SYNTHESIS AND STRUCTURE OF PLATINUM(ii) COMPLEXES WITH DITHIODIETHYLAMINE

Abstract

The interaction of dithiodiethylamine (cystamine) (L1) with platinum compounds in non-aqueous and aqueous media has been studied. It is shown that in aqueous solutions, the L1 disulfide bond is cleaved, followed by platinum coordination of the resulting β-mercaptoethylamine (mercamine, HL). Depending on the reaction conditions, binuclear complexes of the composition [Pt2(LH)2C14] with bridged chlorine or sulfur atoms or [Pt2L2C12] with bridged chlorine atoms are formed. An X-ray diffraction analysis of the [Pt2(LH)2C14] (I) complex was carried out. Crystals I are rhombic, at 20 °C a=17.283(1), b=9.987(1), c=8.0187(9) Å; R=0.030. Molecule I is a binuclear complex in which platinum atoms are united by a pair of bridged thiolate ligands (-SCH2-CH2-NH+3). The metallocycle Pt2S2 is bent along the sulfursulfur line, so that the dihedral angle between the coordination planes of platinum atoms is 138°. The S-S distance equal to 2.909(1) Å is noticeably shorter than the doubled van- der- vaals radius of the sulfur atom (3.60 Å). The implementation of the reaction in benzene makes it possible to obtain a complex (L1H2)[PtX4] (X=C1, Вг) with the preservation of the sulfur-sulfur bond in the ligand. The structure of the complexes is confirmed by IR spectroscopy data.