D. M. Ivory

Electrical and optical properties of highly conducting charge-transfer complexes of poly(p-phenylene)

Abstract Electrical conductivity, Hall effectm and spectroscopic measurements have been made on AsF 5 -doped poly( p -phenylene). Doping increases the conductivity of the parent polymer by as much as 14 orders of magnitude to values as high as 5 × 10 4 S/m. Hall effect measurements indicate p-type conduction with a Hall mobility approaching 10 −4 m 2 /V s for doping levels between 0.24 and 0.42 moles of AsF 5 per mole of monomer. Doping with an electron donor, K, has increased the conductivity to about 10 3 S/m for a doping level of 0.57 moles of K per mole of monomer. Using this conductivity value, with the assumption of total charge transfer from the donor, suggests a drift mobility for electrons which is significantly less than that for holes. The assumption of an intercalant structure analogous to that of polyacetylene and graphite leads to the conclusion that the presently achieved AsF 5 -doping levels in poly( p -phenylene) correspond to a compound which is not wholly stage 1.

Solid‐state synthesis of highly conducting polyphenylene from crystalline oligomers

Paraphenylene oligomers (biphenyl, p‐terphenyl, p‐quaterphenyl, p‐quinquephenyl, p‐sexiphenyl) form electrically conducting complexes with AsF5. Prolonged exposure to AsF5 causes a polymerization of these p‐phenylene oligomers to give highly conducting charge‐transfer complexes of poly(p‐phenylene). Conductivities as high as 50 S/cm have been measured. Powders, thin films, and single crystals of p‐phenylene oligomers have been reacted with AsF5. The undoped oligomers and the doped, compensated, and annealed products have been investigated by means of x‐ray diffraction, and UV‐visible and IR transmission spectroscopy. The x‐ray diffraction studies give evidence for a change in lattice spacings to those characteristic of the crystalline polymer. The spectroscopic measurements during AsF5 doping reveal shifts in absorption bands in the UV and the IR to those characteristic of poly(p‐phenylene). Paraoligophenylenes have also been reacted with elemental potassium in THF solution with trace amounts of naphthale...

Electrochemical doping of poly-(p-phenylene) with application to organic batteries

The first examples of electrochemical doping of poly-(p-phenylene) to form n- and p-type complexes with counter ions such as Li+ and AsF6– are reported; polyphenylene can be used as the electroactive material in rechargeable battery electrodes.

Highly conducting charge-transfer complexes of a processible polymer: poly(p-phenylene sulphide)

We report the synthesis of highly conducting derivatives of poly(p-phenylene sulphide), the first such organic polymer without a continuous system of overlapping carbon π-orbitals, as well as the first melt-processible polymer which can be doped to high conductivity.

Macromolecular Metals And Semiconductors: A Comparative Study

Highly conducting organic polymers represent a rapidly expanding new research area. As such, fundamental aspects of their electronic and structural properties are not well established and theoretical understanding lags far behind the pace of experimental discoveries.

Highly Conducting Poly(p-Phenylene) Via Solid-State Polymerization of Oligomers

We have discovered a novel method of preparation of highly conductive polymers: the simultaneous solid state polymerization and doping of poly(p-phenylene) oligomers by the action of strong Lewis acids such as AsF5. We have previously shown that higher molecular weight poly(p-phenylene), PPP, can be doped with either strong electron acceptors (AsF5, IF5, HSO3F, SO3, SbCl5) or donors (Na, K, Li) to form highly conducting complexes.2,3 In the present case, we have observed that biphenyl, p-terphenyl, p-quaterphenyl, p-quinquephenyl and p-sexiphenyl polymerize and dope in the presence of AsF5 to form acceptor-doped metallic poly(p-phenylene). We have also observed that the donor dopant, potassium reacts with p-oligophenylenes to form highly conductive complexes, although in this case there is no evidence for increased chain length.

Conducting Complexes of a Processible Polymer: Poly(p-Phenylene Sulfide)

The discovery that polyacetylene, (CH)X, can be doped with electron donors or electron acceptors to yield highly conducting derivatives1 has resulted in a great deal of interest in doped polymer systems and their potential for commercial application as replacements for semiconductors or metals. This interest was heightened by the discovery of two additional conducting polymer systems based on polypyrole2 and poly(p-phenylene) [PPP].3 However, none of these polymers is either melt or solution processible, an important consideration for the majority of potential commercial applications.