Attaching poly(ethylene glycol)-mono(methyl ether) (MW 350) chains to [Ru(bpy)(3)](2+) complexes via 4,4'-bipyridine ester linkages produces room temperature, highly viscous, molten salt forms of this well-known complex. This paper describes the synthesis and properties of a series of such complexes bearing two, four, or six polyether chains. Differential scanning calorimetry, rheometry, microelectrode voltammetry, and ac impedance spectroscopy were used to determine the dependence of physical and transport properties of the Ru complex melts on the number of polyether tails. The coupling of electron hopping and physical diffusion in voltammetrically generated mixed-valent layers is analyzed using the Dahms-Ruff relationship, yielding self-exchange rate constants, k(ex), for the Ru(III/II) and Ru(II/I) couples. An activation analysis shows that these reactions are adiabatic, or nearly so, and the slowing of their rates relative to that of the parent [RU(bpy)(3)](2+) complex in fluid solutions is caused by large thermal barriers.