Reduction of p-terphenyl, p-quaterphenyl and p-sexiphenyl using alkali metal in liquid ammonia: Process and characterization of the reduced compounds

Oligomers of PPP (p-terphenyl, p-quaterphenyl and p-sexiphenyl) were doped using Na or K to promote a reduction. The used method, with liquid ammonia resulted in a solid state doped material without insertion of solvent. The characterization with XPS and Raman spectroscopy showed the formation of at least one phase of the doped oligomer, which contains dianions (bipolarons).