Synthesis of well-defined polythiophene with oxyethylene side chain: Effect of phosphine ligands on catalyst-transfer polycondensation

The effect of phosphine ligand of the Ni catalyst on the polymerization of 2-bromo-5-chloromagnesio-3-[2-(2-methoxyethoxy)ethoxy]-methylthiophene (PMEEMT) was investigated. Threatment of 2-bromo-5-iodo-3-[2-(2-methoxyethoxy)ethoxy]- methylthiophene with equivalent of isopropylmagnesium chloride at 0° C for 1 hour gave magnesium-iodine exchange reaction and the polymerization was carried out by the addition of Ni catalyst to the reaction mixture. The molecular weight increased linearly in proportion to the feed ratio and the molecular weight was controlled by the amount of catalyst. The end groups of PMEEMT were analyzed by matrix-assisted by laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry with dithranol as a matrix in the presence of sodium trifluoroacetate.