Yu. I. Sal'nikov

2,4-diamino-6-(acetohydrazidomethylsulfinylmethyl)-1,3,5-triazine. State in solution, acid-base and complexing properties

Solutions of a new drug, 2,4-diamino-6-(acetylhydrazidomethylsulfonylmethyl)-1,3,5-triazine, exhibiting tuberculocidal activity were studied using the methods of pH-metry, spectrophotometry, mathematical simulation of equilibria (CPESSP software), and molecular mechanics. Protolytic properties of the compound in the medium of aqueous dimethylsulfoxide (40 vol % of DMSO) were characterized. The composition of the copper(II) complex of this compound was determined and its stability constants were calculated. Based on the absorption spectra in the UV and visible regions the complexing ability of 2,4-diamino-6-(acetylhydrazidomethylsulfonylmethyl)-1,3,5-triazine toward nickel(II) and cobalt(II) were characterized in comparison with copper(II) under the same conditions.

Micellization and catalytic properties of polyethylene glycol 600 monolaurate in toluene

The reaction of 4-nitrophenyl bis(chloromethyl)phosphinate with 2-dialkylaminomethylphenols in toluene solutions of polyethylene glycol 600 monolaurate was studied spectrophotometrically. The effect of structural features of the micellar system on the catalytic effect depends on the nucleophile hydrophobicity. Micellization of the nonionic surfactant was studied by dielectrometric titration and by the kinetic method. The aggregation numbers and the composition of detergent aggregates were determined.

The reaction of 2-aminomethylphenols and their copper(II) complexes with esters of phosphorus acids

Abstract2-Alkyl- and 2-dialkylaminomethylphenols (AMP) with different hydrophobic substituents at the nitrogen atom and their copper(II) complexes (CAMP) react with the esters of phosphorus acids in aqueous solutions of ethanol in two stages: phosphorylated AMP (PAMP) are formed at the first stage and then hydrolyzed to the corresponding acids. The reactivity of AMP and PAMP significantly decreases when the hydrophobicity and steric hindrances of substituents at the nitrogen atom increase. An inverse dependence was found for CAMP.

Effect of sodium dodecyl sulfate on the reactivity of copper(II) complexes with 2-dimethylaminomethylphenol

The effects of the anionic surfactant sodium dodecyl sulfate on complex formation of 2-dimethylaminomethylphenol (1) with copper(u) in aqueous solutions and on the kinetics of the reactions of copper(n) complexes of 1 with 4-nitrophenylbis(chloromethyl)phosphinate (2) were studied. The reactivities of the complexes in these reactions are higher than that of 1 at all concentrations of SDS studied (0.010–0.200 mol L−1 with pH 7–9.

Optical activity, solvation state, and conformations ofL-α-alanine in water-organic solvents

The solvation effect on the conformational equilibrium ofL-α-alanine in binary water-organic solvents (H2O-acetonitrile, H2O-DMF) was studied. This manifests itself in changes in the optical activity and CD intensity. Equilibrium constants for the substitution of water molecules by organic solvent molecules were determined.

Paramagnetic Birefringence of Heteronuclear Erbium(III), Thulium(III), and Iron(III) d- and dl-Tartrates

Formation of heteronuclear erbium(III), thulium(III), and iron(III) d- and dl-tartrates was studied by proton magnetic relaxation, pH-metry, and paramagnetic birefringence in combination with mathematical simulation. The paramagnetic birefringence constants mP of the complexes were calculated.

Effects of surfactants on complex formation of CuII with 2-dimethylaminomethylphenol

The effect of cationic (cetyltrimethylammonium bromide) and nonionic (Triton X-100) surfactants on the complex formation of CuII with a bifunctional ligand, 2-dimethyl-aminomethylphenol, in water was studied by spectrophotometry, pH-metry, and mathematical modeling of equilibria in solutions. The character of complex formation depends on the nature and concentration of surfactants. The dependence of complex formation constants on the concentration of surfactants is discussed.

STRUCTURE OF DYSPROSIUM MONOTARTRATE IN AQUEOUS SOLUTION FROM MAGNETIC DOUBLE REFRACTION AND MOLECULAR MECHANICS DATA

AbstractpH-Metering and magnetic double refraction are used to determine the molar constant of magnetic double refraction of dysprosium monotartrate DyH2L+ (H4L is tartaric acid). A molecular mechanics technique (Dashevskii-Plyamovatyi model) was used to model the structure of the ligand and hydrate surroundings of dysprosium(III) in DyH2L+. Theoretical molar constants of magnetic double refraction calculated from the molecular mechanics data (CONKERR program) were compared with the experimental values; the most probable models of the surroundings of the dysprosium(III) are established.

Composition, structure, and anisotropy of magnetic properties of d- and dℝ-tartrates of Dy3+ from proton magnetic relaxation and magnetic birefringence data

We have determined the composition and stability of d- and dℝ-tartrates of Dy3+. In the pH region 4.0–7.0, we have shown that binuclear particles are formed. The relative stability of isomeric d- and dℝ-tartrates of Dy3+ is determined only by the statistical factor. From data on the paramagnetic birefringence effect, binuclear d- and dℝ-tartrates of dysprosium(III) have a polycyclic structure including six five-membered metallocycles, two of which are condensed with the central twelve-membered ring. The paramagnetic anisotropy of Dy3+ in the studied dimers has twice the absolute value of the anisotropy of the aqua ion of Dy3+ (Δk=−2860·10−29 cm3). Using the magnetic susceptibility measurements, we have demonstrated the virtually complete absence of Dy3+−Dy3+ magnetic interactions in binuclear d- and dℝ-tartrates.

Composition, properties, and structure of palladium(II) chlorides in aqueous solution

The composition, stability, and structure of palladium(II) chloride complexes in hydrochloric acid media have been determined using nuclear-magnetic relaxation, magnetochemical methods, and Rayleigh light scattering. The predominant form in solution for palladium(II) concentrations greater than 0.005 moles/liter is the octahedral Pd6Cl12 or Pd6Cl142−, which has antiferromagnetic properties in contrast with the paramagnetic properties of the mononuclear aquachloride. The polarizability anisotropy of Pd-Cl bonds with terminal and bridging chlorine atoms has been determined.