Kinetic investigation of reactions of a 3-arylidene-2-thiohydantoin derivative with palladium (II) salts

1H NMR spectroscopy was used to monitor the reactions of an arylidene 2-thiohydantoin derivative, 3-((phenylmethylene)amino)-2-thioxo-4- imidazolidinone (3), with PdCl2, cis-[PdCl2(dmso-S)2] and K2[PdCl4] in DMSO-d6 order elucidate reaction kinetics mechanism. The derivative 3 formed cis-[Pd(3-N,S)(dmso-S)2]+ complex (5) PdCl2 cis-[PdCl2(dmso-S)2], while no observed. A two-step mechanism for cis-[PdCl2(dmso- S)2] is proposed, which fast coordination side chain nitrogen occurs first step, chelation sulfur atom 2- thiohydantoin ring second, slower, rate-determining step. rate constants were calculated reactivities towards palladium(II) salts compared discussed. Reaction faster than PdCl2. investigated also react solvent, DMSO-d6, influence these on outcome complexation discussed detail. obtained results this study can have impact explanation behavior antitumor active platinum(II) complexes