Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, U.K.
J Phys Chem Lett. 2021 Feb 11;12(5):1407-1412. doi: 10.1021/acs.jpclett.1c00009. Epub 2021 Jan 29.
Recently, there has been much interest in the chirality-induced spin selectivity effect, whereby electron spin polarization, which is dependent on molecular chirality, is produced in electrode-molecule electron transfer processes. Naturally, one might consider if a similar effect can be observed in simple molecular charge transfer reactions, for example, in light-induced electron transfer from an electron donor to an electron acceptor. In this work, I explore the effect of electron transfer on spins in chiral single radicals and chiral radical pairs using Nakajima-Zwanzig theory. In these cases, chirality, in conjuction with spin-orbit coupling, does not lead to spin polarization, but instead, the electron transfer generates quantum coherence between spins states. In principle, this chirality-induced spin coherence could manifest in a range of experiments, and in particular, I demonstrate that the out of phase electron spin echo envelope modulation pulse electron paramagnetic resonance experiment would be able to detect this effect in oriented radical pairs.
最近，手性诱导自旋选择性效应引起了广泛关注，在电极-分子电子转移过程中，分子手性依赖性的电子自旋极化被产生。自然而然，人们可能会考虑是否可以在简单的分子电荷转移反应中观察到类似的效应，例如，在光诱导的电子从给体转移到受体的过程中。在这项工作中，我使用中岛-津一郎理论研究了电子转移对手性单自由基和手性自由基对中自旋的影响。在这些情况下，手性与自旋轨道耦合相结合不会导致自旋极化，而是电子转移会在自旋态之间产生量子相干。原则上，这种手性诱导的自旋相干性可以在一系列实验中表现出来，特别是，我证明了取向自由基对的出相电子自旋回波包络调制脉冲电子顺磁共振实验能够检测到这种效应。
