有機介質におけるハロゲン橋渡しダイルテニウム複合体の制御されたポリメリゼーションと自己組み立て,およびそれらのダイエレクトロフォレティックアラインメント
Rempei Kuwahara1, Shigenori Fujikawa, Keita Kuroiwa
1Department of Chemistry and Biochemistry, Graduate School of Engineering, International Research Center for Molecular Systems (IRCMS), Kyushu University, 744 Moto-oka, Fukuoka 819-0395, Japan.
Journal of the American Chemical Society
|January 10, 2012
まとめ
リポフィルのビュルテニウム複合体は,液晶を形成する協調ポリマーに自己組み立てます. ハロゲンリガンドの種類 (塩化物またはヨウ素) は,ポリマーを決定する.
科学分野:
- 協調化化学について
- マテリアルサイエンス 材料科学
- 超分子化学とは
背景:
- リポフィリックなパドルホイールビュルテニウム複合体は,自己組織化して協調ポリマーになる.
- これらのポリマーの電子的および構造的性質は,ブリッジングリガンドによって影響を受けます.
研究 の 目的:
- ハロゲン・ブリッジビュルテニウムコーディネーションポリマーの自己組み立てと性質を調査する.
- 塩化物とヨウ素の橋渡しリガンドがポリマー構造,熱安定性,電場反応に及ぼす影響を調査する.
主な方法:
- 塩化物またはヨウ素リガンドによるリポフィルビュルテニウム複合体の合成.
- UV-Visスペクトロスコピーと小角X線 difraktionを用いた特徴付け.
- 顕微鏡技術を用いた交流電流 (AC) 電場に対する熱安定性と反応の調査.
主要な成果:
- クロリドブリッジポリマーは,秩序ある柱状六角形相を形成し,ヨウ素ブリッジポリマーは,秩序のない柱状ネマティック相を形成する.
- クロライドブリッジされたポリマーは,最大70°Cまでの優れた熱安定性を示しています.
- 両方のポリマータイプは,電磁場の下では片方向に並び,ヨウ素橋梁ポリマーは,より速く,可逆的な変化を示します.
結論:
- ハロゲン・ブリッジング・リガンドは,ビュルテニウム協調ポリマーの自己組み立てと相行動に大きな影響を及ぼします.
- これらの材料は,制御されたアライナメント特性により,電場反応性ナノ材料としての潜在能力を示しています.
関連する概念動画
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
Formation of Halohydrin from Alkenes
An alkene, such as propene, reacts with bromine in the presence of water to yield a halohydrin. Halohydrins contain a halogen and a hydroxyl group attached to adjacent carbons. When the halogen is bromine, it is called a bromohydrin, while a chlorohydrin has chlorine as the halogen.
Halogenation of Alkenes
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Ziegler–Natta Chain-Growth Polymerization: Overview
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta catalyst, high molecular...
Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...


