VOLTAMMETRY AND CONDUCTIVITY OF A POLYETHER-PYRIDINIUM ROOM-TEMPERATURE MOLTEN-SALT ELECTROLYTE AND OF ITS POLYMER ELECTROLYTE-SOLUTIONS INPOLYDIMETHYLSILOXANE

This report describes the synthesis, microelectrode voltammetry, and i onic conductivity of a new room temperature molten salt N-(methoxy(eth oxy)(2)ethyl)pyridinium p-toluenesulfonate (abbreviated as [Py(E(3)M)( +)][Tos(-)]) and of its solution in a hydroxy-terminated polydimethyls iloxane. Both ionically conductive liquids (conductivity = 1 X 10(-4) Omega(-1) cm(-1)) exhibit voltammetric potential windows of about 1.5 V:The negative potential limit is determined by the reduction of the [ Py(E(3)M)(+)] pyridinium species, with subsequent radical coupling to form a voltammetrically observed viologen dimer. The estimated diffusi vities of the [Py(E(3)M)(+)] species, of a diethyleneglycol-tailed fer rocene redox solute studied, and by application of Nernst-Einstein rel ation to the ionic charge carriers, ail lie in the 10(-7) to 10(-8) cm (2)/s range. Viscosities and glass transition thermal observations are reported as is the fit of the temperature dependencies of ionic condu ctivity in [Py(E(3)M)(+)][Tos(-)] and in [Py(E(3)M)(+)] [Tos(-)]/PDMS mixtures to Vogel-Tamman-Fulcher predictions.