The catalytic activity of low oxidation state platinum- and palladium-containing mixed-metal clusters

Abstract A series of low oxidation state planar, triangulated clusters containing platinum and palladium, including Pd 2 Mo 2 Cp 2 (CO) 6 L 2 , Pd 2 W 2 Cp 2 (CO) 6 L 2 , Pt 2 Mo 2 Cp 2 (CO) 6 L 2 , Pt 2 W 2 Cp 2 (CO) 6 L 2 and Pd 2 Cr 2 Cp 2 (CO) 6 L2 (where Cp = n-C 5 H 5 and L = PPh 3 or PEt 3 ), the triangular clusters PtCo 2 (CO) 7 (diphos) and PtCo 2 (CO) 7 (diars), the linear trinuclear complexes PtCo 2 (CO) 8 (C 6 HnNC) 2 and PtFe 2 (CO) 6 (NO) 2 (t-BuNC) 2 and the butterfly-shaped cluster Pt 2 Co 2 -(CO) 8 (PPh 3 ) 2 were studied as homogeneous thermal catalysts in the hydrogenation of 1,5-cyclooctadiene, phenylacetylene and 1-hexyne, the oligomerization of butadiene, the hydroformylation of 1-pentene and the hydrosilation of 1-pentene with triethylsilane. Photochemical hydrosilations of 1-pentene and hydrogenations of 1-hexene were also studied. These clusters proved to exhibit moderate activity as catalysts (or catalyst precursors). Some interesting variations in activity with changes in the cluster structure were noted.