Reaction of [Os3(μ-H)2(CO)10] with trans-[Pd(NH3)2I2]; molecular structures of [Os6Pd(μ-H)8(CO)18], [Os4Pd(μ-H)4(CO)12(μ-I)2 ], [Os4Pd(μ-H)3(CO)12(μ-I)3 ] and [{Os3Pd(μ-H)3(CO)9(μ-I) }2

Abstract

Reaction of the co-ordinatively unsaturated cluster [Os 3 (µ-H) 2 (CO) 10 ] with trans-[Pd(NH 3 ) 2 I 2 ] afforded the complexes [Os 6 Pd(µ-H) 8 (CO) 18 ] 1, [Os 4 Pd(µ-H) 4 (CO) 12 (µ-I) 2 ] 2, [Os 4 Pd(µ-H) 3 (CO) 12 (µ-I) 3 ] 3 and [Os 3 (CO) 12 ] in moderate yields. Thermolysis of 2 in refluxing chloroform produced 3 and the linked cluster [{Os 3 Pd(µ-H) 3 (CO) 9 (µ-I) } 2 ] 4. Complexes 1–4 were fully characterised by IR and 1 H NMR spectroscopy, mass spectrometry, elemental analysis and X-ray crystallography. The structures of 1 and 2 are based on vertex-shared condensed polyhedra with the palladium atoms at the vertex-sharing sites. The molecular structure of complex 1 consists of a central palladium atom sandwiched between two triosmium units. Complexes 2 and 3 possess a similar metal disposition in which an {Os 3 Pd} tetrahedron bridges to a mononuclear ‘Os(CO) 3 ’ moiety via two and three bridging iodide ligands respectively. Complex 4 is dimeric with two {Os 3 Pd} tetrahedra tied together by two bridging iodide ligands.