Synthesis and characterization of polyacenic complexes

Polyacenic materials, or polyacenes (PAS) in short, prepared from pyrolysis of phenolic formaldehyde were doped with halogen and organic accepters. The charge transfer interactions between PAS and various dopants are examined by means of X-ray photoelectron spectroscopy (XPS). It was shown that I-3(-) was the main form of anion in the iodine-doped PAS. However, for bromine and chlorine doped PAS, halogen anion (Br-,Cl-) and covalently bonded halogen (C-Br and C-Cl) co-existed. Charge transfer interactions were also observed between PAS and various organic accepters, such as 2,3 dichloro-5,6 dicyano-p-benzoquinone (DDQ), tetracyanoethylene (TCNE) and o-chloranil. The interactions with o-chloranil involved the formation of chlorine anions.