Theory of the magnetic field modulated geminate recombination of radical ion pairs in polar solvents: Application to the pyrene–N,N‐dimethylaniline system
Theory of the magnetic field modulated geminate recombination of radical ion pairs in polar solvents: Application to the pyrene–N,N‐dimethylaniline system
复制标题
极性溶剂中自由基离子对的磁场调制双子重组理论：在芘-N,N-二甲基苯胺体系中的应用
DOI：
10.1063/1.434868
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发表时间：
1977
影响因子：
4.4
通讯作者：
K. Schulten
中科院分区：
文献类型：
--
作者：
H. Werner;Z. Schulten;K. Schulten
在极性溶剂中由光诱导电子转移产生的自由基离子对，要么在几纳秒内重新组合，要么分离。双相复合过程是由未配对电子自旋的超精细耦合诱导的相干运动控制的，该运动可以被弱外部磁场调制。该过程也产生了众所周知的CIDNP和CIDEP效应，该过程在理论上由随机Liouville方程描述，该方程包含了实际系统的一大组耦合扩散方程。对于这些方程的积分，提出了一种具有空间和时间离散化的有限差分算法。通过与模型系统的Liouville方程的精确解的比较，证明了一个近似Liouville方程只需要单线态和三重态自由基对的两个耦合扩散方程，就足以准确地预测复合产率。然后用近似的刘维尔方程来研究……
Pairs of radical ions generated in polar solvents by photoinduced electron transfer either recombine within a few nanoseconds or separate. The (geminate) recombination process is governed by a hyperfine‐coupling‐induced coherent motion of the unpaired electron spins which can be modulated by weak external magnetic fields. The process which also generates the well‐known CIDNP and CIDEP effects is described theoretically by a stochastic Liouville equation comprising for realistic systems a large set of coupled diffusion equations. For the integration of these equations a finite‐difference algorithm with space and time discretization is developed. By comparison with exact solutions of the Liouville equation for model systems, it is demonstrated that an approximate Liouville equation which entails only two coupled diffusion equations for singlet and triplet radical pairs, respectively, suffices to predict the geminate recombination yields accurately. The approximate Liouville equation is employed then to stud...