Platinum-dihalide complexes with N-alkyl O-ethylthiocarbamates

The thiocarbamic esters (L)ETC(EtOSCNHEt) and PTC (EtOSCNHPr) act as sulphur donors towards platinum halides, yielding the cis-[Pt(L)2Cl2], trans-[Pt(L)2Br2], [Pt(L)3X]X (X = Cl or Br) and [Pt(L)4]X2 (X = Cl, Br or I) complexes. By addition of n-hexane to platinum chloride solutions in pure ligands the 1∶6 adducts [Pt(L)4]-Cl2·2L have been isolated. The non-bonded ligand molecules are easily released to give the corresponding 1∶4 complexes. The compounds have been characterized by elemental analysis and spectroscopy. The 1∶4 and 1∶6 complexes decompose in benzene to form the 1∶3 species, except for [Pt(ETC)4]I2, which releases two ligand molecules to give trans-[Pt(ETC)2I2]. The 1∶2 and 1∶3 complexes have been tested for in vitro cytostatic activity against KB cells.