G. A. Boos

Acid-base properties of bis(hydrazinocarbonylmethyl) sulfoxide and its complex formation with copper(II) and nickel(II)

Behavior of physiologically active compound, bis(hydrazinocarbonylmethyl) sulfoxide, in aqueous solution has been studied by means of potentiometry, spectrophotometry, and mathematical simulation. Protolytic properties of bis(hydrazinocarbonylmethyl) sulfoxide have been described, and the formation of sodium salt has been confirmed. Composition and stability constants of bis(hydrazinocarbonylmethyl) sulfoxide complexes with copper(II) and nickel(II) have been determined, and the complexes structures have been simulated by molecular mechanics method.

1-[5-(Hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate: protolytic properties and complexation reactions

The compound with antituberculosis activity, 1-[5-(hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate, was studied in aqueous dimethyl sulfoxide by potentiometric titration, spectrophotometry, and mathematical simulation of equilibria in solution (the CPESSP program). The protolytic properties of the compound were examined. The compositions and stability constants of its complexes with copper(II) were determined. The geometries of the isocyanurate and its complexes were optimized by molecular mechanics computations.

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.

Solvation state of iron(III) in aqueous solutions of dimethyl sulfoxide. Complex formation ability of iron(III) with respect to derivatives of sym -triazine and bis(hydrazinocarbonylmethyl) sulfoxide

Parameters of the solvation equilibria

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

{\left[ {Fe{{\left( {{H_2}O} \right)}_6}} \right]^{3 + }} + nDMSO \rightleftarrows {\left[ {Fe{{\left( {{H_2}O} \right)}_{6 - n}}{{\left( {DMSO} \right)}_n}} \right]^{3 + }} + n{H_2}O

Solution state and complexing ability of 1,4-bis(amidomethylsulfinyl)butane toward iron(III), copper(II), cobalt(II), nickel(II), and manganese(II)

[Fe(H2O)6]3++nDMSO⇄[Fe(H2O)6−n(DMSO)n]3++nH2O have been determined in aqueous-dimethyl sulfoxide solutions (0–90 vol% DMSO) by means of spectrophotometry and mathematical modeling of equilibria. Iron(III) is not involved in the complex formation with derivatives of sym-triazine: 2,4-diamino-6-(carbamoylmethylsulfinylmethyl)-1,3,5-triazine and 2,4-diamino-6-(acetohydrazidomethylsulfinylmethyl)-1,3,5-triazine in aqueous DMSO medium (40 vol % DMSO). Bis(hydrazinocarbonylmethyl) sulfoxide forms two complexes with iron(III), with 1: 1 and 1: 2 compositions; in contrast to the Cu(II) and Ni(II) complexes, in the iron complexes the ligand exists in the amide form. The most probable structures of the complexes have been revealed by molecular mechanics simulation and (in selected cases) using the DFT/B3LYP/6-31++G(d,p) density functional theory method.

2,4,6-triaminopyrimidine and its associates with bis(hydroxymethyl)phosphinic acid. State in solution, protolytic, and complexing properties

Composition and thermodynamic stability of complexes of 1-[5-(hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate with cobalt(ii), nickel(ii), and iron(iii) in H2O—DMSO medium (60 vol.% DMSO) was studied by spectrophotometry, potentiometric titration, and mathematical modeling (CPESSP program). The geometries of all studied structures were optimized by the MM2 molecular mechanics method to obtain the primary target data (estimates) on coordination pattern of 1-[5-(hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate in complexes with cobalt(ii), nickel(ii), and iron(iii). Cobalt(ii) and nickel(ii) formed the 1 : 1 complexes; while iron(iii) under experimental conditions excluding redox reactions gave the 1 : 1 and 1 : 2 complexes. All complexes contain ligands in neutral form.

Properties of N,N-dimethyl-N′-(2-hydroxybenzyl)ethylenediamine as a ligand to copper(II)

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.