Cluster synthesis 44. The synthesis and structural characterization of an unusual new high nuclearity platinum-osmium cluster complex,Pt5Os6(CO)25

The reaction of Pt₂Os₄(CO)₁₈ (1) with H₂ in refluxing octane (125°C) yielded the new compound Pt₅Os₆(CO)₂₅ (2), 58%. Compound 2 was characterized by IR, elemental and single crystal X-ray diffraction analyses. Compound 2 contains 11 metal atoms. five platinum, and six osmium. The cluster can be viewed as two fused trigonal bipyramidal clusters that share one platinum vertex. These two clusters are also joined by three metal-metal bonds, and Os(CO)₄ groups bridge two of these three metal-metal bonds. Crystal data for 2·CH₂Cl₂: space group itP1¯ma=12.250(1) Å,b=17.476(4) Å,c=11.89(2) Å,=109.87(1)°,=112.66(1)°,=83.05(2)°,Z=2, 2986 reflections,R=0.033.