far-IR IR spectra and thermogravimetric curves were considered. The composition of the complexes is determined by metal:ligand molar ratio and crown ether nature. It was found that acetonitrile is coordinated via the nitrogen atom.     

Soft template synthesis of (2,8-dithio-3,7-diaza-5-oxanonandithioamide-1,9) nickel(II) and (2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8)nickel(II) using a nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix

Complexing processes leading under specific conditions to nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix systems in contact with aqueous-alkaline solutions (pH12) containing dithiooxamide and formaldehyde or glyoxal, have been studied. It has been shown that template synthesis of macrocyclic co-ordination compounds, (2,8-dithio-3,7-diaza-5-oxanonandithioamide-1,9)nickel(II) and (2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8)nickel(II), occurs. Dithiooxamide, formaldehyde and glyoxal act as ligand synthons in this process.     

Electrochemical amination. Ti(IV)/Ti(III) mediator system in aqueous solutions of sulfuric acid

As a result of polarographic and spectrophotometric studies, and mathematical modeling, the dependence of electrochemical properties of the Ti(IV)/Ti(III) pair on the composition of the Ti(IV) complexes is established in sulfuric acid solutions. It is found that Ti(IV) in 1–17 M H₂SO₄ at the metal ion concentrations used in the process of amination of aromatic compounds can exist in the form of twelve basic complex forms, of which seven, including the binuclear and two tetranuclear ones, are observed for the first time. Ten forms are electrochemically active. An increase in the overall amount of reversibly reducing cationic mononuclear hydrosulfate complexes of Ti(IV) among these at a growing H₂SO₄ concentration results in an increase in the redox potential of the Ti(IV)/Ti(III) mediator system and therefore in an increase in the yield of the electrochemical amination products.     

Extraction of indium(III) from sulfate solutions with organophosphorus acids

Extraction of indium(III) from sulfuric acid solutions with di-2-ethylhexyl hydrogen phosphate and isododecylphosphethanic and diisooctylphosphinic acids was studied. The effect of H₂SO₄ and In(III) concentrations in the aqueous phase, type and concentration of the extractant in the organic phase, temperature, and time of phase contact on the extraction of In(III) and impurity metal ions was considered. The In(III) extraction constants were estimated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1625–1629.Original Russian Text Copyright © 2004 by Travkin, Kubasov, Glubokov, Busygina, Kazanbaev, Kozlov.     

Examination of the disinfecting properties of calcium peroxide and its suitability for improving hydrodynamic characteristics of surface water bodies

The fundamental possibility of using solid peroxides of alkaline-earth metals for water disinfection purposes was explored. The maximum peroxide concentration in solution is achieved with addition of a mixture of boric and phosphoric acids. Water treatment with calcium peroxide leads to stable dissolved oxygen levels and improves some hydrochemical characteristics of surface water bodies.