Electron transfer from hexameric copper hydrides

The octahedral core of 84-electron LCuH hexamers does not dissociate appreciably in solution, although their hydride ligands undergo rapid intramolecular rearrangement. The single-electron transfer proposed as an initial step in the reaction of these hexamers with certain substrates has been observed by stopped-flow techniques when [(Ph₃P)CuH]₆ is treated with a pyridinium cation. The same radical cation has been prepared by the oxidation of [(Ph₃P)CuH]₆ with Cp* ₂Fe⁺ and its reversible formation observed by cyclic voltammetry; its UV-vis spectrum has been confirmed by spectroelectrochemistry. The 48-electron trimer [(dppbz)CuH]₃ has been prepared by use of the chelating ligand 1,2-bis(diphenylphosphino)benzene (dppbz).