氨酸盒是由同体性自排序组件构建的:光学分离,刺激合和高效的刺激能量迁移
In-Wook Hwang1, Taisuke Kamada, Tae Kyu Ahn
1Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
Journal of the American Chemical Society
|December 9, 2004
概括
自组装的 (II) 氨酸盒 (Bn) 通过同体性自排序形成. 这些结构促进了高效的激发能量迁移,模仿了自然光采集复合体.
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:
- 介质皮里丁附加的 (II) (Mn) 和它们的二极体 (Dn) 自组装.
- 在非协调的溶剂中,四度氨酸方形 (Sn) 和盒子 (Bn) 自发形成.
研究的目的:
- 调查氨酸盒 (Bn) 的同体性自我分类组件.
- 描述这些自组装结构内的激发能量迁移.
- 使用氨酸盒模拟采光复合体.
主要方法:
- 光学分离和循环二元化 (CD) 光谱学.
- 五秒秒短暂吸收光谱学.
- 极化异构度测量和福斯特式能量跳跃模型.
主要成果:
- 证实了氨酸盒 (Bn) 的同人体自我分类组装.
- 在Bn.内观察到刺激合和能量迁移.
- 对B1,B2和B3的激发能量跳跃率被量化.
结论:
- 自组装的氨酸盒 (Bn) 提供了一个明确的3D模型系统.
- 这些结构有效地模仿了自然光采集综合体的功能.
- 这项研究阐明了人工光合作用系统中的能量转移机制.
相关概念视频
Photosystem I
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
The Antenna Complex
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
The Z-Scheme of Electron Transport in Photosynthesis
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
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.
Photochemical 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


