Iodine-doped Poly Research Articles

Highly conducting iodine-doped poly(copper-yne) from phenylacetylene

Poly(phenylethynylcopper) (PPECu) was synthesized by reaction of the corresponding acetylenic compound with cuprous iodide. Chemical analysis yielded a composition (C 6H 5CCu) n . Infrared, Raman and ultraviolet spectroscopy showed that PPECu is a coordination polymer having substantial back coordination from the filled metal d-orbitals to the antibonding orbitals of the acetylene groups. PPECu is a good insulator. On doping with iodine, the d.c. conductivity of PPECu is enhanced by about 13 orders of magnitude (σ d.c. = 14 Ω −1 cm −1 at 300 K) . The conductivity slightly decreases with increasing temperature. The thermopower is small ( S = +4 μV K −1) and nearly temperature independent. Based on electron impact, i.r. and u.v. spectroscopy it is concluded that charge-transfer complexes are formed between phenylethynylcopper and iodine. The conduction mechanism of iodine-doped PPECu can be understood in the framework of the theory that describes electrical conduction in quasi-one-dimensional mixed-valence stacked complexes.

Vibrational Spectroscopy of Iodine-Doped Poly(Phenyl)Acetylene

The complementation of Resonance Raman, Raman Polarization data, and far infrared spectroscopy was used to determine the nature of the iodine moiety in iodine-doped poly(phenyl)acetylene. For the molar concentration range of iodine/polymer of 1 to 5, the predominant iodine entity in the iodine-doped conductive polymer appears to be I5-.