화학공학소재연구정보센터
Macromolecules, Vol.37, No.24, 8978-8983, 2004
Ladder bis-silicon-bridged stilbenes as a new building unit for fluorescent pi-conjugated polymers
pi-Conjugated polymers containing the bis-silicon-bridged stilbene (5,10-dihydro-5,10-disilaindeno[2,1-a]indene) skeleton in the main chain have been synthesized. Our synthesis uses 3,8-dimethoxy derivatives (2) and 3,8-difluoro derivatives (3) of the bis-silicon-bridged stilbene as the key precursors. Thus, their regioselective ortho-metalation reactions with appropriate bases (sec-butyllithium for 2 and (LiBu2ZnTMP)-Bu-t for 3) followed by quenching with electrophiles afford various 2,7-difunctionalized bis-silicon-bridged stilbenes. By using the 2,7-difunctionalized derivatives as starting materials, a series of pi-conjugated polymers, including homopolymers of the bis-silicon-bridged stilbene skeleton and copolymers between the bis-silicon-bridged stilbene unit and other types of monomer units, such as bithiophene and diethynylbenzene, have been synthesized by cross-coupling methodologies. While all the homopolymers of the bis-silicon-bridged stilbene skeleton exhibit an intense blue to greenish-blue emission, the copolymers with the bithiophene and diethynylbenzene units show green and orange emissions, respectively, suggesting easy tuning of the emission colors over a wide range.