THE DIRHENIUM(III) COMPLEX COMPOUNDS WITH IMIDAZOLE AND BENZIMIDAZOLE

Abstract

Imidazole and it’s derivatives are structural fragments of certain enzymes, aminoacids, alkaloids and drugs. To date, the participation of imidazole in human metabolism, especially in the biosynthesis of natural purine bases of RNA and DNA, has been proven. Benzimidazole is one of the most used compound in medical chemistry. The various derivatives of substances, that exhibit analgesic, antidiabetic, anti-inflammatory, antitumor and antiviral activities were synthesized based on benzimidazole. This fact paves the way for the synthesis of antimetabolites, which can delay biosynthesis during biotransformation and inhibit the growth of malignant tumors. Thus, in the present work, the interaction of complex compounds with a single cluster fragment of Re 2 6+ (NBu 4 ) 2 Re 2 Cl 8 and trans-tetrachlorodi-μ-alkylcarboxylates of dirhenium(III) with representatives of the azole class – imidazole and benzimidazole was studied under various conditions. As a result of the experiments, methods for the synthesis of cis-[Re 2 (X) 4 Cl 4 (CH 3 CN) 2 ]Cl 2 (X is imidazole, benzimidazole) in an electron-donating organic solvent – CH3CN under heating in an inert atmosphere were developed. The starting materials were (NBu4)2Re2Cl8 and the selected azoles at a molar ratio of 1:10. The yield of the target compounds was 67-75%. We also investigated the reaction between trans-tetrachloridi-μ-alkylcarboxylates of dirhenium(III) and indicated azoles in a non-donor solvent (1,2-dichloroethane) in inert atmosphere at a molar ratio of reactants of 1:20. As a result of the interaction, complex compounds of the general formula (XH) 2 Re 2 Cl 8 (X – imidazole, benzimidazole) are formed, in which azoles are cations. The yield of reaction products was 83-87%. All target substances are synthesized, isolated in individual state, their spectral properties are investigated. The composition and structure of the obtained complex compounds were confirmed by IR- and NMR- spectroscopy on 1H and 13C, conductometry, and electronic absorption spectroscopy.