Hydrolytic copolycondensation of ethyl silicate with copper salts under heterogeneous conditions

Hydrolytic copolycondensation of ethyl silicate with copper salts in the presence of a base catalyst (NH₄OH) without organic solvent was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11, 2004, pp. 1909–1911.Original Russian Text Copyright © 2004 by Sviderskii, Voronkov, S. Klimenko, Khalkova, V. Klimenko.     

Synthesis and Characterization of Zn(II) and Cd(II) Complexes with Bisdithiophosphonates

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiodiphosphetane-2,4-disulfide (Lawessons reagent) reacts with stoichiometric equivalent of alkane diols HO(CH₂)_nOH (n=2, 3, and 5) to form bisdithiophosphonic acid. The obtained crude bisdithiophosphonic acids are treated with dry NH₃ to give ammonium salts of bisdithiophosphonic acids. Ammonium salts of bisdithiophosphonic acids react with ZnSO₄ in water and Cd(Ac)₂ in ethanol to form new bisdithiophosphonate complexes of Zn(II) and Cd(II). The zinc and cadmium complexes of these tetradentate ligands are isolated in high yields. Ammonium salts of bisdithiophosphonic acids and their Zn(II) and Cd(II) complexes are characterized by elemental analyses, mass spectra (ESI), IR and NMR spectroscopies.__________From Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 338–343.Original English Text Copyright © 2005 by Karakus, Yilmaz, Bulak.This text was submitted by the authors in English.     

Interaction of chelates with macrocyclic ligands. Porphyrins and Hg(II) chelate salts

The complex formation of different porphyrins (5,10,15,20-tetraphenylporphine (I), N-methyl-5,10,15,20-tetraphenylporphine (II), 2,3,7,8,12,13,17,18-octaphenyltetraazaporphyrin (III), and tert-butylphthalocyanine (IV)) with mercury(II) valinate (Hg(Val)₂) in DMSO was studied. The rates of reactions of macrocycles I, II, and IV with mercury(II) valinate were found to be higher than those with valinates of other d metals, and the complex formation rates of III with Hg(Val)₂ were comparable with these characteristics for other valinates. Mechanisms for binding of different porphyrins by Hg(II) chelate salts were proposed.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 2, 2005, pp. 93–97. Original Russian Text Copyright © 2005 by Mamardashvili, Berezin.     

Nitration of Some 3-(2-Furyl)-2-propenones with Dinitrogen Tetraoxide

Nitration of 3-(2-furyl)-2-propenones with dinitrogen tetraoxide leads to the corresponding 3-(4-nitro-2-furyl)-2-propenones. If the furyl group contains a substituent in position 5, the nitration occurs at the side chain to afford 3-(5-R-2-furyl)-2-nitro-2-propenones.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 431–436.Original Russian Text Copyright © 2005 by Sitkin, Klimenko.     

3-Alkyl-2-[3(4)-pyridyl]-5-(2-vinyloxyethoxymethyl)-oxazolidines

1-Alkylamino-3-(2-vinyloxyethoxy)-2-propanols react with 3-and 4-pyridinecarbaldehydes to give equimolar mixtures of cis- and trans-3-alkyl-5-(2-vinyloxyethoxymethyl)-2-[3(4)-pyridyl]oxazolidines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 104–108.Original Russian Text Copyright © 2005 by Kukharev, Stankevich, Lobanova, Klimenko, Kukhareva.     

Synthesis and properties of new tetrachlorocobaltate (II) and tetrachloromanganate (II) anion salts with dicationic counterions

New tetrachlorocobaltate (II) and tetrachloromanganate (II) ionic compounds containing various counterdications were synthesized and characterized. These salts are soluble in polar solvents such as methanol and water. Physical properties such as thermal stability, melting point, and magnetic susceptibility of these salts depend on the cation or anion structure. The thermal stability of the phosphinium or imidazolium based salts is higher than that of the pyridinium or triethylaminonium analogues. The melting point of these compounds is following the order of triphenylphosphinium > pyridinium > imidazolium dications, and symmetrical dicationic salts > unsymmetrical ones. The magnetic susceptibility (χ_MT values) of tetrachloromanganate (II) anions-based salts is higher than that of tetrachlorocobaltate (II) anions-based salts. These dicationic salts exhibit weak antiferromagnetic interactions and have higher magnetic susceptibility than that of the previously reported tetrachloromanganate (II) and tetrachlorocobaltate(II) salts with monocationic counterion.     

Aromatic substitution. The effect of alcoholic solvents on the reaction of phenyltriethyltin with mercury (II) salts

Second-order rate constants are reported for the cleavage of the phenyltin bond of phenyltriethyltin by mercury(II) salts in ethanol. propan-1-ol, propan2-ol and butan-1-ol. It is shown that the reactivity order for the mercury(II) salts is HgI₃^? << HgI₂ < HgCl₂. Activation parameters are reported, and on the basis of the low values of activation enthalpies the presence of an intermediate π-complex is suggested for the reactions.     

