Homochiral imidazolium-based dicarboxylate silver(I) compounds: synthesis, characterisation and antimicrobial properties

Abstract

Complexes [Ag(L^R)], 2 (L^R = 2,2'-(imidazolium-1,3-diyl)di(2-alkylacetate)), were prepared by treatment of compounds HL^R, 1, with Ag₂O. They were characterised by analytical, spectroscopic (IR, ¹H and ¹³C NMR and polarimetry) and X-ray methods (2c, 2c' and 2e). In the solid state, these compounds are novel one-dimensional or two-dimensional coordination polymers in which silver(I) cations are connected via the chiral [L^R]^- anion with unprecedented coordination modes. The antimicrobial properties of these complexes were evaluated. 2a and 2b' showed the best antimicrobial properties (minimal inhibitory concentrations and minimal bactericidal concentration) for Pseudomonas aeruginosa and Escherichia coli pathogens. Eutomers 2b' and 2c' showed slightly better antimicrobial properties than their respective enantiomers 2b and 2c.