Controlled Synthesis of Polyfluorenes via Kumada Catalyst Transfer Polycondensation with Ni(acac)2/dppp as the Catalyst

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• 作者：Aiguo Sui ; Xincui Shi ; Shupeng Wu ; Hongkun Tian ; Yanhou Geng ; Fosong Wang
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：July 10, 2012
• 年：2012
• 卷：45
• 期：13
• 页码：5436-5443
• 全文大小：426K
• 年卷期：v.45,no.13(July 10, 2012)
• ISSN：1520-5835

文摘

A new catalyst system, i.e., nickel acetylacetonate/1,3-bis(diphenylphosphino)propane (Ni(acac)₂/dppp), was explored to catalyze the Kumada catalyst transfer polycondensation (KCTP) of three fluorene monomers with different substituents at 9-position. The 鈥渓iving鈥?nature of the polymerization was confirmed by polymerization kinetic studies, 鈥渕onomer addition鈥?experiment and block copolymerizations. As a result, poly(9,9-dioctylfluorene)s (PF8s) with the number-average molecular weights (M_ns) in the range 2.8鈥?2.2 kDa and polydispersity indices (PDIs) of 1.20 were successfully synthesized in a controlled manner. The syntheses of fluorene-fluorene and fluorene-thiophene diblock copolymers with M_ns up to 46 kDa were also demonstrated. A complex, i.e. Ni(dppp)(acac)₂, with an octahedral coordination geometry was isolated and confirmed by X-ray crystallographic analysis. The polymerization experiments indicated that the in situ formed Ni(dppp)(acac)₂ should be the active catalyst. To the best of our knowledge, this is the first report on the controlled synthesis of polyfluorenes (PFs) via KCTP.