The brown residue in the Schlenk flask was successively dissolved in THF, filtered through a column of basic alumina, precipitated once in hexane and 3-4 times in methanol, and then dried overnight under vacuum. The final product was obtained and ready for further analyses. The synthesized polymers were characterized by H NMR spectroscopy (Figures ), gel permeation chromatography (GPC) (Figure ) and powder X-ray diffraction (Figure ).