Synthesis of electronically and coordinatively unsaturated complexes [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-L2)] (L2 = biphosphanes)

A convenient synthesis and the characterization of six new electronically and coordinatively unsaturated complexes of the formula [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-L2)] (2b–g) (RuRu) is described exhibiting a close relation to the known [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (2a). The complexes 2b–g were obtained in a kind of one-pot synthesis starting from [Ru3(CO)12] and PtBu2H in the first step followed by the reaction with the bidentate bridging ligand in the second step. The method was developed for the following bridging ligands (μ-L2): dmpm (2b, dmpm = Me2PCH2PMe2), dcypm (2c, dcypm = Cy2PCH2PCy2), dppen (2d, dppen = Ph2PC(=CH2)PPh2), dpppha (2e, dpppha = Ph2PN(Ph)PPh2), dpppra (2f, dpppra = Ph2PN(Pr)PPh2), and dppbza (2g, dppbza = Ph2PN(CH2Ph)PPh2). The molecular structures of all new complexes 2b−g were determined by X-ray diffraction.

Graphical abstractThe synthesis and X-ray crystal structures of six new coordinatively unsaturated compounds [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-L2)] (2b–g) (RuRu) (L2 = Me2PCH2PMe2, 2b; Cy2PCH2PCy2, 2c; Ph2PC(=CH2)PPh2, 2d; Ph2PN(Ph)PPh2, 2e; Ph2PN(Pr)PPh2, 2f; Ph2PN(CH2Ph)PPh2, 2g) are reported. The investigations showed that these species represent dinuclear metal complexes exhibiting ruthenium–ruthenium double bonds.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A synthesis of phosphanido-bridged diruthenium complexes was developed. ► The method works for a series of bridging biphosphanes as co-ligands. ► The molecular structures of all new compounds were determined by X-ray crystallography.