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).