Synthesis, structure and cytotoxicity of triphenylphosphinegold(I) sulfanylpropenoates

The reaction of triphenylphosphinegold(I) chloride in ethanol in a 1:1 molar ratio with the 3-(aryl)-2-sulfanylpropenoic acids H2xspa [x: p = 3-phenyl-, Clp = 3-(2-chlorophenyl)-, -o-mp = 3-(2-methoxyphenyl)-, -p-mp = 3-(4-methoxyphenyl)-, -o-hp = 3-(2-hydroxyphenyl)-, -p-hp = 3-(4-hydroxyphenyl)-, diBr-o-hp = 3-(3,5-dibromo-2-hydroxyphenyl)-, f = 3-(2-furyl)-, t = 3-(2-thienyl)-, -o-py = 3-(2-pyridyl)-; spa = 2-sulfanylpropenoato] gave compounds of the type [Au(PPh3)(Hxspa)], which were isolated and characterized as solids by elemental analysis, IR spectroscopy and FAB mass spectrometry and in solution by 1H, 13C and 31P NMR spectroscopy. The structures of the complexes [Au(PPh3)(HClpspa)], [Au(PPh3)(H-o-mpspa)] and [Au(PPh3)(H-p-mpspa)] · 2/3C3H6O were determined by X-ray diffractometry. Hydrogen bonding was found along with Au–S and Au–P bonds in all cases and weak π–π stacking was found in the H-p-mpspa derivative. The in vitro antitumour activities against the HeLa-229, A2780 and A2780cis cell lines were determined for all complexes.