In recent years, soluble derivatives of CuH prepared by non-aqueous routes have become important as mild reducing agents, one such compound, Stryker¿s reagent [Ph3PCuI]6. The complex consists of an octahedron of copper atoms, each with an attached triarylphosphine and with six of the eight triangular faces capped by a triply-bridging hydride. The principal aim of this proposal is to determine the modes associated with the bridging hydrides. This will be the first characterisation of triply bridging hydrides on copper and will inform the debate as to the adsorption site of hydrogen on Cu(111). To accomplish these aims we will prepare selectively deuterated compounds. All of the reactants, including the deuterated species are available from Aldrich and the Bangor team have considerable expertise in the synthesis of air-sensitive organometallic compounds