Asymmetric reactions induced by electron spin polarization
Asymmetric reactions induced by electron spin polarization
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DOI：
10.1039/d0cp03129a
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发表时间：
2020-10-14
影响因子：
3.3
通讯作者：
Waldeck, D. H.
中科院分区：
文献类型：
--
作者：
Bloom, B. P.;Lu, Y.;Waldeck, D. H.
描述了手性诱导自旋选择性（CISS）效应的基本方面及其对自旋控制化学和不对称电化学反应的影响。通过电解产生氧气作为一个例子，其中手性为基础的自旋过滤和自旋选择规则可以用来提高反应的效率和选择性进行了讨论。接下来的讨论转移到说明如何的自旋选择性的手性分子（CISS属性）允许一个使用的电子自旋作为诱导不对称反应和促进对映体特异性过程的手性偏置。描述了两种使用极化电子自旋作为手性试剂的对映选择性电化学反应：从外消旋混合物中拆分对映体的对映选择性电还原反应和从非手性单体中生成手性聚合物的氧化电聚合反应。还讨论了一种互补的方法，即使用自旋极化，但在其他方面的非手性，分子膜对映体特异性地与一种对映体从外消旋混合物。这些反应类型中的每一种都使用磁化膜来产生自旋极化电子，并且可以通过选择磁化方向（北极对南极）来选择对映体特异性。讨论了这一领域未来研究的可能途径及其与现有基于手性电极的方法的兼容性。
Essential aspects of the chiral induced spin selectivity (CISS) effect and their implications for spin-controlled chemistry and asymmetric electrochemical reactions are described. The generation of oxygen through electrolysis is discussed as an example in which chirality-based spin-filtering and spin selection rules can be used to improve the reaction's efficiency and selectivity. Next the discussion shifts to illustrate how the spin selectivity of chiral molecules (CISS properties) allows one to use the electron spin as a chiral bias for inducing asymmetric reactions and promoting enantiospecific processes. Two enantioselective electrochemical reactions that have used polarized electron spins as a chiral reagent are described; enantioselective electroreduction to resolve an enantiomer from a racemic mixture and an oxidative electropolymerization to generate a chiral polymer from achiral monomers. A complementary approach that has used spin-polarized, but otherwise achiral, molecular films to enantiospecifically associate with one enantiomer from a racemic mixture is also discussed. Each of these reaction types use magnetized films to generate the spin polarized electrons and the enantiospecificity can be selected by choice of the magnetization direction, North pole versus South pole. Possible paths for future research in this area and its compatibility with existing methods based on chiral electrodes are discussed.