在光化学诱导的动态核偏振光谱学中,对具有强烈异构的超细合的核的旋转放松效应
Ilya Kuprov1, Timothy D Craggs, Sophie E Jackson
1Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK. ilya.kuprov@chem.ox.ac.uk
Journal of the American Chemical Society
|July 3, 2007
概括
这项研究模拟了19F标记激素对中的核和电子旋转放松. 横向的超细合-g-tensor异构性交叉相关性占主导地位,导致化学诱导的动态核极化 (CIDNP) 中的相反,用于探测蛋白质的移动性.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 频谱学是一种光谱学.
背景情况:
- 核和电子自旋放松在激进对进化中至关重要.
- 了解这些过程是解释磁力运动系统中的实验数据的关键.
- 以前的模型可能无法完全捕捉复杂的放松动态.
研究的目的:
- 开发和验证一个理论模型,用于 19F-标记的双基对的旋转放松.
- 在高磁场中,在纳秒时间尺度上识别主导放松机制.
- 解释化学诱导动态核极化 (CIDNP) 中观察到的相反及其应用.
主要方法:
- 利用实验结果和旋转放松过程的理论建模.
- 采用完整的旋转状态空间和放松超操作器,以实现精确的旋转动力学.
- 在超过10特斯拉的磁场中调查系统.
主要成果:
- 电子核双极交叉放松和纵向高精度合异性质-g-电阻异性质交叉相关性在高电场下是可以忽略不计的.
- 横向的高精度合-g-tensor异质性交叉相关性是主导的放松过程.
- 这一过程导致19F CIDNP信号的相位逆转,以获得较大的旋转相关时间.
结论:
- 开发的旋转动力学模型为磁动力学系统提供了可靠的治疗,具有显著的放松效应.
- 观察到的CIDNP相位逆转是横向DeltaHFC-Deltag交叉相关性的直接结果.
- 这种现象是局部移动性的宝贵探测器,特别是在复杂的生物系统中,如部分变性蛋白质.
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