Protonation of metal-metal bonds in coordinatively unsaturated diruthenium cores

The addition reaction of a proton towards the coordinatively unsaturated diruthenium complexes [Ru-2(CO)(4)(mu-H)(mu-(PBu2)-Bu-t)(mu-(PP)-P-boolean AND)] (Ru=Ru) ((PP)-P-boolean AND = Ph2PC(=CH2)PPh2, dppen, lb; (PP)-P-boolean AND = Ph2PN(H)PPh2, dppa, 1c; (PP)-P-boolean AND = 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 [Ru-2(CO)(4)(mu-H)(2)(mu-(PEu2)-Eu-t)(mu-(PP)-P-boolean AND)]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. (C) 2012 Elsevier Ltd. All rights reserved.