Reactions of tetrachloroethylene and tetrafluoroethylene with (Ph,P),Pt give the olefin complexes (Ph,P),Pt(olefin). The tetrachloroethylene complex can be isomerised to the vinyl complex (Ph,P),Pt( CCI=CCI,) CI. This isomerisation is solvent-dependent. Trichloroethylene and vans-I ,2-dichloroethylene with (Ph,P),Pt give only the vinyls ( Ph3P),Pt(CH=CC12)CI and (Ph,P),Pt(CH=CHCI)CI, while cis-I 2-dichloroethylene and hexachloropropene give cis-( Ph3P),PtCI2. Reactions of hexachloroethane and chloroform with Pt( PPh,) , give cis-(Ph,P),PtCI,, and bromotrichloromethane gives cis-(Ph,P),PtBr,.Carbon tetrachloride gives a product which is probably (Ph,P),Pt(CCI,)CI.Infrared and n.m.r. spectra of the products are reported.IN a preliminary note1 we reported the formation of a tetrachloroethylene complex of platinum, (Ph,P),Pt(C,Cl,), which results from the reaction of the olefin with tetrakis(triphenylphosphine)platinum(0).2In addition, we found that the reactions of Pt(PPh,), with tetrafluoroethylene, trichloroethylene, and transdichloroethylene gave complexes of stoicheiometry (Ph,P),Pt(olefin). It was suggested that in the complex (Ph,P),Pt (C,Cl,) the olefin formed a three-membered ring with the platinum by way of two a-bonds, as had been proposed for the related olefin complexes formed by tetracyanoethylene,3 tram-stilbene, trans-4,4-dinitrostilbene, and acenaphthylene., The bis( tripheny1phosphine)platinum(o1efin) complexes formed by hexafluoropropene and tetrafluoroethylene were reported at the same time, and the lSF n.m.r. spectra of these complexes suggested that the fluoro-olefins were also bound to the platinum by way of two a-bonds. Recent X-ray studies on the complexes (Ph,P),Ni(C,H,) and (Ph,P),Pt (PhC-CPh) suggests that both the ethylene and diphenylacetylene could be bound to the metal atom in this manner.Olefin complexes of this type have been obtained from reactions of olefins with (i) a bis( tripheny1phosphine)platinum dichloride-hydrazine hydrate r n i ~t u r e , ~ (ii) t e t rakis (t riphen ylphosphine) platinum (0) ,l, (iii) transbis(triethy1phosphine)platinum hydrid~chloride,~ (iv) bis-tripheny1phosphine)platinum (0) ,* (v) a mixture of bis-tripheny1phosphine)platinum oxygen and sodium boroh ~d r i d e , ~ and (vi) other complexes of the type (Ph,P),PtL3 (L = olefin or acetylene).Prior to our work, reactions of tetrachloroethylene with transition-metal complexes had resulted in chlorination of the metal. Thus, reaction of HMn(CO), with the olefin lo gave Mn(CO),Cl, [Mn(CO),Cl],, and Mn,(CO),,; and tmuts-(Et,P),PtHCl and tetrachloroethylene gave t~am-(Et,P),PtCl,.~~ Similarly, reaction of Na+[Mo(CO),(x-C,H,)] with hexachloropropene l2 gave the metal chloro-compound ClMo(CO),(x-C,H,).