Extraction of Zinc and Copper with Acetylenic Quaternary Ammonium Salts

Extraction of zinc(II) and copper(II) from HCl solutions with solutions of mono- and dialkynyl-substituted quaternary ammonium halides in chloroform and toluene is more efficient than the extraction with saturated quaternary ammonium salts and occurs by different mechanism. The dependences of the metal distribution factors on the HCl concentration have two maxima whose positions (absolute and relative) and relative intensities depend on the particular extractant, metal, and diluent.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 712–718.Original Russian Text Copyright © 2005 by Andreev, Tunina, Remizova.     

Studies on the Interaction of Lead(II) and Uranyl(II) with Methylcysteine and Penicillamine Bioactive Sulfur-Containing Ligands

Quantitative indication of a complex formation comes from the estimation of the stability or formation constants characterizing the equilibria corresponding to the successive addition of ligands. The binary equilibria of metal(II)-methylcysteine and also mixed equilibria metal(II)-methylcysteine-penicillamine are studied using paper electrophoretic technique. The method is based on the migration of a spot of metal ion with the complexones added to a background electrolyte at the pH 8.5. The stability constants of the mixed complexes Pb(II)-methylcysteine-penicillamine and UO₂(II)-methylcysteine-penicillamine are found to be 2.80 ± 0.09 and 3.40 ± 0.07 (logarithm of stability constant values) at a ionic strength of 0.1 M (HClO₄/NaClO₄) and a temperature of 35°C.__________From Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 344–348.Original English Text Copyright © 2005 by Tewari.This text was submitted by the author in English.     

Extraction-polarographic determination of cobalt(II) and nickel(II) as 2,2′-bipyridine complexes in acetonitrile

The tris(2,2′-bipyridine)cobalt(II) complex gives a reversible d.c. wave with E$\text{1}\text{2}$ = ?1.02 V vs. SCE and a sharp differential pulse peak at E_p = ?1.03 V in a salted-out acetonitrile phase. A simple selective method is described for the determination of cobalt(II); down to 0.25 μg of cobalt(II) can be determined in presence of large amounts of Ni, Zn, Cd, Pb, and Cu; iron(III) can be masked with sodium fluoride. The method is applicable to the determination of >0.0l% cobalt in nickel salts and >5 × 10^?5% cobalt in iron salts. Nickel(II) can also be extracted from aqueous solution and determined by differential pulse polarography, even in presence of a 20-fold amount of cobalt(II) by masking with EDTA; >0.01% of nickel in cobalt salts can be determined reproducibly.     

Determination of Barium by Classical and Alternating-Current Polarography

The behavior of barium(II) in 0.1–5.0 M CaCl₂ solutions was studied by classical and alternating-current polarography. The kinetic parameters of barium(II) reduction and the diffusion coefficients were determined. A procedure for the determination of barium in calcium salts was proposed.     

Characteristic features of the synthesis, solubility products, and absorption spectra of basic cobalt(II) acetate, nitrate, and chloride salts

The solubility products of basic cobalt(II) salts Co(OH)_1.80(An)_0.20, where An are NO₃⁻ and CH₃COO⁻, and Co(OH)_1.50(CH₃COO)_0.50 were determined by the method of three variables. The stability of the salts Co(OH)_1.80(An)_0.20 against hydrolysis increases in the series < CH₃COO⁻ < Cl⁻. The absorption maxima of Co²⁺ ions in solutions, β-Co(OH)₂ powders, and the pink Co(OH)_1.50Cl_0.5 salt are located in the frequency regions typical of the octahedral coordination; those of CoOH⁺ ions in solutions and powders of green basic cobalt salts are in the frequency regions typical of the tetrahedral coordination. A model for the formation and interconversion of basic cobalt salts with single-charged anions is proposed.     

Nickel(II) derivatives of N-benzyliminodiacetate(2−) ligands,with and without imidazole: Synthesis,crystal structure and properties

In an attempt to prepare binary and ternary compounds, we have obtained two molecular complexes [Ni(MEBIDA or MOBIDA)(H₂O)₃]·nH₂O (n = 0 or 1) and two iso-type salts [Ni(Him)₆][Ni(MEBIDA or MOBIDA)₂]·4H₂O [MEBIDA = N-(p-methylbenzyl)iminodiacetate(2−) and MOBIDA = N-(p-methoxybenzyl)iminodiacetate(2−) ligands, Him = imidazole]. Our results are discussed with regard to related copper(II) and nickel(II) compounds. The reasons for which these chelating ligands produce nickel(II) salts instead of ternary compounds remain unclear since other iminodiacetate-like ligands give true ternary Ni(II) compounds with imidazole and other N-heterocyclic ligands.     

Synthesis of higher epoxides by the joint catalytic oxidation of aldehydes and olefins

Conclusions The selective catalytic epoxidation of 1-alkenes by molecular oxygen was accomplished in the presence of C₂-C₅ alipahtic aldehydes and catalysts, viz., the salts of Cu(II), Ni(II), Fe(III), or Zr(IV).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2269–2272, October, 1985.     

