화학공학소재연구정보센터
Polymer, Vol.170, 204-210, 2019
Synthesis of reactively functionalized 2,5-siloles using kumada-type nickel-mediated intramolecular cyclization and their utilization in polymer synthesis
The syntheses of reactively functionalized 2,5-siloles by the Kumada-type nickel-catalyzed intramolecular cyclization of alkynes and disilane, and their subsequent polymerization with diketopyrrolopyrrole (DPP) are described. The prefunctionalization of the 2,5-positions of the silole ring, which avoids the problem of silole susceptibility to nucleophiles during post-modification highlights this synthesis. Suzuki, Stille, and direct arylation silole precursors were prepared by this reaction and were subsequently subjected to polymerization with DPP by the various polymerization methods. The polymers all had reduced bandgaps (E-g < 2 eV). A lower E-g was observed for the 2,5-dithienylsilole polymers (P2 and P3) compared to the 2,5-diphenylsilole polymers (P1 and P4) highlighting the effect of thiophene - silole orbital overlap on the E-g. While the direct arylation reaction resulted in the desilylation of the silole moiety of P5 causing a hypsochromic shift in the absorption wavelength compared to P1-P4, a similar E-g to the 2,5-diphenylsilole polymers was observed.