REACTIONS OF HRUCO3(CO)(9)[HC(PPH(2))(3)] AND H3RU3CO(CO)(9)[HC(PPH(2))(3)] WITH PME(2)PH - CRYSTAL-STRUCTURES OF CLUSTERS HRUCO3(CO)(8)[HC(PPH(2))(3)](PME(2)PH) AND O(CO)(9)[HC(PPH(2))(3)](PME(2)PH)CENTER-DOT-CH2CL2

The reaction of the clusters HRuCo3(CO)(9)[HCCPPh(2))(3)] and H3Ru3Co( CO)(9)[HC(PPh(2))(3)] with the phosphine ligand PMe(2)Ph produces two tetranuclear phosphine-substituted Ru-Co mixed metal clusters. In HRuC o3(CO)(8)[HC(PPh(2))(3)] (PMe(2)Ph) the HC(PPh(2))(3) ligand caps the Co-3 face and the monodentate PMe(2)Ph ligand is coordinated with the Ru atom by replacing one apical carbonyl ligand. In the compound H3Ru3 Co(CO)(9)[HC(PPh(2))(3)](PMe(2)Ph) the tridentate HC(PPh(2))(3) is dis connected from the Ru2Co face and chelates to the Ru atom through two phosphorus atoms while the third phosphorus of the HC(PPh(2))(3) ligan d remains uncoordinated. This leaves one coordination site vacant and the PMe(2)Ph ligand is coordinated without changes in the amount of ca rbonyl ligands.