Journal of Physical Chemistry B, Vol.103, No.46, 10221-10227, 1999
Solid state voltammetry of an anthraquinone molten salt
The solid-state voltammetries of the two reduction steps of a novel redox polyether hybrid--an anthraquinone molten salt (triethyl(MePEG350)ammonium anthraquinone sulfonate, (Et(3)NMePEG350(+))(AQSO(3)(-)))-and its disulfonated analogue, are reported. Multiple effects on charge transport rates are encountered. Currents for the first reduction step are enhanced by electron self-exchange charge transport, whereas currents for the second reduction wave are greater than 10-fold smaller. The relative charge transport rates of the two reductions are examined as a function of temperature and of incrementally replacing the AQSO(3)(-) anion in the melt with the electroinactive BF4- anion. An analysis that includes ionic conductivity measurements shows that the apparent charge transport rate of the second anthraquinone reduction is attenuated primarily as a result of ionic migration of the products of comproportionation reactions occurring in the diffusion layer.