通过叶绿素20位的分子内部电子转移衍生物:一种意想不到的有效的电荷传输管道
Richard F Kelley1, Michael J Tauber, Michael R Wasielewski
1Department of Chemistry and International Institute of Nanotechnology, Northwestern University, Evanston, Illinois 60208-3113, USA.
Journal of the American Chemical Society
|April 6, 2006
概括
新的叶绿素a衍生物 (ZCPh) 在供体-接受体双中进行了合成和研究. 尽管有结构上的差异,ZCPh和氨酸二由于电荷再分配而表现出类似的电子转移速率.
科学领域:
- 摄影化学的使用.
- 有机合成 有机合成
- 频谱学是一种光谱学.
背景情况:
- 叶绿素和衍生物对于理解光采集和电子转移过程至关重要.
- 供体-接受体二极管是研究光诱导电荷分离和重组的模型系统.
- 宏观循环捐赠体的电子和结构性质影响了电荷转移动态.
研究的目的:
- 通过木交叉合合成新型20-替代甲衍生物 (ZCPh).
- 为了研究基于ZCPh的供体-受体二极管中的光诱导电子转移动力学.
- 为了比较电子合和电荷传输速率与类似的基于氨酸的二.
主要方法:
- 苏苏基交叉合反应用于合成ZCPh.
- 合成含有纳烯或二烯 (二氧化) 接受器的供体-接受体二.
- 电子偏磁共振 (EPR) 和电子核双共振 (ENDOR) 光谱学.
- 密度函数理论 (DFT) 的计算.
主要成果:
- ZCPh衍生物是从叶绿素a.合成的,产量很好.
- 谱学和计算分析显示,ZCPh基离子的最高占用分子轨道 (HOMO) 在C20位置具有最小的自旋密度.
- DFT的计算表明,接受器上的负电荷显著地将ZCPh和氨酸基离子中的电荷密度转移到环上.
- 这种电荷再分配导致几乎相同的电子合矩阵元素 (V) 和类似的电子传输速率.
结论:
- 合成的ZCPh衍生物是捐赠者-接受者系统的有效构建块.
- 尽管基离子中的自旋密度分布有差异,但ZCPh和氨酸二中的电子合和电子转移速率是可比的.
- 受体负电荷的接近性决定了电子合,最大限度地减少了内在的供体差异.
相关概念视频
Electron Transport Chains
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
Electrochemical Gradient and Channel Proteins: An Overview
An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
Electron Transport Chain Components
The electron transport chain (ETC) is a crucial metabolic pathway that facilitates energy conversion in prokaryotic and eukaryotic cells. In eukaryotes, the ETC comprises four membrane-associated protein complexes in the inner mitochondrial membrane. In prokaryotes, the ETC in the plasma membrane can vary in composition, with fewer or different complexes depending on the organism and environmental conditions. These complexes transfer electrons from electron donors, such as NADH and FADH2, to...


