Nephelometric determination of germanium(IV) witho-phenanthroline and bromopyrogallol red in the presence of triton X-100

The light scattering of germanium(IV) witho-phenanthroline [phen] and bromopyrogallol red [BPR] in the presence of Triton X-100 has been studied. The ternary complex shows a constant light scattering intensity in an acidic medium (0.02 mol/l HCl+0.02 mol/l H₃PO₄). The maximum wavelength was 332 nm. The calibration graph is linear in the range 0.03–10 g/25 ml for Ge(IV). The detection limit is 0.03 g/25 ml. The composition of the ternary complex is GephenBPR = 122. The effects of diverse ions on the determination of Ge(IV) were examined. This simple method with high sensitivity can be successfully applied to the determination of Ge(IV) in coal fly ash, with a relative standard deviation of 2%.     

Thin-layer chromatographic separation of Se(IV), Te(IV), V(V), and Mo(VI) as ternary mixtures and their identification with potassium thiocarbonate (PTC) reagent

Summary Thin-layer chromatography of Se(IV), Te(IV), V(V), and Mo(VI) as ternary mixtures has been described. The separation was effected on a silica gel G layer by employing two different solvent systems: diethyl oxalate-HCl (601v/v) andn-butyl acetate-HCl (400.6v/v). The chromatograms were visualized with 0.1M potassium thiocarbonate (PTC) spray and the limits of identification as determined, lie between 1.27 and 2.04g.

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Zusammenfassung Die Dünnschichtchromatographie ternärer Gemische von Se(IV), Te(IV), V(V) und Mo(VI) wurde beschrieben. Die Trennung wurde auf Schichten von Kieselgel G mit zwei verschiedenen Lösungsmittelsystemen durchgeführt: Diäthyloxalat—Salzsäure (601) und n-Butylacetat—Salzsäure (400,6). Die Chromatogramme wurden mit 0,1-m Kaliumthiocarbonat gesprüht. Die Nachweisgrenze liegt zwischen 1,27 und 2,04g.

     

Spectrophotometric study of the reaction of Co(II) and Ni(II) with nitroso-R-salt and α-nitroso-β-naphthol

The complexes of Co(II) and Ni(II) with nitroso-R-salt are studied by conductometric titration and spectrophotometric methods in buffer solutions of differentpH. The study proved the possible formation of (11), (12) and (13) complexes for Co(II) while Ni(II) forms (11) and (12) complexes (metal:ligand) only. The factors affecting complex formation are established and the formation constants of the complexes are evaluated. The ir spectra of the solid complexes with -nitroso--naphthol revealed that the ligand exhibits the nitrosophenol structure and that the reaction takes place through proton displacement from the OH-group.

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Spektrophotometrische Studie zur Reaktion von Co(II) und Ni(II) mit Nitroso-R-Salz und -Nitroso--naphthol

Zusammenfassung Es wurden die Komplexe von Co(II) und Ni(II) mit Nitroso-R-Salz mittels konduktometrischer und spektrophotometrischer Methoden in Puffer-Lösungen mit verschiedenempH untersucht. Für Co(II) wurden (11)-, (12)- und (13)-Komplexe gefunden, während für Ni(II) lediglich (11)- und (12)-Komplexe (Metall:Ligand) festgestellt werden konnten. Die Faktoren, die die Komplexierung bestimmen, werden diskutiert und die Komplexbildungskonstanten wurden bestimmt. Die IR-Spektren der Komplexe mit -Nitroso--naphthol zeigen, daß der Ligand in der Nitrosophenol-Form vorliegt und daß die Reaktion über eine Protonenverschiebung von der OH-Gruppe verläuft.

     

Zur colorimetrischen Bestimmung von Cer(IV) bei Anwesenheit von Eisen(III) und Lanthan(III) mittels Orthodianisidin

Zusammenfassung Es wird eine neue colorimetrische Methode zur Bestimmung von Cer(IV) unter Anwendung von Orthodianisidin als Reagens vorgeschlagen, mit der Cer(IV)-konzentrationen zwischen 0,86 und 10,39g/ml erfaßt werden können. Unter Anwendung von Phosphorsäure als Maskierungsmittel ermöglicht diese Methode die colorimetrische Bestimmung von Cer(IV) im Beisein von Eisen(III) bis zum Verhältnis Ce^IVFe^III=1800. Desgleichen läßt die Methode die colorimetrische Bestimmung von Cer(IV) bei Anwesenheit von Lanthan(III) bis zum Verhältnis Ce^IVLa^III=150 zu.     

