Combining two coordinatively unsaturated diruthenium cores by the tetradentate ligand (Ph2P)2NCH2C6H4CH2N(PPh2)2

The tetradentate N,N-bis(diphenylphosphanyl)amine ligand (Ph2P)2NCH2C6H4CH2N(PPh2)2 (1, xdppa) reacted with in situ prepared [Ru2(μ-H)(μ-PBut2)(PBut2H)2(CO)4] (2) in a molar ratio of 1:2 affording the novel twofold coordinatively unsaturated tetranuclear metal complex [Ru2(μ-H)(μ-PBut2)(CO)4(μ-xdppa)Ru2(μ-H)(μ-PBut2)(CO)4] (3). Compound 3 was protonated by tetrafluoroboric acid at each side of the unsaturated diruthenium frameworks affording the oxidative addition product [Ru2(μ-H)2(μ-PBut2)(CO)4(μ-xdppa)Ru2(μ-H)2(μ-PBut2)(CO)4](BF4)2 (4). All new compounds were characterized by spectroscopic means and the molecular structures of compounds 1 and 4 were determined by X-ray diffraction.