S. N. Bolotin

NMR, EPR, and mass spectroscopy estimates of the antiradical activity of water with modified isotope composition

The dynamics of the change in the deuterium content in plasma of laboratory animal blood is studied by nuclear magnetic resonance spectroscope using water with modified isotope composition. The change in deuterium content in lyophilized animal tissues is determined by mass spectrometry. The content of paramagnetic centers in a dose and in pathology is determined on an electron paramagnetic resonance spectrometer.

Potentiometric study of reactions of rare-earth elements with 3-allylpentanedione in a water-dioxane medium

Reactions of the ions of La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb, and Lu with 3-allylpentanedione (HL) in a water-dioxane (50 vol%) medium were studied by pH-metric titration. Stability constants of LnL2+ and LnL2+ complexes and pH range where these compounds are mainly formed were determined. The dependence of the stability constants on the atomic number of an element has a characteristic break on the gadolinium ion and shows that the stability of the complexes increases as the size of Ln3+ ions decreases.

Modifying the surface of a hydrogen permselective palladium–silver membrane

Thin films of Pd–23% Ag composition are obtained by means of magnetron sputter deposition. The surfaces of the films are modified via the electrolythic deposition of finely divided palladium. The hydrogen permeabilities of samples of membranes (both smooth and modified with palladium black) are compared. A marked increase in the hydrogen permeability of the modified membrane is observed, compared to the smooth membrane. The dependence of the rate of hydrogen fluence on the excess pressure is approximated by a curve of the first order, demonstrating the limitations of the process of hydrogen permeation by hydrogen superficial dissociation.

Effect of the condition of synthesis on the composition and structure of copper(II) complexes with benzimidazole

The composition and structure of copper(II) benzimidazole complexes obtained by the reaction of CuCl2 with benzimidazole (BIm) were determined. At pH 4.5–5.5, depending on the reactant ratio, dimeric compounds with the composition Cu(BIm)4Cl2 · 2H2O and Cu(BIm)2Cl2 · H2O are formed. They are converted to monomers at about 200°C. At pH > 8, irrespective of the reactant ratio, the polymer (Cu(OH)L)n is formed. The complexation of copper(II) with benzimidazole in water and aqueous dioxane was studied by potentiometry, and the stability constants of the complex compounds and their dependence on the solvent composition were determined.

Sorption of chromium(VI) on ion-exchange resins and sorbents

Sorption of Cr(VI) on AV-17 and EDE-10P anion exchangers, KU-2 and KB-4 cation exchangers, activated charcoal, and foamed graphite (STRG) is studied.

Preparation and properties of silica gel with immobilized formazan group

A new sorption material, silica gel with covalently immobilized formazan group, was suggested and characterized. The material was prepared by coupling the immobilized aryldiazonium salt with benzaldehyde phenylhydrazone. The equilibrium and kinetic characteristics of the sorption of Cu(II), Co(II), Ni(II), and Cd(II) from solutions onto the modified silica gel were determined. The material proved to efficiently concentrate Cu(II) from multicomponent solutions. The coordination surrounding of Cu(II) in the complex on the sorbent surface was determined by ESR.

Structure of Copper(II) Complexes with 2-[2-Hydroxy-Phenil]-4,4-Diphenyl-1,2-Dihydro-4H-3,1-Benzoxazine in Chloroform

Electronic spectra of copper(II) complexes CuL2andCu2L2Ac2 (L-2-[2-hydroxy-phenil]-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine, Ac –CH3COO−) (L) in chloroform are studied. It is shown that complex Cul2 has rhombic bipyramid polyhedron and complex Cu2L2Ac2 has tetragonal pyramidal polyhedron of copper ion. Results of definition of geometry for complexes in solution correlate with structure of solid complexes.

Effect of amalgamation on the passivation of transition metals in their anodic dissolution in tetrahydroadipic acid solutions

Effect of anode amalgamation on the degree of passivation of the electrodes and on the current efficiency in electrosynthesis of coordination compounds of copper(II), nickel(II), zinc(II), and cadmium(II) with galactaric acid was studied. An improvement of anodic synthesis characteristics was observed when amalgamated zinc, copper, and cadmium were used. Complex compounds of 1 : 1 composition were obtained and the structure of the coordination environment of the metal ion was determined by IR spectroscopy.

Influence of the method of synthesis on the composition and structure of copper(II) complexes with galactaric acid

The influence of the conditions and the method of synthesis on the composition of copper(II) complexes with galactaric acid (H2Gala) has been studied. In aqueous and water-DMSO solutions, 1 : 1 complexes are formed. Depending on the procedure and conditions of the synthesis, CuGala · 4H2O, Cu(HGala)2 · 4H2O, and (CuOH)2Gala · 2H2O compounds have been obtained. The structure of the coordination environment of the metal ion has been identified by IR spectroscopy.

Structures of copper(II) complexes with dihydrobenzoxazine derivatives in chloroform

AbstractCopper(II) complexes CuL2 (HL = 2-(2-hydroxyphenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine and 2-(2-hydroxy-5-nitrophenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine) in chloroform were studied by EPR and electronic absorption spectroscopy. It was found that the complexation involves the azomethine forms of the ligands, which are coordinated by the Cu atom through the phenol and azomethine fragments of both ligands. The electronic absorption spectra were decomposed into Gaussian components to determine the d-d transition energies. The parameters of the complexation were calculated in terms of the angular overlap model. The order of energy arrangement of the orbitals of the central atom was determined: