通过非极性介质中的pi-pi相互作用,在二林三脚-富勒伦超分子复合体中的高效光诱导电子转移
Atsuro Takai1, Mohammed Chkounda, Antoine Eggenspiller
1Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan.
Journal of the American Chemical Society
|March 6, 2010
概括
一种新型的氨酸三脚架,TPZn(3),在氧化后形成分子内pi-dimer,并有效地结合富勒衍生物. 这种超分子复合体使光诱导的电子转移效率高,进步了分子电子和能量转换系统.
科学领域:
- 超分子化学 超分子化学
- 摄影化学的使用.
- 材料科学 材料科学 材料科学
背景情况:
- 氨酸是多功能宏循环,在催化和能量转化中具有应用.
- 开发复杂的氨酸结构对于先进的功能材料至关重要.
- 了解定制分子系统中的电子转移动态,是设计高效器件的关键.
研究的目的:
- 合成和描述一种新的氨酸三脚架,TPZn.
- 研究氧化TPZn的电子和结构性质.
- 使用TPZn(3) 和烯衍生物构建和研究一个超分子供体-接受体系统.
主要方法:
- 通过点击化学合成TPZn(3).
- 电化学分析 (循环电压计).
- 谱学研究 (对NIR,ESR,UV,1H NMR) 进行.
- 激光闪光的光解用于光诱导的电子转移动态.
主要成果:
- TPZn(3) 呈现逐步的单电子氧化,形成由光谱变化指示的分子内部pi-dimer.
- 一个稳定的超分子复合体 (TPZn(3) -PyC(60) 形成了高的关联常数.
- 在TPZn(3) - PyC(60) 复合体中观察到高效的复合体内光诱导电子转移.
结论:
- 在TPZn中,灵活的链接器 (3) 促进了分子内相互作用和超分子复杂化.
- 对于具有高效光诱导电子转移的超分子系统,TPZn(3) 是一个有前途的构建块.
- 这项工作有助于设计用于分子电子和太阳能应用的先进材料.
相关概念视频
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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
Thermal 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.
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The Photochemical Reaction Center
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
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The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
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