Raman studies of intact and sodium doped ¹³C‐substituted poly‐p‐phenylene

The Raman and infrared spectra of ¹³C‐substituted poly‐p‐phenylene (PPP) and the Raman spectra of Na‐doped PPP excited at 488.0 and 1064 nm were observed and compared with the corresponding spectra for the ordinary (¹²C) polymer. ¹³C substitution is shown to be useful for characterizing not only the bands of intact PPP but also those of polarons and bipolarons generated in Na‐doped PPP. The number of Raman bands observed for bioplarons (and also for polarons) is greater than that for intact PPP. This observation is explained as the result of the loss of translational symmetry in the regions of these local excitations.