Thin films of a novel Ru-phenolate based metallopolymer, [RU(terpy)(box)PVP20]PF6, in which one in every twenty of the 4-vinyl pyridine monomer units is labelled with the ruthenium complex have been formed on glassy carbon electrodes, terpy is 2,2':6',2 ''-terpyridine, box is 2-(2-hydroxyphenyl)benzoxazole, and PVP is poly(4-vinylpyridine). Cyclic voltammetry and Raman spectroscopy reveal that the Ru2+/3+ couple is electrochemically reversible but that the phenolate ligand based oxidation is irreversible. These redox processes are associated with reversible colour changes from wine red (reduced) to red orange (mixed composition) then to light green (oxidized) in the visible region and an irreversible change in the near-IR region, respectively. Scanning electron microscopy reveals that repeated switching in LiClO4 aqueous solution does not induce any significant structural change within the deposit films. Cyclic voltammetry has been used to determine the electrochromic switching rate under semi-infinite linear diffusion conditions. In aqueous LiClO4, the homogeneous charge transport diffusion coefficient, D-CT, decreases from 3.6 +/- 0.3. 10(-13) to 2.7 +/- 0.2 x 10(-13) cm(2) s(-1) as the LiClO4 concentration increases from 0.1 to 1.0 M. This weak dependence of D-CT on electrolyte concentration suggests that counterion availability is not rate-determining and that the overall Fate of charge transport through the metallopolymer film is limited by the rate of segmental polymer chain motion necessary to bring adjacent centres Sufficiently close to allow electron transfer to Occur Also the impact of changing the identity of the charge compensating anion of the redox electrochromic switching rate has been investigated. Finally, the electronic conductivity has been determined using interdigitated array electrodes (IDAs). (C) 2008 Published by Elsevier Ltd.