SYNTHESIS AND STRUCTURE OF PLATINUM (II) COMPLEXES WITH DECOMPOSITION PRODUCT OF DITHIODIETHYLAMINE βMERCAPTOETHYLAMINE

Abstract

The interaction of dithiodiethylamine (cystamine) (L1 ) with Pt(II) in aqueous medium was studied and it showed that in aqueous solutions in an acidic medium, the disulfide bond L1 was cleaved, followed by coordination of platinum to form β-mercaptoethylamine (mercamine, LH). Depending upon the reaction conditions, binuclear complexes of composition µ(S)[Рt2(LН)2С14](I), µ(Cl)[Рt2(LН)2С14](II) with bridging chlorine or sulfur atoms were formed. At 70°С, a compound with a bridged position of sulfur atoms (complex I), and at lower temperatures (30-500 ) with a bridged position of chlorine atoms (complex II) were formed. X-ray structural analysis of the complex [Рt2(LН)2С14] (I) was carried out. Crystals I are rhombic, with 20°Са = 17.282(1), b = 9.986(1), с = 8.0188(9) Å;R = 0.029. Molecule I is a binuclear complex in which platinum atoms are linked by a pair of bridging thiolate ligands (-SСН2-СН2-МН3 + ). The Pt2S2 metallocycleis are bent along the sulfur-sulfur line, so that the dihedral angle between the coordination planes of platinum atoms is equal to 138°. The S–S distance, equal to 2.909(1) Å, is noticeably shorter than the doubled van der Waals radius of the sulfur atom (3.60 Å). The structure of the complexes was also confirmed by IR spectroscopy data.