Investigation of doped PPV by NMR and raman scatterring

Summary form only given. In this paper, we present an investigation of PPV doped with Na by combining Resonance Raman Scattering and NMR spectroscopies. The synthesis of PPV has been modified compared to the usual procedure. It has been carried out by a low temperature treatment in the dark (120 /spl deg/C) followed by an UV irradiation at the same temperature in order to improve the polymer in terms of conjugation length and order. Raman spectra have been obtained at different wavelengths for samples doped at various levels and results can be interpreted by using a vibrational model and also in accordance with a previous analysis carried out by Sakamoto et al.(1). Raman results are corroborated by those obtained in NMR. In particular, the modifications observed in the NMR /sup13/C spectra are correlated with the doping level, in consistency with the changes in the electronic structure of the polymer backbone. In the /sup 23/Na NMR spectra, one component is associated with a surface species whereas another is observed at low field, characteristic of the doped state of the polymer.