Reaction between [Ru3(CO)10(μ-dppm)] (dppm = Ph2PCH2PPh2) and Te2(C6H4OEt-4)2: X-ray crystal structure of [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}]

Treatment of [Ru₃(CO)₁₀(-dppm)] (1) with the ditelluride Te₂(C₆H₄OEt-4)₂ in refluxing toluene afforded the new aryltellurol bridged complex [Ru₂(CO)₄(-TeC₆H₄OEt-4)₂ (-dppm)] (2) together with three known complexes [Ru₄(CO)₈(-CO)(₄-Te)₂(-dppm)] (3), [Ru₂(CO)₆{-CH₂PPh(C₆H₄)PPh}] (4), and [Ru₂(CO)₆{-C₆H₄PPh(CH₂)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P2₁/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, = 97.49(2)°, V = 2560.4(8) ų, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C₆H₄PPh(CH₂)PPh which is attached to one Ru by the C₆H₄ group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.     

Numerical study using ADM for the modified regularized long wave equation

The modified regularized long wave (MRLW) equation is solved numerically by Adomian decomposition method (ADM) with some initial conditions. The method leads to high accurate and efficient results. Three polynomial invariant conditions are evaluated to determine the conservation properties of the problem. The convergence of Adomian decomposition method applied to the MRLW equation is proved. Moreover, the interaction of solitons and the development of the Maxwellian initial condition into solitary waves are considered.     

Applications involving oxidation with ethanolic iodine. Rapid potentiometric method for some reductants

Rapid potentiometric method was adopted for the determination of small amounts of hexacyanoferrate(II), thiosulfate, thiocyanate, and ascorbic acid, based on oxidation with ethanolic iodine at different pH values and subsequently titration of iodide with mercury(II) using silver amalgam as indicator electrode. The potential breaks at the vicinity of the endpoints were sharp enough for their accurate detection. The method provides for accurate determination of small amounts of some reductants of analytical importance.     

Hypoelliptic Jacobi–Dunkl Convolution of Distributions

In this paper we give a necessary and sufficient condition in terms of the Jacobi–Dunkl transform in order that a Jacobi–Dunkl convolution of distributions is hypoelliptic.     

Quantization of gauge fields through fibre bundle multiconnectivity

A geometric model for the quantum nature of interaction fields is proposed. We utilize a trivial fibre bundle whose typical fibre has a multiconnectivity characterized by a discrete group Γ. By seeing Γ as a gauge group with global action on each fibre, we show that the corresponding field strength is non-zero only on the future part of the light cone whose vertex is at the interaction point. When the interaction is submitted to the symmetries of a Lie group G, we consider the gauge group G x Γ. The field strength of the gauge having this group includes a term expressing the quantization of the interaction field described by G. This geometric interpretation of quantization makes use of topological arguments similar to those applied to explain the Aharonov-Bohm effect. Two examples show how this interpretation applies to the cases of electromagnetic and gravitational fields.      

Selective flotation-separation and spectrophotometric determination of cadmium using phenanthraquinone monophenythiosemicarbazone.

A simple, selective and sensitive procedure is described for the preconcentration by flotation followed by spectrophotometric determination of trace amounts of Cd(II). Cadmium forms an intense red 1:2 complex with phenanthraquinone monophenylthiosemicarbazone (PPT) at pH > or = 6. The colored Cd-PPT complex was floated quantitatively with oleic acid (HOL) surfactant at pH 6.5, exhibiting maximum absorbance at 520 nm and having a molar absorptivity of 2.4 x 10(5) L mol(-1) cm(-1). The stability constant of the formed complex is 1.5 x 10(12); log K = 12.2. Beer's law was obeyed over the concentration range 0.01-0.34 mg/L. The Sandell sensitivity and relative standard deviation are 0.4 ng/cm2 and 2.6%, respectively. The results obtained spectrophotometrically were compared to those obtained by AAS analysis. The analytical parameters affecting flotation and hence determination have been thoroughly investigated. The proposed procedure was successfully applied to the determination of Cd(II) traces in certified and real human hair samples as well as in natural waters. The structure of the complex formed and the mechanism of flotation were proposed.     

Solochrome Black P. V. as a new reagent in chelatometry

Summary Solochrome Black P. V. with its distinct acid-base properties has proved to be a suitable reagent for the spectrophotometric microdetermination of magnesium either alone or in the presence of zinc, calcium, cobalt, or copper. Interference due to many cations is simply eliminated. Spectrophotometric titration of magnesium with EDTA is investigated. Sensitivity of the method allows determining of 0.05 to 3 ppm Mg with reasonable accuracy.

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Zusammenfassung Solochromschwarz P. V., das als Säure-Base-Indicator verwendet werden kann, ist auch ein geeignetes Reagens zur spektrophotometrischen Mikrobestimmung von Magnesium. Zink, Calcium, Kobalt, Kupfer und andere Kationen können in einfacher Weise maskiert werden. Die spektrophotometrische Titration des Magnesiums mit ÄDTA-Lösung wird ebenfalls untersucht. 0,05–3 ppm Mg können mit guter Genauigkeit bestimmt werden.

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Part II:Khalifa, H., and M. M.Khater: Z. analyt. Chem.183, 241 (1961).     

A rapid potentiometric method for analysis of some minerals and basic refractories

Rapid and quite reliable procedures for analysis of phosphate, quartzite and fluorspar-minerals; chromite, chromemagnesite and magnesite chrome bricks-basic refractories are described. They are based on titrating unconsumed EDTA with Hg(II)-nitrate using silver amalgam as the indicator electrode, with breaks of reasonable order of magnitude lying within the immediate vicinity of the expected end points.