Organometallic Gold(III) Complexes with Tridentate Halogen‐Substituted Thiosemicarbazones: Effects of Halogenation on Cytotoxicity and Anti‐Parasitic Activity

Chemical properties and biological activity of Au(III) compounds obtained from dichlorido[2‐(dimethylaminomethyl)phenyl‐C1,N]gold(III), [Au(damp‐C1,N)Cl2], and halogenated, potentially tridentate thiosemicarbazones have been studied. The results of this work show that the complexation of the halogenated thiosemicarbazones with Au(III) enhances their stability against hydrolysis and retains or enhances their anti‐parasitic activity. Fluorination in the periphery of the ligands has expectedly no influence on the structural chemistry of the obtained Au(III) complexes, but modulates their biological behaviour. Best results with a remarkably high selectivity index for the trypomastigote form of Trypanosoma cruzi were obtained with the complex containing the ligand, which presents a 3,5‐fluorine substitution in meta‐position of an aromatic ring, [Au(dampH)(L‐3,5‐F)]Cl. Halogenation of thiosemicarbazone ligands in cationic organometallic Au(III) complexes enhances their stability against hydrolysis and retains or enhances their activity against the parasite trypanosoma cruzi. Best results were obtained with a ligand, which contains two fluorine atoms in 3,5‐positions of an aromatic ring, [Au(dampH)(L‐3,5‐F)]Cl.