Mixed ligand titanium(IV) complexes. Chlorobis(dithiocarbamato)bis(methylsalicylato)titanium(IV) andbis(dithiocarbamato)bis(methylsalicylato)titanium(IV)

Summary Dichlorobis(methylsalicylato)titanium(IV) reacts with potassium or amine salts of dialkyl or diaryl dithiocarbamates in 11 and 12 molar ratios in anhydrous benzene (room temperature) or in boiling CH₂Cl₂ to yield mixed ligand complexes: (AcOC₆H₄O)₂ Ti(S₂CNR₂)Cl (1) and (AcOC₆H₄O)₂ Ti(S₂CNR₂)₂ (2), R=Et, n-Pr, n-Bu, cyclo-C₄H₈ and cyclo-C₅H₁₀. These compounds are moisture sensitive and highly soluble in polar solvents. Molecular weight measurement in conjunction with i.r.,¹H and¹³C n.m.r. spectral studies suggest coordination number 7 and 8 around titanium(IV) in (1) and (2) respectively.     

Mischligandenderivate des 1:1-Th(IV)—DTPA-Chelates mit Milchsäure,Mandelsäure und o-Hydroxynaphthoesäuren

Potentiometric studies of the mixed ligand derivatives of 11-Th(IV)—DTPA chelate (whereDTPA=diethylene-triamine pentaacetic acid) with certain secondary ligands, such as lactic, mandelic and o-hydroxynaphthoic acids have been carried out. The pH-titrations of the reaction mixtures containing 111 molar ratio of metal ion toDTPA to secondary ligand have shown the formation of 111 ternary complexes at higher pH (8). The equilibrium constants of the resulting mixed complexes have been determined at 30±1°C and =0.1 (KNO₃) and the order of stability in terms of secondary ligands has been found to be o-hydroxy naphthoic acids>mandelic acid>lactic acid.

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Chemistry of hafnium: Complexes of hafnium(IV) with 2-amino-1-cyclopentene-1-dithiocarboxylic acid and its N-alkyl derivatives

Summary The chemistry of bidentate (S,S^–) donor ligands 2-amino-1-cyclopentene-1-dithiocarboxylic acid (HL) and itsN-alkyl derivatives [alkyl = Me (HL¹), Et(HL²) and Bu(HL³)] with hafnium(IV) chloride in 11, 12, 12, 13 and 14 molar ratios is described. These complexes were characterized by elemental analysis, u.V., i.r. and n.m.r. spectral studies. Disulphur chelation with coordination numbers 5, 6, 7 and 8 was observed in all the metal chelates.     

Reactivity of oxalates of La(III), Ba(II) and Cu(II) in ternary mixtures

Composites of cuprates of La(III) and Ba(II) were obtained by decomposing mixtures of oxalates of La(III), Ba(II) and Cu(II) prepared in 111 and 123 mol proportions respectively and sintering the oxide products at 1173 K. Reactions studied by TG, DTA and XRD techniques revealed the following features: (i) Decomposition of oxalates of La(III) and Ba(II) is drastically affected in mixtures. Decomposition temperature of organic part in the former (111) is shifted by 100 K while that of BaCO₃ in the case of latter (123) is shifted by 400 K towards lower temperature side. (ii) All exothermic peaks on DTA traces of both the mixtures are allotted to the decomposition of oxalates to Cu₂O, La₂O₂CO₃ and BaCO₃ phases while endothermic peaks around 863 and 1083 K are assigned for BaCuO₂ and La₂CuO₄ phases respectively in the case of former (111) and endothermic peaks at about 1068, 1136 and 1213 K are correlated with BaCuO₂, a composite of La₂O₃, La₂CuO₄ and La_0.5Ba_0.5CuO_3– (0.5) phases and LaBa₂Cu₃O_7– (0) phase respectively in the case of latter (123) and (iii) Lines of all cuprate compounds appear in XRD patterns of those samples preheated at temperatures 873 K. The following reaction is proposed in the case of 123 mixture: Authors are deeply thankful to the Authorities of Department of Atomic Energy (DAE), Goverment of India, for providing the funds for research project and to Professor A. V. Phadke, Department of Geology, University of Poona, for the valuable discussion.     

Studies on plutonium(IV) hydroxosuccinate

The precipitation behaviour of basic plutonium(IV) compounds from dilute nitric acid medium with aliphatic dicarboxylic acids has been investigated. Unlike plutonium(IV) oxalate, which is precipitated in acid medium (1–4M), the higher dicarboxylates precipitate in 0.9–2.5 pH range and their elemental analysis indicate Pu/dicarboxylate ratio of 11. The mode of formation, composition, solubility and thermal degradation behaviour for plutonium(IV) hydroxosuccinate has been studied. The hydroxy group determination by kinetic titration using fluoride complexing revealed that the compound has a Pu:OH ratio of 11 and determination of bridging oxygen group gave a Pu:O ratio of 10.5 suggest its formation as hydroxysuccinate having an oxobridged formula.     

