Semiquantitative determination of aromatic andα,β-unsaturated aldehydes by circular thin-layer chromatography

Summary A method for semiquantitative determination of aromatic and,-unsaturated aldehydes such as salicylaldehyde, anisaldehyde, vanillin, veratraldehyde, piperonal, cinnamaldehyde, furfural andp-dimethylaminobenzaldehyde by making circular spots of their isonicotinoyl hydrazones on chromatoplates with circular thin-layer Chromatographic apparatus and their comparison with sensitivity standards has been described. The accuracy is ± 5% and the method is rapid, simple and economical.

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Zusammenfassung Ein Verfahren zur semiquantitativen Bestimmung aromatischer und,-ungesättigter Aldehyde wie Salioylaldehyd, Anisaldehyd, Vanillin, Veratrumaldehyd, Piperonal, Zimtaldehyd, Furfural und p-Dimethylaminobenzaldehyd durch Dünnschicht-Ringchromatographie ihrer Isonikotinsäurehydrazone und Vergleich mit Standardchromatogrammen wurde beschrieben. Die Genauigkeit beträgt ±5%.

     

Aromatic polyether, -ketone, -sulfones as laminating resins. XII. Derivatives of 2,2′-diphenylethynyldiphenyl which cure by an intramolecular cyclization

Polymers made from 2,2′-diiododiphenyl-4,4′-dicarbonyl dichloride, diphenyl ether, and isophthaloyl chloride have been made and converted to the 2,2′-diphenylethynyl derivatives. Introduction of units of isophthaloyl chloride reduced the melting point of these polymers to about 200°C, and they could then be cured by heating. A good glass laminate was prepared and cured from one of the polymers.     

Correction to: Idealness of k-wise intersecting families

Mathematical Programming - A Correction to this paper has been published: 10.1007/s10107-020-01587-x     

Idealness of k-wise intersecting families

Mathematical Programming - A clutter is k-wise intersecting if every k members have a common element, yet no element belongs to all members. We conjecture that, for some integer $$k\ge 4$$ , every...     

A new step size rule for the superiorization method and its application in computerized tomography

Numerical Algorithms - In this paper, we consider a regularized least squares problem subject to convex constraints. Our algorithm is based on the superiorization technique, equipped with a new...     

Quantum game approach for capacity allocation decisions under strategic reasoning

From a common point of view, quantum mechanics, psychology, and decision science disciplines try to predict how unruly systems (atomic particles, human behaviors, and decision makers’ choices) might behave in the future. Effective predicting outcome of a capacity allocation game under various allocation policies requires a profound understanding as how strategic reasoning of decision makers contributes to the financial gain of players. A quantum game framework is employed in the current study to investigate how performance of allocation policies is affected when buyers strategize over order quantities. The results show that the degree of being manipulative for allocation mechanisms is not identical and adopting adaptive quantum method is the most effective approach to secure the highest fill rate and profit when it is practiced under a reasonable range of entanglement levels.

     

Reactions of [(Cp)2Ti(NCS)2] as a potential metalloligand; synthesis and physico-chemical investigations of novel heterobimetallic complexes

Summary Bis(cyclopentadienyl)titanium(IV) diisothiocyanate [(Cp)₂-Ti(NCS)₂] reacts with MCl₂ (M = Cu, Pd or Pt), [CuCl(PPh₃)₃], [RuCl₂(PPh₃)₃] and [RuCl₂(DMSO)₄] (DMSO = dimethylsulphoxide) giving solid compounds of stochiometry [(Cp)₂Ti(-NCS)₂MCl₂] (M = Cu, Pd or Pt), [(Cp)₂Ti(-NCS)₂CuCl(PPh₃)], [(Cp)₂Ti(-NCS)₂-RuCl(PPh₃)₂]Cl and [(Cp)₂Ti(-NCS)₂RuCl₂(DMSO)2]. These products have been characterized by physicochemical and spectroscopic methods.     

NMR study of the stoichiometry,stability and exchange kinetics of complexation reaction between Pb2+ ion and 18-crown-6 in binary acetonitrile-water mixtures

Proton NMR was used to study the complexation reaction between lead ion and 18-crown-6 in a number of binary acetonitrile-water mixtures. Formation constant for the resulting 11 complexes in different solvent mixtures was determined by computer fitting of the chemical shift-mole ratio data. There is an inverse relationship between the complex stability and amount of water in the mixed solvent. The dissociative kinetics of the complex was studied by proton line-shape analysis. The Arrhenius plots showed a distinct isokinetic temperature at about 25°C at which the decomplexation rate is more or less independent of the solvent composition. the complexation rate and the activation parameters E _a , H and S, for the exchange have been determined and found to be strongly solvent dependent. There is actually a linear relationship between the mole fraction of acetonitrile in the mixed solvent and logarithm of the stability constant as well as activation parameters.