Ru4(μ-CO)(CO)9(η4-μ4-C6H4)(η2-μ1,μ4-PPhCH2CH2PPh2): an unusual pyrolysis product of Ru3(CO)10(dppe) containing a benzyne ligand

The thermal decomposition of Ru3(CO)10(dppe) in refluxing benzene gives, in contrast to the pyrolysis of the dppm analogue, the tetranuclear cluster Ru4(μ-CO)(CO)9(η4-μ4-C6H4)(η2-μ1,μ4-PCH2CH2PPh2) (1) along with Ru3(CO)9(η2-μ1,μ2-C6H5)(η3-μ1,μ2-PPhCH2CH2PPh2) (2). The single-crystal structure analysis of 1 reveals a square-planar tetraruthenium skeleton containing a η4-μ4-benzyne ligand as well as a η2-μ1,μ4-phosphinidene–phosphine ligand.