RESUMO
To clarify the mechanism of thermal dedoping processes of conducting poly(3-alkylthiophenes), temporal changes in electric conductivity, photoabsorption, and electron spin resonance of iodine-doped poly(3-octylthiophene) were examined. A decrease in the electric conductivity was accompanied by a decrease in the photoabsorption of the polymer cation and an increase in the spin concentration: the cation is a spinless charge carrier and it was converted to an immobile paramagnetic species. The conversion proceeds through deprotonation of the cation, which results in the formation of a polyenyl radical.
RESUMO
Chain reactions in gamma-irradiated 2-propanol solutions of diphenyliodonium salts have been studied. Protonic acids were generated in the irradiated solutions with high yields, whereas acid formation as a result of thermal reactions was negligible. The solution can be used as a high-sensitivity chemical dosimeter. The G value of acidic protons increases with increasing concentration of diphenyliodonium salt at the lower concentrations because the reaction rate of a propagation reaction increases. However, the chain is limited by a termination reaction between phenyl radical and the iodonium salt: The G value shows a maximum value of 610 micromol J(-1) at the concentration of 0.08 mol dm(-3) and decreases at higher salt concentrations.
