Dinuclear Ruthenium and Iron Complexes Containing Palladium and Platinum with Tri-<i>tert</i>-Butylphosphine Ligands: Synthesis, Structures, and Bonding

The reaction of Pd(PBut3)2 with Ru(CO)5 yielded the dipalladium−diruthenium cluster complex Ru2(CO)9[Pd(PBut3)]2,
10. The reaction of Pt(PBut3)2 with Ru(CO)5 at room temperature afforded the diplatinum−diruthenium cluster complex
Ru2(CO)9[Pt(PBut3)]2, 12, and the monoplatinum−diruthenium cluster PtRu2(CO)9(PBut3), 11. All three complexes
contain a diruthenium group with bridging Pd(PBut3) or Pt(PBut3) groups. Compound 11 can be converted to 12 by
reaction with an additional quantity of Pt(PBut3)2. The reaction of 12 with hydrogen at 68 °C yielded the dihydrido
complex Pt2Ru2(CO)8(PBut3)2(μ-H)2, 13. This complex contains a Ru2Pt2 cluster with hydride ligands bridging two
of the Ru−Pt bonds. The reaction of Fe2(CO)9 with Pt(PBut3)2 yielded the platinum−diiron cluster complex
PtFe2(CO)9(PBut3), 14, which is analogous to 11. All new complexes were characterized crystallographically. Molecular
orbital calculations of 10 reveal an unusual delocalized metal−metal bonding system involving the Pd(PBut3) groups
and the Ru2(CO)9 group.