Precise Preparation of Stacked Organosilicon Polymers using Metal Catalysts and Their Chemical Properties

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05789
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Polymer chemistry
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Tanabe Makoto 東京工業大学, 科学技術創成研究院, 特任准教授 (80376962)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ケイ素 / 共役高分子 / ニッケル / 白金 / 積層構造 / 脱水素 / シロール / 解重合

Outline of Final Research Achievements

Dehydrocoupling polymerization of 1,1-Dihydrodibenzosilole (DBSH2) and 4,4-dihydrodithienosilole (DTSH2) as monomers is expected to give polysilanes which are composed of a silicon backbone with π stacking delocalization along the main chain.
The Ni-catalyzed polymerization of DBSH2 afforded the polysilanes with a narrow polydispersity. Treatment of the tetramer in the same Ni catalysts resulted in the initial formation of a mixture of monomers and trimers, which subsequently transformed into oligomers. This polymerization involves a preferential dehydrogenative condensation, while the presence of H2 regenerates the monomer after its consumption and thus promotes further polymer growth. DTSH2 undergoes unexpected cyclodimerization accompanied by skeletal rearrangement to afford a cis-fused bicyclic compound in the presence of a similar Ni catalyst. We succeeded in isolating DBSH2 and DTSH2 monomers and discovered the preciously controlled dehydrogentaive polymerization.

Free Research Field

高分子化学，有機金属化学

Academic Significance and Societal Importance of the Research Achievements

π共役導電性高分子は二次電池，発光材料などの電子材料として幅広く応用研究が展開されているが，高分子鎖の剛直さから溶解性が低いなどの問題がある．本研究では，有機ケイ素高分子の構造と高分子鎖の柔軟性に着目して，側鎖置換基が一次元方向に積層した高分子の設計・重合を達成した成果である．これは柔軟な共役高分子の発見として学術的な意義は大きい．従来，有機ケイ素高分子の合成法は限られており，金属錯体を用いて分子量制御が可能な重合法を開発したことも重要な意義がある．本課題では重合開発に重点を置いたが，積層型共役高分子の光導電性材料などの応用研究も展開できる。