Powder X-ray diffraction (PXRD) patterns of 1 and 2 display several sharp reflection peaks at 2θ values of 5-30°. However, CP1-CP2 are amorphous, as revealed by broad peak in the range of 20° to 25° in the PXRD pattern (Figure ). The Brunauer-Emmett-Teller (BET) surface areas for CP1 and CP2 were determined to be 24.1 and 41.3 m 2 /g, respectively (Figure ). Such small surface area was tentatively attributed to the strong stacking as a result of the largely linear and extended conjugated system. Thermogravimetric analysis (TGA, Figure ) of the as-prepared polymers under N2 unveils modest-to-high thermal stability. The decomposition temperatures (defined as the temperatures of 5% mass loss) were determined to be ca. 150 °C. while those of 1 and 2 are 0.25 and 0.05 mg mL -1 , respectively. These results validate our design concept that the stronger intermolecular interaction (π-π stacking) can reduce the overall solubility, even for relatively small molecules. Polymerization further suppresses the solubility and two polymers (CP1 and CP2) gratifyingly exhibit undetectable solubility. On the other hand, as shown in Figure , the conductivity measurement confirms that the electrical conductivity of 2 (8.9  10 -8 S cm -1 ) is slightly higher than that of 1 (6.2  10 -8 S cm -1 ), consistent with the D-A design that leads to relatively stronger intramolecular charge transfer.