ディスコティック液晶ポリ (プロピレンイミネ) デンドリマーは,トリフェニレン基で作られています
Mark D McKenna1, Joaquín Barberá, Mercedes Marcos
1Química Orgánica, Facultad de Ciencias - ICMA, Universidad de Zaragoza-CSIC, E-50009, Zaragoza, Spain.
Journal of the American Chemical Society
|January 13, 2005
まとめ
トリフェニレン単位を備えた新しいホモデンドリマーは,液晶の性質を示す. 高次の世代は六角柱状の相を形成し,最初の世代は長方形柱状の相を形成し,秩序のある構造を示します.
科学分野:
- 超分子化学 超分子化学
- マテリアルサイエンス 材料科学
- ポリマー化学のポリマー化学について
背景:
- ポリプロピレンイミン (PPI) デンドリマーは,確立されたマクロ分子です.
- ディスコティックトリフェニレン分子は,液体結晶の振る舞いを誘発することが知られている.
- デンドリマーの機能化は,新しい自己組み立て材料につながる可能性があります.
研究 の 目的:
- PPIデンドリマーをトリフェニレン単位で機能化することで,新しいホモデンドリマーを設計・合成する.
- これらの新しいホモデンドリマーの液体結晶の行動とメソフェーズ特性を調査するために.
- 観測されたメソフェーズの構造特性を明らかにする.
主な方法:
- トリフェニレンで機能化されたポリプロピレンイミン (PPI) デンドリマー (G=1-5) の合成.
- 熱分析のための微分スキャニング熱計 (DSC).
- 偏光光学顕微鏡 (POM) でメソフェーズを視覚的に観察する.
- 構造的特徴化のためのX線微分光度測定 (XRD).
- モノ分散性の評価のためのゲル浸透染色学 (GPC).
- MALDI-TOF質量スペクトロメトリーで,機能化を確認する.
主要な成果:
- すべての合成されたホモデンドリマーは,メゾモルフィックな性質を示した.
- 世代G=2-5は,六角形の柱状メソフェーズ (Col(h)) を形成した.
- G=1世代は長方形の柱状メソフェーズ (Col(r)) を形成した.
- X線研究では,分離されたトリフェニレンとデンドリマー列を持つ高度に秩序付けられた構造が確認されました.
- トリフェニレン列の内部で,定期的な積み重ね距離が観察されました.
- GPCはデンドリマーの良好な単分散性を確認しました.
- MALDI-TOFは,末端アミノ基の完全な機能化を確認した.
結論:
- PPIデンドリマーのトリフェニレン部分の機能化により,液晶型ホモデンドリマーは得られます.
- 世代依存の柱状メソファースの行動 (G=2−5,G=1) に対してCol(h),G=1 に対してCol(r) を示した.
- これらのホモデンドリマーには,構成要素の明確な分離を持つ高度に秩序付けられた柱状構造があります.
さらに関連する動画
06:26Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
09:43Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
関連する概念動画
01:16Structure of Conjugated Dienes
Introduction
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[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.
01:21Polymer Classification: Crystallinity
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
01:20Types of Step-Growth Polymers: Polyesters
The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...