Low-toxicity complexes with nitrogen-containing ligands as promising new agents for treatment and prevention of free radical states

A method for synthesis of complexes with 1,5-pentamethylenetetrazole ligand was proposed. These compounds hold promise for antioxidant treatment of so-called “free radical” diseases of different geneses, including those caused by unfavorable environmental factors. The antioxidant activity of the complexes synthesized was tested by two independent methods: by assessing the ability to inhibit lipid peroxidation and by measuring the SOD-like activity.     

Synthesis and properties of an energetic complex pentaamminecobalt (III) perchlorate,with 4-amino-1,2,4-triazole as ligand

Energetic metal complex, 4-amino-1,2,4-triazole-N¹(N²) pentaamminecobalt(III) perchlorate, was produced by the anation reaction of aqua pentaamminecobalt(III) perchlorate with 4-amino-1,2,4-triazole. The thermal decomposition of the metal complex and its mixtures with 1,1-diamino-2,2-dinitroethylene (FOX-7) was studied.     

Synthesis and spectral characteristics of the combined ligand copper complex with proline and corazole

Synthesis of the combined ligand complex of copper(II) prolinate bis(1,5-pentamethylenetetrazole) [Cu(PMT)₂](Pro)₂ was carried out. The product is interesting as a biologically active compound. It is obtained by reaction of copper carbonate with proline followed by further reaction with corazole. The composition and structure of the complex were confirmed by elemental analysis and data of UV, IR, and ¹H NMR spectroscopy. The complex was characterized in detail by the method of circular optical dichroism.     

Five-membered 2,3-dioxoheterocycles. 28. Reaction of 5-aryl-2,3-dihydrofuran-2,3-diones with thioamides and thiosemicarbazides

The reaction of 5-aryl-2,3-dihydrofuran-2,3-diones (I) with thiocarbonyl compounds has been described only for thiourea. The products of this reaction are 3-aryl-5-phenacylidene-4-oxoimidazolidine-2-thiones [2]. It seemed of interest to study the conversion of the furandiones (I) with a wider range of thiocarbonyl compounds such as thioamides and thiosemicarbazides.For Communication 27 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1461–1464, November, 1992.     

High-energy complex copper(II) perchlorate with 1,5-pentamethylenetetrasole as ligand

Possibility of obtaining an energy-saturated metal complex, copper tetrakis[cyclopentamethylenetetrasol] perchlorate, was studied by reacting copper(II) perchlorate hexahydrate with cyclopentamethylenetetrazol. The composition and structure of the complex were confirmed by elemental analysis and UV, IR, ¹H NMR, and ESR spectroscopies. The thermal decomposition of the metal complex synthesized was analyzed and its explosive characteristics and combustion law, as well as the combustion law of a model formulation of a composite solid propellant with addition of the complex, were determined.     

Mechanism of hydrolysis of azalactones catalyzed by a complex of Cu(II) with (S)-2-[(N-benzylpropyl)amino]benzaldoxime

The hydrolysis of 2-methyl-4-benzyl-5(4H)oxazolone (MBA) in a mixture of water and MeCN has been studied — both the spontaneous reaction and that catalyzed by a complex of Cu(II) with (S)-2-[(N-benzylpropyl)amino]benzaldoxime (1). It has been shown that the complex 1 is an effective catalyst for the hydrolysis of MBA (chymotrypsin does not catalyze MBA hydrolysis). The mechanism of MBA hydrolysis catalyzed by this complex includes the formation of a mixed catalyst—substrate complex in which the MBA is coordinated with the metal ion through the N ³ atom. It is suggested that the oxygen atom of the ionized oxime group in such a complex attacks the imine C ² atom of the MBA intramolecularly; this is the rate-determining stage. The change in the order of hydrolysis with respect to the catalyst from 1 to 1/2 when the concentration of 1 is increased indicates that the complex catalyst exists in aqueous solution in two forms, dimeric and monomeric, which are in equilibrium, and only the monomeric form of the complex is responsible for the catalysis. With an excess of the substrate we observe inhibition of the MBA hydrolysis — possibly an indirect indication of participation in the transition state by a water molecule coordinated in an apical position of the complex, which is displaced by excess substrate.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, Moscow 117813. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 536–546, March, 1992.     

Construction of a certain class of line graphs

The construction of a line graph is described on the basis of a finite bipartite graph, for a given k > 1. An algorithm is set forth for the construction of the line graph and an example of its use is given.Translated from Dinamicheskie Sistemy, No. 4, pp. 107–116, 1985.     

Properties of Moving Discrete Breathers in Beryllium

Physics of the Solid State - Discrete breathers (DBs) have been described among pure metals with face-centered cubic (FCC) and body-centered cubic (BCC) lattice, but for hexagonal close-packed...     

New 2-methylbenzimidazole derivatives

New 2-methylbenzimidazole derivatives with a methyl, ethyl, or phenyl group at position 1, and a hydroxymethyl, aldehyde, or ß-carboxyl group at position 5 are synthesized. Imidocyanine dyes with aldehyde and ß-carboxyl groups in the heterocyclic portions are obtained, and their main light absorption maxima determined.     

Complexation and hydrogenation of methionine-containing N-acetyle-dehydrodipeptides

The hydrogenation of the Fe^II complex ofN-Ac-Phe-(S)- or -(R)-Met over a Pd/C catalyst affords mainlyN-Ac-(R)-Phe-(S)-Met orN-Ac-(S)-Phe-(R)-Met, correspondingly. In the reaction of mixed dipeptide complexes with Ca^II and Fe^II the predominance of one of the diastereomers increases from 26 % (for complexes with Fe ions) to 38 %.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 545–546, March, 1994.The work was financially supported by the Russian Foundation for Basic Research (project No. 93-03-4646).