Magnetic susceptibility measurements of polycrystalline samples of electrochemically grown [Ru(bpy)(3)](0) show a low-temperature sub-Curie law tail and a broad maximum at about 300 K. The data are consistent with an alternating linear-chain spin-1/2 Heisenberg antiferromagnetic system, with J/k = 238(3) K, the alternation parameter alpha = 0.40(3), and g = 2.20(4). The stronger coupling is probably intermolecular between ligand-localized electrons on adjacent molecules with significant pi* overlap. Four-probe single-crystal conductivities of needle-shaped crystals show the material to be moderately conducting (sigma approximate to 1.5 x 10(-1) Omega(-1) cm(-1) at 297 K) along the long axis. Fittings of the temperature dependence of the conductivity suggest that variable-range three-dimensional hopping is responsible for the observed conductivity.