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Dopant uptake in sodium-doped poly( p -phenylene vinylene) (PPV) has been measured, and e.s.r. spectroscopy has been used to follow the changes in unpaired spin concentration as the doping reaction proceeds. 2 H n.m.r. line shapes of sodium-doped, ring-deuterated PPV (PPV-d 4 ) have also been studied to observe the effects of doping. They contain two distinct components, one of which is attributed to hydride formation. The overall pattern is insensitive to temperature changes.

Ring-deuterated poly( p -phenylene vinylene) has been doped with concentrated sulphuric acid and examined with 2 H quadrupole echo nuclear magnetic resonance spectroscopy. Doping is observed to change the relative population of fast versus slow flipping p -phenylene rings. This relationship has been investigated over a range of temperatures. Modelling this system as a two-site chemical exchange shows that the change in the relative populations of fast versus slow ‘flippers’ corresponds to an increase in the activation energy for the 180° ring flip. The width of the distribution of flip rates is also observed to increase upon doping. At elevated temperatures the samples studied undergo a significant loss of mass which corresponds to a loss of dopant. The chemistry of this process is examined.