Studies on mixed ligand complexes involving ligands of biological importance [Ni(II), Zn(II) or Cd(II)-1,10-phenanthroline — or 2,2′-bipyridyl-histidine]

The formation of mixed ligand complexes of the title metal ions with 1,10-phenanthroline (Phen) or 2,2-bipyridyl (Bipy) in presence of histidine (His) has been studied pH-metrically. The stepwise formation of 111 mixed ligand complexes has been inferred from the potentiometric titration curves. Initially, a 11 metal—Phen or—Bipy complex is formed in the lower buffer region and then the addition ofHis takes place resulting in 111 ternary complex formation. The formation constants (K _MAL ) of the resulting mixed ligand complexes have been calculated at 30±1°C (=0.1 KNO₃) and the values have been found to be higher than the formation constants of 12 and lower than those of 11 metal—His complexes. The order of stability in terms of metal ions follows the order, Ni(II)>Zn(II)>Cd(II).With 2 Figures     

Kinetics of ion-exchange of transition metals on tin(IV) arseno-silicate cation exchanger

Exchange kinetics of some transition metal ions on tin(IV) arsenosilicate has been studied at various temperatures under particle diffusion controlled conditions. Various useful kinetic parameters such as self-diffusion coefficient (D_o), energy of activation (E_a) and entropy of activation (S^*) have been calculated and compared with other similar materials.

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(IV) . , (D_O), (E_a) (S^*), .

     

Die Reaktion von Ce(III), Th(IV) und U(VI) mit Chinizaringrün und seinem nichtsulfonierten Grundkörper

The reaction of 1,4-(2-sulpho-4-methylanilino)anthraquinone (quinizarin green,QG) and its non-sulphonated derivative (NSQG) with Ce(III), Th(IV), and U(VI) was investigated. Spectrophotometric and conductometric studies were carried out to investigate the stoichiometry of the complexes formed. The studies revealed the formation of 11 and 12 (ML) complexes. The apparent stability constants of the different complexes were determined. The structure of the ligand in the solid chelates was studied by IR spectrophotometry which showed that the chelate formation takes place through the oxygen of the C=O group and the -imino nitrogen.

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Kinetics of the homogeneous oxidation of hydrogen by platinum(II) and platinum(IV) chloro complexes in aqueous solution

The kinetics of the homogeneous oxidation of hydrogen in the Pt(II)–Pt(IV)–Cl^––H₂O system has been studied for the first time in conditions permitting to avoid the formation of Pt-black. It is shown that platinum (II) [Pt(II)Cl_i(H₂O)_4-i, where i=1, 2, 2], is active in the reaction, whereas the PtCl ₄ ^2– complex and platinum(IV) do not react with hydrogen.

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, Pt-, H₂ Pt^II–Pt^IV–Cl^––H₂O. (II) (Pt^IICl_i(H₂O)_4-i, i=1, 2, 3); PtCl ₄ ^2– (IV) .

     

Determination ofFe 2+ content of NiZnCo iron-excess ferrites by thermogravimetry

Experimental results are reported on the determination by thermogravimetry of the iron(II) content of the NiZnCo ferrite with the molar ratio Fe₂O₃NiOZnOCoO=59.019.520.51.0.     

Anion-exchange TLC of rhodium(III) and iridium(III,IV) on DEAE-cellulose or ECTEOLA-cellulose

Summary The TLC behaviour and separation of Rh(III), Ir(III) and Ir(IV) has been investigated in the two systems composed of DEAE-cellulose or ECTEOLA-cellulose using 3 M or 5 M HCl containing NaClO₃ as solvent. These systems, especially in combination with a sample treatment with LiCl, HCl and H₂O₂ solutions, allow the clean-cut separations of Rh(III) from Ir(III) as well as Ir(IV), coexisting in an extremely wide range of amounts and ratios (RhIr=1500 to 2001). A brief discussion on the characteristic adsorption behaviour of Rh(III), dependent on the previous history of the sample solutions, is also included.

