Wyniki wyszukiwania - Biblioteka Nauki

1

Complexes of iron(III) salen and saloph Schiff bases bridges by dicarboxylic acids

100%

Kopel P. , Sindelar Z. , Biler M. , Klicka R.

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1998

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tom Vol. 72, nr 9

2060-2066

EN

Six dinuclear Fe(III) complexes involving tetradentate Schiff bases N,N'-bis(salicylidene)ethylenediamine (salenH2) or bis(salicylidene)o-phenylenediamine (salophH2) with 2,6-pyridinedicarboxylic acid (2,6-dicarpyH2), thiodiglycolic acid (tdgaH2) or 3,3'-thiodipropionic acid (3,3'-tdpaH2) have been synthesized and characterized by elemental analysis, IR spectroscopy and conductivity measuremenys. The magnetic behavioral of all complexes has been studied between 77-298 K. The dicarboxylic acids form bridges between paramagmetic centers and weak antiferromagnetic intramolecular exchanges were found. Thus, the complexes can be characterized as high spin distorted octahedral iron(III), except for [{Fe(saloph)}2(2,6-dicarpy)], where S1 = S2 = 3/2 spin-exchange model complies best with experimental data and the iron(III) has probably aquare-pyramidal coordination mode. The HDW S1 = S2 = 5/2 spin-exchange model with (H = -2S1S2) was applied in the case of the other complexes. The antiferromagnetic coupling parameters J vary in the range of -1.06 to -5.87 cm(-1).

2

Equilibrium and rate of iron(III) extraction from chloride solutions by individual hydrophobic extractants and their mixtures

88%

Staszak K. , Cierpiszewski R. , Prochaska K.

Polish Journal of Chemical Technology

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2011

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tom 13

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nr 1

1-5

EN

The main goal of this work was to study and compare the rate of iron(III) extraction from chloride solutions by commercial extractants: Alamine 336, TOPO and LIX 54 and their mixtures. Using the interfacial tension data, obtained for mixed systems, the values of surface mole fraction and molecular interaction parameter of extractants were estimated. Determination of the extraction rates was performed by using the Lewis-type stirred transfer cell. It was found that the extraction efficiency of extractants are changed in the following order: Alamine 336>TOPO>β-diketone. The addition of a chelating extractant to the system decreases the extraction efficiency, for example the addition of β-diketone to TOPO decreases the extraction efficiency by about 50%.

3

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions

88%

Marszałkowska B. , Regel-Rosocka M. , Nowak Ł. , Wiśniewski M.

Polish Journal of Chemical Technology

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2010

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tom 12

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nr 4

1-5

EN

Extraction of zinc(II) and iron(III) from hydrochloric acid solutions using quaternary phosphonium salts, Cyphos® IL 101, Cyphos® IL 104, Cyphos® IL109 and Cyphos® IL 111 in mixtures with toluene, was studied. Trihexyl(tetradecyl)phosphonium chloride (Cyphos® IL 101) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos® IL 104) showed the best zinc(II) and iron(III) extraction abilities. After three stages of zinc(II) extraction with Cyphos® IL 101 and Cyphos® IL 104 the efficiencies were 100 and 93.6%, respectively. Total iron(III) transport to the organic phase was achieved after two separation stages and amounted to 82.1 and 100% for Cyphos® IL 101 and Cyphos® IL 104, respectively. Zinc(II) and iron(III) could be effectively stripped from the loaded organic phases with 0.5 mol dm-3 sulfuric acid. The more hydrophobic the character of the anion type of phosphonium salts, the lower the efficiency of extraction.

4

Synthesis, spectral, magnetic and X-ray powder diffraction structural characterization of [Fe(NCS)3(OPPh3)3]

63%

Ondrejkovicova I. , Jorik V. , Mroziński J.

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1998

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tom Vol. 72, nr 8

1890-1896

EN

The autocatalytic oxidation of PPh3 with dioxygen in the systems containing some iron compound and NCS(-) anions in acetonitrile leads to the formation of the complexes [Fe(NCS)3(OPPh3)3], where OPPh3 is triphenylphosphine ixide. The complex is also formed by direct interaction of Fe(NCS)3 with )PPh3. This high-spin iron(III) complex acts as oa oxidation catalyst of PPh3. On the basis of elemental analysis, spectral data and X-ray powder diffraction have been proved that the samples of the complex have not only the same composition but possess the same crystal strycture irrespective of the preparation method.

5

Attempt to evaluate the interactions between sodium silicates of different moduli and selected salts of metals(III)

51%

Koźlak W.

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2007

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tom Vol. 14, nr 7

733-745

EN

Using the turbidimetric method, based on the formation of water soluble, colloidal silicate, systems containing technical sodium water glasses of different moduli produced in Poland and selected salts of trivalent metals (Cr, Fe, Al, in and Sb) were studied. The nature of the course of turbidity curves is related to the type of silicate, !e its silicate modulus and the type of the salt. It was demonstrated that sodium water glasses can be applied to remove Cr3+, Fe3+and Al3+ ions. In the case of indium and antimony salts proposed method is not usable.

PL

Metodą turbidymetryczną, polegającą na otrzymywaniu rozpuszczalnego, koloidalnego krzemianu, badano układy zawierające różnomodułowe techniczne szkła wodne sodowe produkcji krajowej i wybrane sole pierwiastków metali trójwartościowych (Cr, Fe, Al, In i Sb). Charakter przebiegu krzywych zmętnienia związany jest z rodzajem krzemianu, tj. jego modułem krzemianowym oraz rodzajem zastosowanej soli. Wykazano, że szkła wodne sodowe można wykorzystać do usuwania jonów Cr3+, Fe3+ i A13+ z mediów. W przypadku soli indu i antymonu proponowana metoda ma znikome zastosowanie.