Electrosyntheses Of Hight Quality Polyselenophene, Polyfluoranthene And Halogen Substituted Polyindole Derivatives

Electrochemical polymerization had been proved to be one of the most useful approaches for conducting polymer synthesis with several advantages. This dissertation focused on the electrosyntheses and the characterizations of high-quality conducting polymers in pure boron trifluoride diethyl etherate (BFEE), such as polyselenophene, polyfluoranthene, poly (5-fuoroindole), poly (5-chloroindole) and poly (5-bromoindole). The interactions between the middle strong Lewis acid, BFEE, and the aromatic monomers lower their oxidation potentials, which facilitates the formation of high quality polymer films.1. High-quality free-standing polyselenophene films with conductivity of 2.8×10^-1 S cm^-1 were synthesized electrochemically by direct oxidation of selenophene in pure BFEE for the first time. The oxidation potential of selenophene in this medium was measured to be only 1.23 V vs. SCE, which was much lower than that in acetonitrile + 0.1 BU4NBF4 (1.83 V vs. SCE). PSe has better thermal stability than polythiophene, wich can be inferred that the more polarizable and larger selenium atom presents a notable effect on increasing the thermal stability.2. High-quality polyfluoranthene films with electrical conductivity of 10^-2 S cm^-1, were synthesized electrochemically by direct anodic oxidation of fluoranthene in BFEE for the first time. Polyfluoranthene films obtained from this medium showed good redox activity and stability even in concentrated sulfuric acid. The polymer synthesized in this medium was partially soluble in polar organic solvents. The soluble part of polymer had a strong fluorescence. Quantum chemistry calculations and ¹H NMR spectra showed that the polymer chains were grown via the coupling of the monomer at C₃, C₄, C₁₃, C₁₄ positions.