[{N(PPh_3)_2}2{Os_18Pd_3(mu_6-C)_2(CO)_42]}: An Osmium-Palladium Mixed-Metal High-Nuclearity Carbonyl Cluster

摘要

High-nuclearity mixed-metal clusters have aroused considerable attentin because of their ability to act as an "electron reservoir", the potential to precisely control the ratio and geometry of the two metals involved,~[1] and their potential application in catalysis.~[2] Reactions of cluster anions with palladium-halide complexes were found to be effective in producing high-nuclearity mixed-metal clusters, for example, [Fe_6Pd_6(CO)_24H]~(3-,[3] [Ru_10Pd_8C_2(CO)_27(C_3H_5)_4],~[4] and [Ni_9Pd_33(PPh_3)_6(CO)_41]~-.[5] However, high-nuclearity os-mium-palladium mixed-metal clusters prepared by a similar approach are rare.~[6] We recently established a reliable route to preparing such species in moderate yield using a deca-osmium cluster anion and a palladium cation as the starting materials. Herein, we report the synthesis and structural characterization of the novel high-nuclearity sandwich osmium-palladium mixed-metal cluster [{N(PPh_3)_2}_2{Os_18Pd_3-(mu_6-C)_2(CO)_42}] (1).