導電ポリマーの周りの空間を定義する:カノピーされたポリピロロールの可逆性プロトンドーピング
Dongwhan Lee1, Timothy M Swager
1Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|June 5, 2003
まとめ
新しいピロール誘導体が合成され,高伝導性ポリマーを作成するためにポリマー化されました. その伝導性は,デプロトネーションとレプロトネーションによって正確に調節され,センサーアプリケーションに最適です.
科学分野:
- 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
- オーガニック・エレクトロニクス
背景:
- 導電性ポリマーの開発に際して,インターストランドのpi-piスタッキングを最小限に抑えることが重要です.
- ピロロール誘導体は,機能性ポリマーのための多用途な構成要素です.
研究 の 目的:
- pi-pi スタッキングを制限するために設計された,キャンピーの形状のピロール誘導体を合成するために.
- 結果となるポリマーの伝導性と電子構造を調査する.
- レジスティビティベースのセンシングにおけるこのポリマーの可能性を調査する.
主な方法:
- ステリカルに阻害されたピロール誘導体のアノドポリメリゼーション.
- 電子構造を調査するためのスペクトロ電気化学技術.
- デプロトネーション/レプロトネーションによる伝導性調節の調査.
主要な成果:
- カノピーの形状のピロール誘導体の成功合成 (2).
- アノド性ポリメリゼーションにより,高伝導性ポリマー (poly(2) が得られました.
- 限られた電荷移位が観察され,よく定義された導電性プロファイルが得られました.
- 導電性は,逆転性デプロトネーションと再プロトネーションによって正確に調節された.
結論:
- 設計されたピロール誘導体は,糸間PI-PIのスタッキングを効果的に最小限に抑えます.
- Poly(2) は,高伝導性と感知に適した調節性特性を有しています.
- リバーシブルデプロトネーション/レプロトネーションは,ポリマーの導電性制御のための新しい方法を提供します.
関連する概念動画
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
01:17Pericyclic Reactions: Introduction
Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic rearrangements are...
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic rearrangements are...
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
01:24Types of Reversible Electrodes
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