Cationic Copper Hydride Clusters Arising from Oxidation of (Ph3P)6Cu6H6

Transfer of the first electron from (Ph3P)(6)Cu6H6 to Cp*Fe-2(+) is fast (k > 10(6) L.mol(-1)s(-1)). Transfer of a second electron to the same oxidant has a much lower thermodynamic driving force and is considerably slower, with k = 9.29(4) X 10(3) L.mol(-1)s(-1). The second oxidation leads to the formation of [(Ph3P)(6)Cu6H5](+). The structure of [(Ph3P)(6)Cu6H5](+) has been confirmed by its conversion back to (Ph3P)(6)Cu6H6 and by microanalysis; X-ray diffraction shows that the complex is a bitetrahedron in the solid state. [(Ph3P)(6)Cu6H5](+) can also be prepared by treating (Ph3P)(6)Cu6H6 with MeOTf. With less than 1 equiv of Cp*Fe-2(+) as oxidant, (Ph3P)(6)Cu6H6 gives [(Ph3P)(7)Cu7H6](+) as the major product; X-ray diffraction shows a Cu-6 octahedron with one face capped by an additional Cu. [(Ph3P)(7)Cu7H6](+) can also be prepared by treating (Ph3P)(6)Cu6H6 with [Cu(CH3CN)(4)](+) (along with 1 equiv of Ph3P), and can be converted back to (Ph3P)(6)Cu6H6 with base/H-2.