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Studies on Synthesis, Structure, and Properties of π-Stacked Poly(dibenzofulvene)

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タイトル: Studies on Synthesis, Structure, and Properties of π-Stacked Poly(dibenzofulvene)
その他のタイトル: π-スタック型ポリ(ジベンゾフルベン)の合成、構造および性質に関する研究
著者: Nageh Anwar Mohamed, Hassan 著作を一覧する
発行日: 2018年 9月25日
抄録: Control over spatial arrangement of 1t-electronic groups is an important goal in designing functional polymeric materials because it significantly affects performances of n-electronic polymers and molecular systems exhibiting photo electronic properties such as conduction, emission, optical non-linearity optical, and even photo catalytic activity. Such properties and functions are based on electronic or energetic interactions in the n-conjugated systems, within a molecule and between molecules. It is hence important to design a polymer system so a charge or energy can be transported/transferred smoothly in a regulated way. The most successful and practical examples in this discipline are main-chain conjugated polymers represented by polyacetylene whose conduction has been ascribed to mobility of charged injected by doping through a conjugated chain and among chains. Since the finding of conduction of polyacetylene by Shirakawa, Heeger, and MacDiarmid (The Nobel Prize in Chemistry 2000),2 various main-chain conjugated polymers have been designed and synthesized, among which poly(3,4-ethylenedioxythiophene) (PEDOT) in combination of poly(styrenesulfonate) (PSS) is one of the most industrially applied example. 3 With the excellent conduction behaviors of main-chain conjugated polymers, they have drawbacks including deep color, poor solubility, and chemical fragileness through oxidation. These drawbacks are inherent to the long main-chain conjugation: a narrow HOMO-LUMO levels gap due to the long conjugation allows photoexcitation by visible light, rigidity of the polymer chain arising from limited rotation freedom of bonds that constitute the long main-chain conjugation system promotes inter-chain interactions, and oxidation by 02 in the air deteriorating electronic properties rather easily occurs due to relatively high HOMO levels. These aspects can be overcome through an alternative 1t-electronic macromolecular design, a π-stacked structure. A stack of aromatic groups is an ideal structural motif where charge transport and energy transfer are realized. Piling up multiple aromatic groups without forming covalent bonds among them in an orderly stack in a polymer system may create novel photo electronic polymeric materials free from the shortcomings noted above and even with improved properties. Based on this idea, artificial冗stackedpolymeric and molecular systems have been designed (Figure 1.1); the examples mclude ohgo(m-phenyleneethynylene)s, oligomers consisting of alternating donor and acceptor monomeric Ulllts, 5,6· oligomers consisting of acceptor monomeric units in the main chain that interact with a low­molecular-weight donor molecule, 7 oligomers having perylene moieties in the main chain, 8,9 polymers consisting of cyclophane units, 10-12 a polymer of bezofulvene derivative, 13·14 and polymers of dibenzofulvene (DBF) and its derivatives.15-23 Among these examples, poly(dibenzofulvene) (poly(DBF)) is the first, π-stacked vinyl polymer. In this work, in order to expand and deepen the synthetic and structural aspects of poly(DBF), monomer and polymer syntheses were studied from views that had';never been assessed. In addition, solid-state structure of poly(DBF) was examined for the first time by means of various analytical methods. This thesis summarizes and discusses these aspects and comprises of four chapters. Chapter 1 introduces the background information, Chapter 2 describes a novel method of the synthesis of DBF monomer which is based on photo excited-state chemistry, Chapter 3 discusses the cationic polymerization of DBF which leads to a new π-stacked structure which have been unforeseen in the anionic15·16 and radical18 polymerizations, and Chapter 4 explores into the solid-state structure of poly(DBF) where chain alignments were found.
学位授与機関: 北海道大学
学位の報告番号: 甲第13362号
取得学位の種別: 博士
取得学位の分野: 理学
取得学位の審査委員: (主査) 教授 鈴木 孝紀, 教授 中野 環, 教授 向井 紳, 教授 澤村 正也
学位審査の研究科等: 総合化学院(総合化学専攻)
資料タイプ: theses (doctoral)
出現コレクション:博士 (理学)
総合化学院(Graduate School of Chemical Sciences and Engineering)


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