Synthesis and antimicrobial activities of silver(i) sulfanylcarboxylates. Structural isomers with identically or unequally coordinated Ag centers in an Ag4S4 ring

Abstract

We have investigated the reactions of silver nitrate and 3-(aryl)-2-sulfanylpropenoic acids [H₂xspa, x: p = 3-phenyl-, f = 3-(2-furyl)-, t = 3-(2-thienyl)-, py = 3-(2-pyridyl)-] and 2-cyclopentylidene-2-sulfanylacetic acid (H₂L) in 1 : 1 and 2 : 1 molar ratios. The 1 : 1 molar ratio gave compounds of type [Ag(HL)]; reaction of these compounds with diisopropylamine and NaOH gave [HQ][Ag(L)] (HQ = diisopropylammonium) and Na[Ag(L)]·H₂O, respectively. These compounds, as well as those of type [Ag₂(L)] obtained with the 1 : 2 molar ratio, were isolated and characterized by IR and NMR (¹H and ¹³C) spectroscopy. ¹⁰⁹Ag NMR spectroscopy and ESI-MS spectrometry were also used in some cases. The crystal structures of [HQ][Ag(pspa)] (11), in which the presence of structural isomers was detected, and [HQ][Ag(cpa)] (15) were determined by X-ray diffractometry. The antimicrobial activity of the complexes against E. coli, S. aureus, B. subtilis, P. aeruginosa/Resistant P. aeruginosa, and C. albicans was tested.