ESR and solid state high resolution 13C NMR in AsF5-doped poly para-phenylene

Abstract

Paramagnetic susceptibilities of AsF₅-doped poly(paraphenylene),{C₆H₄(AsF₅)y}_x were observed by the low field Shumacher-Slichter and X-band methods. The results were expressed by the sum of inverse-T (Curie) part and temperature-independent (Pauli) part. The Pauli part gradually appeared from about y~0.05 and finally attained 1.5×10⁻⁶ emu/mo1e-carbon. This is half of that of polyacetylene. The Curie part lineally increased with y up to y˜0.10. This is in contrast to the case of polyacetylene. The Knight shifts corresponding to the susceptibilities were searched by the 13_C CP/MAS high resolution NMR method. The shift was not observed within the experimental accuracy of ±1 ppm.