ORGANOPLATINUM(II) COMPLEXES CONTAINING DISUBSTITUTED DITHIOXAMIDES -EVIDENCE FOR AN S,S' PT COORDINATED NEUTRAL DITHIOXAMIDE ACTING AS ANANION-BINDING AGENT

cis-[PtI(2)R(2)] (L = Me(2)SO or Me(2)S; R = Me or Ph) species react w ith N,N'-disubstituted dithioxamides H-2-R'(2)-DTO (R' = methyl, benzy l, n-butyl) leading to a new class of organoplatinum compounds of gene ral formula [PtL(R)(H-R'(2)-DTO)] (1). These are the first reported or ganometallic complexes containing an S,S' Pt chelated rubeanate. The n ew compounds react with some neutral ligands L' (L' = carbon monoxide, phosphines and thioureas) giving [PtL'(R)(H-R'(2)-DTO)] (2) products, which are totally unreactive toward nitrogen bases such as amines, py ridines and anilines. The compound trans-[Pt(Me(2)SO)(2)MeCl] reacts w ith H-2-bz(2)-DTO forming the contact ion pair {Pt(Me(2)SO)Me(H-2-bz(2 )-DTO)(+),(Cl-)} (3); this is a non-isolable species since the Pt-CH3 bond is cleaved by acidic hydrogens of the coordinated neutral dithiox amide leading to the formation of methane and [Pt(Me(2)SO)Cl(H-bz(2)-D TO)] (4). A structure for the tight ion pair {Pt(Me(2)SO)Me(H-2-bz(2)- DTO)(+),(Cl-)} is proposed in which the coordinated neutral dithioxami de acts as an anion binding agent.