Polyphenyl

Abstract

A substance indentified as polyphenyl1,2 has been obtained by the condensation of paradichlorobenzene using the Wurtz‐Fittig reaction. The viscosity behavior of polyphenyl is unusual. The curves obtained by plotting specific viscosity divided by concentration versus concentration pass through a maximum at very low concentrations, reaching a constant value at a concentration of about one percent. In the region of the maximum, the specific viscosity divided by the concentration is dependent on the rate of shear, increasing with decreasing rate of shear.

Synthetic Principles for Bandgap Control in Linear π-Conjugated Systems

“…Oligomers of the acene series have been synthesized up to heptacene . Examination of the redox potential and the HOMO−LUMO gap of the first members of the series reveals a sharp decrease of Δ E from naphthalene to heptacene which suggests that increasing chain length could lead to a very small and perhaps vanishing bandgap. , Until now heptacene remains the longest known member of the series and despite several attempts leading to materials of unspecified structure, − the development of a straighforward and unequivocal synthesis of polyacene remains an open question. More recent attempts have been directed toward the synthesis of precursors by means of repetitive Diels−Alder additions, , while the synthesis of polyacene via the cyclization of polybutadiyne has been studied theoretically .…”

Application of “Transfer-Free” Suzuki Coupling Protocols toward the Synthesis of “Unambiguously Linear” Poly(p-phenylenes)

“…Since the overall architecture of the polymer is critically sensitive to any regiochemical flaws introduced during the polymerization, an additional requirement is that the synthesis of genuinely rodlike polymers must occur through an error-free polymerization reaction. Classical methods for the synthesis of poly(arylenes) are inadequate due to the presence of recalcitrant side reactions that both introduce regiochemical irregularities and limit molecular weight. Electrochemical polymerizations do allow for the fabrication of thin films but the molecular weight of the polymer is limited by its insolubility, and regiochemical flaws again appear to be present .…”

Synthesis and Characterization of Some Highly Conjugated Semiconducting Polymers

“…Polyacenes.-An attempt was made at preparation of polyacenes, using a procedure similar to that previously outlined by Edwards and Goldfinger. 41 The reaction involved the condensation of 1,2,4,5-tetrabromobenzene by a Wurtz-Fittig type reaction using Na-K alloy.…”