Study of the concentration and separation of cadmium with microcrystalline phenolphthalein modified by crystal violet

A new method for cadmium separation and concentration with microcrystalline phenolphthalein modified by crystal violet (CV) was developed in the paper. In the presence of potassium iodide (KI) and CV, cadmium are quantitatively absorbed on microcrystalline phenolphthalein in the pH range 1.0-6.0 as the forms of water-insoluble ion-associated complexes (CdI₃⁻)·(CV⁺) and (CdI₄²⁻)·(CV⁺)₂. Effect of different parameters such as phenolphthalein amount, stirring time, the concentration of CV and KI, various salts and metal ions was studied in detail. During the present study, a significant enhancement of the extraction of cadmium was observed. Cd(II) can be completely separated from Zn(II), Fe(II), Co(II), Ni(II), Mn(II), Cr(III) and Al(III) in this microcrystalline system and well concentrated without the interference of these metal ions at high level. The possible reactive mechanism of cadmium concentration has been discussed. Analytical results obtained by this new method were very gratifying.     

Synthesis and Thermal Analysis of 2,2′-bipyridine Divalent Transition Metal Hexachloroplumbates

Several complex salts of the general formula [M(II) (bipy)_x(H₂O)_y]PbCl₆ (where x=2–3, y=0–2 and M=Mn(II), Fe(II), Ni(II), Co(II), Cu(II), Zn(II), Cd(II) and Hg(II)) were synthesized and investigated by DTA, TG and DTG. Some of the decomposition products were identified by IR spectroscopy and other methods. The compounds decompose with the liberation of water (in the case of hydrates), chlorine (sometimes causing chlorination of organic fragments), organic molecules (sometimes chlorinated) and sometimes hydrogen chloride. The residues comprise metal(II) chlorides and PbCl₂. This revised version was published online in August 2006 with corrections to the Cover Date.     

Heteronuclear Complexes of Germanium(IV) and of Some Other 3<Emphasis Type="Italic">d</Emphasis> Metals with Diethylenetriaminepentaacetic Acid

Heteronuclear Ge(IV) complexonates with Co(II), Ni(II), and Zn(II) based on diethylenetri-aminepentaacetic acid (H₅Dtpa) are synthesized for the first time. The composition of the complexes is found from the chemical analysis and thermogravimetry data. The coordination polyhedra of cobalt and nickel are determined by the analysis of the diffuse reflection spectra and effective magnetic moments. Information on the coordination of the polydentate ligand is obtained by the comparative analysis of the IR spectra of the synthesized complexes and previously structurally characterized compounds [Ge(OH)(H₂Dtpa)] · H₂O and [Cu{Ge(OH)(µ-HDtpa)}₂] { 12H₂O.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 572–575.Original Russian Text Copyright © 2005 by Martsinko, Seifullina, Verbetskaya.     

Complexation studies of N,N′-ethylene-bis(salicylideneimine)-cation complexation behavior in dioxane-water mixtures by conductometric studies

The tetradentate-ligand Schiff base derived from salicylaldehyde and 1,2-diaminoethane has been synthesized. The stability constants and thermodynamic values for the complexation between ZnCl₂, Cu(NO₃)₂, and AgNO₃ salts and the ligand in 80% dioxane-water were determined by conductance measurements. The order of the formation constant for complexes of the ligand with Cu(II), Zn(II), and Ag(I) ions was found to be: Ag(I) < Cu(II) < Zn(II). The magnitudes of these ion association constants are related to the nature of the solvation of the cation and the complexed cation. The text was submitted by the authors in English.     

Synthesis and Catalytic Properties of Copper(II) 1-Aryl-5-Benzothiazolylformazanates

New copper(II) benzothiazolylformazane complexes were synthesized and immobilized on AN-18 anion exchanger. The influence of the composition of the coordination core of copper(II) benzthiazolyl-formazanates and temperature on their catalytic properties in decomposition of H₂O₂ and oxidation of Na₂S in aqueous solution was studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 957–961.Original Russian Text Copyright © 2005 by Gorbatenko, Pervova, Lipunova, Maslakova, Lipunov, Sigeikin.     

Preparation of 1‐X‐2, 2‐Difluoroethenylxenon(II) Tetrafluoroborates [CF2=CXXe][BF4]

The new type of alkenylxenon(II) salts [CF₂=CXXe] [BF₄] (X = H, Cl, CF₃) was prepared by reacting the corresponding alkenyldifluoroboranes CF₂=CXBF₂ with XeF₂ in 1, 1, 1, 3, 3‐pentafluoropropane (PFP) at —60 °C. The alkenylxenon(II) salts were characterised by multinuclear NMR spectroscopy. The influence of the substituent X at C‐1 on the stability of alkenylxenon(II) salts is discussed. Additionally the preparation of the potassium alkenyltrifluoroborate salts K [CF₂=CXBF₃] and their transformation into the boranes CF₂=CXBF₂ by fluoride abstraction in PFP is reported.