Azo derivative of 2-thenoyltrifluoroacetone as a reagent for the photometric determination of copper(II)

1-(2-Thenoyl)-4-trifluoro-2-[2-hydroxy-3-sulfo-5-nitrophenylazo]butadione-1,3 (H₂L) was synthesized from 2-thenoyltrifluoroacetone. The formation of a copper(II) complex of the synthesized reagent was studied in the presence and absence of 8-hydroxyquinoline (HR). Monoligand [Cu(HL)₂] and mixed-ligand [Cu(HL)₂HR] compounds were obtained at pH 4 and 3, respectively. The ratio of components in the monoligand and mixed-ligand compounds were 1 : 2 and 1 : 2 : 1, respectively. Beers law was obeyed in the ranges of copper concentrations from 0.20 to 2.56 and from 0.25 to 2.56 µg/mL, respectively. The dissociation constants of the reagent were .K₁ = 4.25µ0.01 and .K₂ = 8.20µ0.01 . The stability constants of [Cu(HL)₂] and [Cu(HL)₂HR] complexes were K₁ = 4.96µ0.03 and 4.92µ0.01, respectively. A procedure was developed for the photometric determination of copper(II) in rocks.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 2, 2005, pp. 157–161.Original Russian Text Copyright © 2005 by Alieva, Chyragov, Makhmudov.This revised version was published online in April 2005 with corrections to the author names and book review format.     

Preconcentration of Cadmium and Zinc on a Chelating Sorbent and Their Determination by Flame Atomic Absorption Spectrometry

A method is developed for cadmium and zinc preconcentration on a minicolumn packed with a new chelating polymer sorbent. The effects of the test solution pH and volume, the sample matrix composition, the eluent volume, and the sample and eluent flow rates are studied. Zinc and cadmium in the eluate are determined by flame atomic absorption spectrometry. Under optimal conditions, the determined ion recovery is more than 95%. The detection limits (3σ, n = 20) are found to be 15.0 (Cd) and 17.2 (Zn) ng/mL. The developed method is employed for cadmium and zinc determination in samples of seawater and water obtained after oil pumping.     

TPD study of catalyst surface acidity

Acidity of catalyst surfaces of different nature such as -Al₂O₃, natural zeolite-clinoptilolite, and synthetic zeolite zeokar by adsorption of ammonia over a wide temperature range has been studied. Ammonia is adsorbed on the catalysts with different strengths, as evidenced by the presence of different types of acid sites.

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Pyroelectric properties and structural defects of a layered TlInS2 crystal doped with lanthanum

The results of investigations of the pyroelectric current in a layered TlInS₂ crystal doped with lanthanum are presented. A comparative analysis of the obtained results and data of photo-induced current transient spectroscopy has been performed. The revealed features of the contribution from electrically active defects to pyroelectric properties of the crystal have been discussed.     

Ionic telomerization of 1-chloro-2,3-epoxypropane with allyl alcohol and properties of products obtained

Ionic telomerization of 1-chloro-2,3-epoxypropane with allyl alcohol in the presence of boron trifluoride etherate as a route to halogenated epoxy oligoethers was studied. Selective chlorination or bromination of the intermediate oligo(chlorohydrin), followed by dehydrochlorination (epoxidation) of the intermediate oligohalohydrins with NaOH, was performed. The synthesized products are effi cient as active diluents for a compound based on ED-20 resin.     

Synthesis and polymerization of (p-Vinylphenyl)cyclopropylmethyl cinnamate

(p-Vinylphenyl)cyclopropylmethyl cinnamate was synthesized, and its radical polymerization was performed. The synthesized polyfunctional polymers containing UV-sensitive >C=O, >C=C<, and ? groups exhibit high photosensitivity. Photochemical cross-linking of the polymers was studied. The polymers synthesized can be used for preparing photosensitive materials.     

Mode analysis in optics through fractional transforms

The relationship between the mode content and the fractional Fourier and fractional Hankel transforms of a function is established. It is shown that the Laguerre-Gauss spectrum of a rotationally symmetric wave front can be determined from the wave front's fractional Hankel transforms taken at the optical axis.