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Anionenaustausch-Dünnschicht-Chromatographie von Rhodium(III) und Iridium(III, IV) auf DEAE- oder ECTEOLA-Cellulose

Zusammenfassung Zur dünnschicht-chromatographischen Trennung von Rh und Ir wurden DEAE- bzw. ECTEOLA-Cellulose mit 3 M bzw. 5 M NaClO₃-haltiger Salzsäure als Lösungsmittel benutzt. Besonders in Verbindung mit einer Probevorbehandlung mit LiCl, HCl und H₂O₂ konnten mit diesen Systemen scharfe Trennungen von Rh(III), Ir(III) und Ir(IV) in einem weiten Konzentrationsbereich erzielt werden (RhIr=1500 bis 2001). Das Adsorptionsverhalten des Rh(III) in Abhängigkeit von der Vorbehandlung der Probelösung wird diskutiert.

     

Mixed ligand derivatives of Th(IV)-EDTA,-CDTA or-DTPA chelate with glycollic and malic acids

The interaction of 11 Th(IV)-EDTA,-CDTA or-DTPA chelate with glycollic and malic acids has been investigated potentiometrically and the formation of 111 mixed ligand chelates inferred from the potentiometric curves. The hydrolysis and dimerization constants of the binary chelates and the equilibrium constants of the ternary derivatives have been evaluated at 30±1° and 35±1°C and also the thermodynamic functions, viz. F ⁰, H and S.With 3 Figures     

Titrimetrische Mikrobestimmung von Steroid-16α,17α-Diolen mit Blei(IV)-acetat

Zusammenfassung Eine neue maßanalytische Methode zur Bestimmung von 16, 17-Dihydroxysteroiden wurde beschrieben. Die Titration wird mit Blei(IV)-acetat-Maßlösungen (0,01-n bzw. 0,001-n) in einer Lösung von Kaliumacetat in 0,25-n Essigsäure durchgeführt. Die Endpunktermittlung erfolgt potentiometrisch. Das Äquivalentverhältnis beträgt 12. Die beschriebene Methode ist zur Bestimmung von Zehntelprozenten 16,17-Dihydroxysteroid als Verunreinigung in deren Acetoniden geeignet.

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Micro-titration of 16,17-Dihydroxy-steroids with standard lead tetraacetate solution

Summary A new volumetric method is described for the determination of 16,17-dihydroxy steroids. The titration is carried out using standard lead tetraacetate solution as the titrant (0.01N and 0.001N, resp.), while the solvent for the titration is the solution of potassium acetate in acetic acid (0.25N). The end point i s determined potentiometrically. The equivalent ratio is 1 2. The described method enables the determination of 0.1% of 16,17-dihydroxy steroid impurities in their acetonide derivatives.

     

Synthesis and spectroscopic studies on (4,5-dimethyl-3-pyrazolyl) aldazine nickel(II) complexes

Summary (4,5-Dimethyl-3-pyrazolyl)aldazine, L, reacts with nickel(II) salts to form 11 and 12 complexes. The 11 binuclear systems involve two ligands bridging two nickels, in which L behaves as a tetradentate ligand, and the nickel(II) complexes have pseudo-octahedral stereo-chemistry. Some of the 11 and 12 complexes contain coordinated H₂O and bridging OH. Structures of these complexes are proposed on the basis of elemental analyses, conductivity, spectral data (u.v.-vis. and i.r.) and magnetic susceptibilities.     

Cerium (IV) exchange in mordenite

X-Ray diffraction analysis, surface acidity (Hammett method), H₂O and CO₂ adsorption of cerium(IV) exchanged H-mordenite are reported.

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- , ( ) H₂O CO₂ H-, Ce(IV).

     

Copper(II)-disulphide interaction: a spectroscopic and electrochemical study of the interaction of copper(II) with an imidazole-containing disulphide

Summary The interaction of copper(II) salts with the imidazole-containing disulphide 5-(1,2,5-dithiazaepan-5-ylmethylene)-4-methyl-2-ethyl imidazole (MAMI) in MeOH have been investigated. The 11 Cu(ClO₄)₂MAMI system exhibited a single ligand field band at ca. 12200cm^-1, an intense shoulder at ca. 31500 cm^-1 and a less intense split feature at 24400 and 25300cm^-1 assignable to S() Cu^II and S() Cu^II charge transfer (CT) transitions, respectively. The e.p.r. parameters suggested the presence of a CuN₂SO chromophore, however; the 11 Cu(NO₃)₂MAMI system did not exhibit a S Cu^II CT band and the g value was comparatively high. An electrochemical study of the 11 Cu(ClO₄)₂MAMI system in MeOH revealed that the copper-disulphide interaction, though weaker, would confer a high redox potential as well as reversibility, similar to the copper-thioether interaction.