Pd-2(dppm)(2)X-2 complexes (X=Cl, Br) react with NaBH4 to form [Pd-4(dppm)(4)(mu(4)-H)(2)]X-2 as characterized from chemical analysis, FAB mass, !H and 3!P NMR, and UV-vis spectroscopy, polarography, and conductivity measurements. The dicationic cluster can be reversibly electrochemically catalysis reduced to "Pd-4(dppm)(4)(H)(2)", which is stable at the electrochemical time scale.