Paramagnetic counter-anions

We have reported evidence of a magnetic interaction in PPy films containing paramagnetic counter-anions [8,10,11]. The magnetic interaction involves the... 

The radical species located on the PPy chains has been studied extensively using EPR spectroscopy [1,39,51,54,80,81] a sharp resonance is usually observed in the g = 2.0 region. The latter originates from a combination of polarons and neutral n-radicals. (This topic has been discussed in detail elsewhere [1]) EPR spectra of PPy containing paramagnetic transition-metal ions exhibit signals originating from the metal ion in addition to the g = 2.Q resonance [6,8,10,11]. Therefore this technique is suited to a study of the nature of the counter-anion and its environment within these materials. 

The observation that the motion of counter-ions can determine the rate of intramolecular ET in weakly polar media is not without a precedent. It has been elegantly demonstrated by the electron paramagnetic resonance (EPR) work of Mazur et al., in which the rate of degenerate electron exchange in radical anions of diketones was studied (17). 

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