SYNTHESIS AND CRYSTAL-STRUCTURE OF RU-3(CO)(6)(MU(3)-PPHCH(2)PPH(2))(MU(3)-CYNC)-(CYNC)(2)(PH), AN OPEN TRINUCLEAR CLUSTER COMPLEX CONTAINING AN ISOCYANIDE LIGAND ACTING AS A 4-ELECTRON DONOR

Moderate heating of Ru-3(CO)(10)(dppm) with CyNC (1:3) for 2 h under nitrogen, 68 degrees C and purification by TLC affords moderate yield of the yellow complex Ru-3(CO)(6)(mu(3)-PPhCH(2)PPh(2))(mu(3)-CyNC)(CyNC)(2)(Ph) (1), which has been shown by X-ray crystallography to contain an open Ru-3 cluster with one isocyanide ligand acting as a 4e donor and bonded to all three metal atoms, representing a novel type of bonding of isocyanide on a Ru-3 cluster. Another interesting feature of 1 is the trapping on the cluster of the phenyl group lost from the dppm ligand.