From Pyrone to Thiopyrone Ligands−Rendering Maltol-Derived Ruthenium(II)−Arene Complexes That Are Anticancer Active in Vitro

Ru(II)−arene complexes with pyrone-derived ligands are rendered active against cancer cells by replacement of the coordinated O,O donor with an S,O donor. The different stabilities of these systems may explain the observed influence of the donor atoms on the anticancer activity in vitro.