SYNTHESIS AND MOLECULAR-STRUCTURES OF S2FE2(CO)6 HETEROMETALLIC DERIVATIVES, CONTAINING (PH3P)2PT OR CPRE(CO) FRAGMENTS

The heterometallic cluster (Ph3P)2Pt(mu3-S)2Fe2(CO)6 (II) has been syn thesized by transmetallation of S2Fe3(CO)9 under the action of (Ph3P)2 PtCl2. X-ray studies indicate that II contains a short Fe-Fe bond (mea n 2.496(7) angstrom for 4 independent molecules), but that there are n o bonds between Fe and Pt. It is concluded that transmetallation takes place via a process of coordination of (Ph3P)2PtCl2 with a lone pair of the mu3-S bridge in S2Fe3(CO)9; this is because of the absence of a ny analogous reaction of (PhN)2Fe3(CO)9. The trinuclear cluster CpRe(m u-CO)(mu3-S)2Fe2(CO)6 (III) has been obtained by the interaction of Cp Re(CO)2(THF) with S2Fe2(CO)6. According to X-ray studies this cluster contains short Re-Fe bonds (mean 2.712(2) angstrom), but does not cont ain an Fe-Fe bond. It was concluded that the distinctive features of t he metal-core character of LM(mu3-S)2Fe2(CO)6 clusters depend on the e lectron deficit of the LM fragments.