Synthesis of regiocontrolled poly(4,6-di-n-butoxy-1,3-phenylene) by oxidative coupling polymerization

Poly(4,6-di-n-butoxy-1,3-phenylene) (6) was prepared by oxidative coupling polymerization of 1,3-di-n-butoxybenzene (1) or 2,2',4,4'-tetra-n-butoxy biphenyl (3). Polymerizations were conducted in nitrobenzene in the presence of FeCl3 at room temperature and produced polymers with number-average molecular weights up to 42,000. The effects of various factors, such as amount of FeCl3 and reaction temperature and time were studied. The structure of polymer 6 was characterized by 270 MHz H-1- and 68.5 MHz C-13-NMR spectroscopies and was estimated to consist of almost completely 1,3-linkage. The regiocontrolled polymer was readily soluble in common organic solvents. Thermogravimetric analysis of polymer 6 showed 10% weight loss at 390 degrees C in nitrogen. (C) 1997 John Wiley & Sons, Inc.