Unexpected oxidation of a diphos­phine by bis­(1,3-diphenylpropane-1,3-dionato)­cobalt(II), [Co(dbm)₂]

The reaction of bis­(1,3-diphenylpropane-1,3-dionato)cobalt(II), [Co(dbm)₂], with bis­(diphenyl­phosphino)ethane (dppe) affords the coordination polymer catena-poly[[bis­(1,3-diphenyl­propane-1,3-dionato-κ²O,O′)cobalt(II)]-μ-ethyl­enebis(diphenyl­phosphine oxide)-κ²O:O′], trans-[Co(C₁₅H₁₁O₂)₂(C₂₆H₂₄O₂P₂)]_n, as a result of oxidation of the diphos­phine. The Co atom is octa­hedral, with a CoO₆ coordination sphere, and the chelating dbm ligands adopt a trans configuration. The Co atom also lies on a centre of inversion, with a further symmetry centre bis­ecting the bridging ethyl­enebis(diphenyl­phosphine oxide) ligand.