Formation of quinoid fragments in vacuum-deposited poly-para-phenylene films: IR spectroscopy evidence

Soluble High Molecular Weight Poly(p-phenylene) as a Charge-Transfer Complex

“…New absorption peaks were observed at ∼1560 and ∼1050 cm −1 , caused by the CO and C−C(O)−C bonds in the quinone anion-radical . Other absorption peaks in the IR spectrum of the PPP-TOQ complex were similar to those observed for PPP obtained by Kovacic’s method. , …”

Enzyme and Transition-Metal-Complex Catalyzed Synthesis of Polyphenols with Pendant Oligo(p-phenylene) and Their Optical, Electrochemical, and Thermal Properties

“…The main features of the three spectra are identical: the absorption peak at 3428 cm −1 is due to O−H stretching vibrations; the strong peak at 1484 cm −1 is due to phenyl ring vibrations; and the bands at approximately 820 and 760 cm −1 are due to the out-of-plane C−H bending of p -phenylene and phenyl rings, respectively. The intensities of absorptions due to the out-of-plane C−H bending of the p -phenylene and terminal phenyl rings were used to estimate the degree of polymerization of poly( p -phenylene) . The absorption ratios I 820 / I 760 of PolyPh( m )OHs ( n = 3, 4, and 5) were 0.8, 1.7, and 2.7, respectively; they were largely consistent with the ratio of p -phenylene to phenyl rings in these polymers.…”

“…The intensities of absorptions due to the out-of-plane C-H bending of the p-phenylene and terminal phenyl rings were used to estimate the degree of polymerization of poly(p-phenylene). 19 The absorption ratios I 820 /I 760 of PolyPh(m)OHs (n=3, 4, and 5) were 0.8, 1.7, and 2.7, respectively; they were largely consistent with the ratio of p-phenylene to phenyl rings in these polymers.…”

Morphology-Dependent Optoelectronic Properties of Blue Emitter Poly(p-phenylene) Synthesized with Chemical Vapor Deposition Polymerization

“…The thermal energy supplied by the furnace caused the homolytic bond rupture of the precursor molecules to generate monoradicals and biradicals, which later underwent recombination reactions at the substrate surface to afford the PPP thin films. 16 The inset images of Figure 4 show the appearance of two solutions containing the monomer precursor and PPP fragments excited by a 365 nm UV light. Evidently, there were no visible emissions from the monomer solution, whereas bright blue lights were emitted from the PPP sample.…”

“…A reasonable reaction mechanism is proposed and illustrated in Figure . The thermal energy supplied by the furnace caused the homolytic bond rupture of the precursor molecules to generate monoradicals and biradicals, which later underwent recombination reactions at the substrate surface to afford the PPP thin films . The inset images of Figure show the appearance of two solutions containing the monomer precursor and PPP fragments excited by a 365 nm UV light.…”