Protonation of metal–metal bonds in coordinatively unsaturated diruthenium cores

The addition reaction of a proton towards the coordinatively unsaturated diruthenium complexes [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-P^P)] (RuRu) (P^P = Ph2PC(CH2)PPh2, dppen, 1b; P^P = Ph2PN(H)PPh2, dppa, 1c; P^P = Ph2PN(Ph)PPh2, dpppha, 1d) has been investigated. Thus the species 1b–d exhibit a high metal basicity and react with protons from tetrafluoroboric acid in dichloromethane to afford the corresponding oxidative addition products [Ru2(CO)4(μ-H)2(μ-PtBu2)(μ-P^P)]BF4 (2b–d) in good yields. During these reactions a shortening of the metal–metal bond in each case was observed as confirmed by X-ray diffraction studies.

Graphical abstractProtonation reactions of the metal–metal bonds in coordinatively unsaturated diruthenium complexes exhibiting Ru–Ru double bonds were described. During the oxidative addition of a hydrido ligand towards the compounds [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-P^P)] (P^P = Ph2PC(CH2)PPh2, 1b; P^P = Ph2PN(H)PPh2, 1c; P^P = Ph2PN(Ph)PPh2, 1d) the metal–metal bonds were significantly shortened.Figure optionsDownload full-size imageDownload as PowerPoint slide