Mechanistic studies on the polymerization of R,R′-dibromo-2-methoxy-5-(2-ethylhexyloxy)xylene have been performed. Polymerizations were initially carried out by adding potassium tert-butoxide to monomer in the presence of a chain transfer agent, anthracene. Anthracene showed little effect on the molecular weight of the resulting polymer, suggesting that the major polymerization route was not radically initiated. Polymerizations were also carried out by adding monomer to potassium tert-butoxide in the presence of a nucleophile, 4-methoxyphenol. The molecular weight of the resulting polymer scaled linearly with the amount of 4-methoxyphenol, suggesting an anionic mechanism. In addition, each polymerization was monitored by in-situ torque measurements to further elucidate the polymerization mechanism and optimize polymerization conditions.

We present time-of-flight mobility measurements and measured and calculated current–voltage (I–V) characteristics of structures fabricated using a soluble poly(p-phenylene vinylene) derivative. Time-of-flight measurements were used to determine the electric field dependent hole mobility. This mobility was then used, without adjustable parameters, to calculate the I–V characteristics of space-charge-limited, hole only devices. The measured and calculated I–V characteristics are in good agreement over five orders of magnitude in current. These results demonstrate that an electric field dependent mobility, without invoking trapping effects, provides an accurate description of hole transport in this polymer.

We present capacitance–voltage and current–voltage measurements of polymer light-emitting electrochemical cells and compare these results with steady state device model calculations. The capacitance–voltage characteristic is used to assess the formation and structure of the electrochemical junction in the device. The cell capacitance and current both increase sharply above a threshold voltage as the bias is increased. The threshold voltage for the rapid increase in capacitance is lower than that for the increase in current, indicating that the electrochemical junction begins to form prior to significant current flow. The electrochemical junction width, estimated from the capacitance measurements, is about 15 nm at a current density of 0.1 A/cm2. The steady state device model calculations are in reasonable agreement with these observations.

SYNOPSISA series of fluorinated aromatic polyethers was synthesized via aromatic nucleophilic substitution of highly fluorinated aromatics ( 1,2,4,5-tetrafluorobenzene, hexafluorobenzene, and decafluorobiphenyl) with bisphenol AF or bisphenol A. Polymerization with 1,2,4,5tetrafluorobenzene was not observed, and polymerization of hexafluorobenzene with bisphenol proceeded only if the potassium carbonate-bisphenol ratio was carefully controlled.The polymer condensed from decafluorobiphenyl and bisphenol AF was prepared in 77% yield with an inherent viscosity of 1.01 dL/g. The polymer prepared from the condensation of decafluorobiphenyl with bisphenol A was obtained in 48% yield with an inherent viscosity of 0.28 dL/g. These polymers were very soluble in common organic solvents, formed clear, colorless films, and were thermally stable (> 450°C by TGA). The fully fluorinated polymer exhibited low water uptake (0.3% ) and dielectric constant (2.17). 0

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