在光系II中氨酸氧化模型中的质子合电子转移
Claudio Carra1, Nedialka Iordanova, Sharon Hammes-Schiffer
1Department of Chemistry, 152 Davey Laboratory, Pennsylvania State University, University Park, Pennsylvania, 16802, USA.
Journal of the American Chemical Society
|August 21, 2003
概括
理论计算表明,光系II中的氨酸氧化通过低pH时的质子合电子转移 (PCET) 和高pH时的单电子转移 (ET) 发生. 在ET机制是显著更快.
科学领域:
- 生物物理化学 生物物理化学
- 摄影化学的使用.
- 光合作用研究研究 光合作用研究
背景情况:
- 铁酸氧化对于光系II中的电荷分离至关重要.
- 实验研究表明,氨酸氧化率的pH值和温度依赖.
研究的目的:
- 在光系II中理论模型氨酸氧化.
- 阐明质子合电子转移 (PCET) 和单电子转移 (ET) 的机制.
主要方法:
- 铁氧化模型系统的理论计算.
- 对反应速率的pH和温度依赖性的分析.
主要成果:
- 该模型复制了PCET和ET机制的实验趋势.
- 在pH<10时,PCET占主导地位,而在pH>10时,ET占主导地位.
- 由于溶剂重组和振动重叠等因素,ET比PCET快两倍.
结论:
- 这项研究阐明了氨酸氧化过程中PCET和ET之间的机械转换.
- 理论发现与对反应速率和依赖性的实验观察一致.
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