A new tris(diphenylstannylene)triosmium carbonyl cluster complex and its reactions with Pt(PBut3)2 and Pt(PPh3)4

The reaction of Os-3(CO)(12) with Ph3SnH yielded the bimetallic Os-Sn cluster complexes OS3(CO)(11)-(SnPh3)(mu-H) (16) and Os-3(CO)(9)(mu-SnPh2)(3) (17) in 20 and 21% yields, respectively. Compound 16 consists of an OS3 triangle with a terminal SnPh3 group on one of the Os atoms and a bridging hydrido ligand across one of the Os-Os bonds. Compound 17 consists of a central Os-3 triangle with SnPh2 groups bridging each of the three Os-Os bonds. Pt(PBu3 iota)(2) reacts with compound 17 to afford Os-3(CO)(9)[Pt(PBu3 iota)](mu-SnPh2)(3) (18), a Pt(PBu3 iota) adduct of 17, in 29% yield by adding a Pt(PBu3 iota) group across one of the Os-Sn bonds. The osmium and tin atoms lie in a plane, while the Pt(PBu3 iota) group is displaced slightly out of that plane. Pt(PPh3)(4) reacts with 17 to give the cluster complex Os-3(CO)(9)[Pt(Ph)(PPh3)(2)]-(mu-SnPh2)(2)(mu(3)-SnPh) (19) in 21% yield by insertion of a Pt(PPh3)(2) into one of the Sn-C bonds to one of the phenyl groups. The osmium and tin atoms are coplanar, and there is a Pt(Ph)(PPh3)2 group terminally bonded to one of the tin atoms. The platinum atom of the Pt(Ph)(PPh3)2 group has a square-planar geometry with the two PPh3 ligands in cis coordination sites. All new products were characterized crystallographically by single-crystal X-ray diffraction techniques.