Synthesis of dendronized, chiral conjugated polymers with appendant Frechet-type dendrons

New chiral binaphthyl-based polyarylenes [(S)-3a and (S)-3b] with appendant Frechet-type poly(aryl ether,) dendrons (first generation and second generation) were synthesized with Suzuki polycondensation from chiral (S)-6,6'-dibromo-2,2'-didendron-substituted 1,1'-binaphthyl derivatives and p-phenylene diboronic acid. The polymers were studied with circular dichroism, fluorescence, and ultraviolet-visible spectra. Laser light scattering measurements of (S)-3a and (S)-3b showed that their weight-average molecular weights were 2.39 X 10(5) and 1.09 X 10(4), respectively. The specific optical rotation [alpha](D) was -59.6 for (S)-3a and -62.7 for (S)-3b. These dendronized conjugated polymers exhibited good thermal stability. The glass-transition temperatures and the initial decomposition temperatures were 187.5 and 265.3 degreesC for (S)-3a and 173.8 and 308.9 degreesC for (S)-3b, respectively. (S)-3a and (S)-3b had high fluorescence quantum efficiencies, 87 and 91%, respectively, in tetrahydrofuran. (C) 2002 Wiley Periodicals, Inc.