Stereospecific ligands and their complexes. Part XXI. Synthesis, characterization, circular dichroism and antimicrobial activity of cobalt(III) complexes with some edda-type of ligands. Crystal structure of potassium-Δ-(−)589-s-cis-oxalato-(S,S)-ethylenediamine-N,N′-di-(2-propanoato)-cobaltate(III)-semihydrate, K-Δ-(−)589-s-cis-[Co(S,S-eddp)(ox)]·0.5H2O

Abstract

The octahedral cobalt(III) complexes with (S,S)-ethylenediamine-N,N′-di-2-propionic (S,S-eddp) and (S,S)-ethylenediamine-N,N′-di-2-(3-methyl)-butanoic (S,S-eddv) acids and oxalato and malonato ligands, as additional bidentate ligands, were prepared and characterized. The complexes were purified by ion-exchange chromatography. The geometry of the complexes has been supposed on the basis of the infrared, electronic absorption and NMR spectra. The Δ absolute configurations of the isolated complexes have been predicted on the basis of their circular dichroism (CD) spectra and it was confirmed by single-crystal X-ray analysis of potassium-Δ-(−)589-s-cis-oxalato-(S,S)-ethylenediamine-N,N′-di-(2-propanoato)-cobaltate(III)-semihydrate, K-Δ-(−)589-s-cis-[Co(S,S-eddp)(ox)]·0.5H2O. Antimicrobial activity of ligands and obtained cobalt(III) complexes was evaluated by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) in relation to 13 species of microorganisms (five strains of pathogenic bacteria, five species pathogenic fungi and three species of probiotic). Tested ligands and complexes demonstrated moderate and low antibacterial and antifungal activity. There was no difference in activities between the ligands and complexes.