Synthesis and antimicrobial activities of silver(I) 3-(substituted phenyl)sulfanylpropenoates

We investigated the reactions of silver nitrate with 3-(substituted phenyl)-2-sulfanylpropenoic acids H2L [L = xspa, where spa = 2-sulfanylpropenoato and x ∈ {Clp = 3-(2-chlorophenyl)-, -o-mp = 3-(2-methoxyphenyl)-, -o-hp = 3-(2-hydroxyphenyl)-, -p-hp = 3-(4-hydroxyphenyl)-, diBr-o-hp = 3-(3,5-dibromo-2-hydroxyphenyl)-}] in 1:1 and 2:1 molar ratios. The 1:1 reactions gave compounds of type [Ag(HL)], which reacted with NaOH to afford Na[Ag(L)]·xH2O (x = 1 or 2) and with diisopropylamine to afford [HQ][Ag(L)] (HQ = diisopropylammonium). The 2:1 reactions gave products of type [Ag2(L)]. All the new compounds were isolated and characterized by IR spectroscopy, and all except the 2:1 adducts (which were insoluble) were studied by 1H and 13C NMR spectroscopy; ESI-MS spectrometry was also used for [HQ][Ag(L)] and Na[Ag(L)]·xH2O, and the crystal structures of H2Clpspa and [HQ][Ag(Clpspa)] were determined by X-ray diffractometry. The antimicrobial activities of the complexes against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa and carbapenem-resistant P. aeruginosa were evaluated and compared with those of Ag(I) complexes with other aryl sulfanylpropenoates or related ligands.

Graphical abstractThe reaction of 3-(aryl)-2-sulfanylpropenoic acids (H2L) with silver nitrate afforded complexes of the type [Ag(HL)], [Ag2(L)], [HQ][Ag(L)] (HQ = diisopropylammonium) and Na[Ag(L)]·xH2O. The antimicrobial activities of the complexes against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa and carbapenem-resistant P. aeruginosa were evaluated.Figure optionsDownload full-size imageDownload as PowerPoint slide