Mixed-valence hexanuclear CoII,III complex with amidoxime: synthesis, structure, and in vitro biological activity against the non-pathogenic strain of Mycolicibacterium smegmatis

• Published in: Russian chemical bulletin 2022-10, Vol.71 (10), p.2172-2178
• Main Authors: Lutsenko, I. A., Vologzhanina, A. V., Kayukova, L. A., Yergalieva, E. M., Koshenskova, K. A., Bekker, O. B., Dorovatovskii, P. V., Eremenko, I. L.
• Format: Article
• Language: English
• Subjects: Biological activity; Chelation; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Cobalt; Coordination; Full Articles; Inorganic Chemistry; Ligands; Organic Chemistry; Oxygen atoms
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-022-3643-7

The reaction of cobalt(ɪɪ) chloride with p -Br-benzoyl-β-(piperidin-1-yl)propioamid-oxime (L init ) in methanol leads to the hydrolysis of the ligand at the -OCO- ester bond and the formation of the mixed-valence hexanuclear ionic complex [Co II 2 Co III 4 (HL) 4 (L) 2 (O)-(Cl) 4 ]Cl 2 •4CH 3 OH ( 1 ) (L is β-(piperidin-l-yl)propioamidoxime). According to the X-ray diffraction data, the ligand (L) in 1 is coordinated to the complexing agent in different modes: the μ 3 -bridging-chelating mode (involving deprotonated amino groups) and the μ 2 - and μ 3 -bridging-chelating modes in the case of a coordinated amino group. Two cobalt atoms of the hexanuclear metal core have a tetrahedral coordination geometry (Co II N 2 Cl 2 ; CN Co II = 4), whereas the other four cobalt atoms are in an octahedral coordination environment of nitrogen and oxygen atoms forming the polyhedra of composition Co III O 3 N 3 and Co III O 4 N 2 (CN Co III = 6). The evaluation of the in vitro biological activity of 1 against the non-pathogenic (virulent H37Rv model) mycobacterial strain of Mycolicibacterium smegmatis showed an increase in the efficiency of complex 1 by more than 4–12 times compared to the previously studied Co II,III complexes.