†Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
‡Department of Chemical and Geological Science, University of Modena and Reggio Emilia, Via G. Campi 183, 41125 Modena, Italy.
ACS Nano. 2015 Mar 24;9(3):3377-84. doi: 10.1021/acsnano.5b00832. Epub 2015 Mar 12.
This work examines whether electrochemical redox reactions are sensitive to the electron spin orientation by examining the effects of magnetic field and molecular chirality on the charge transfer process. The working electrode is either a ferromagnetic nickel film or a nickel film that is coated with an ultrathin (5-30 nm) gold overlayer. The electrode is coated with a self-assembled monolayer that immobilizes a redox couple containing chiral molecular units, either the redox active dye toluidine blue O with a chiral cysteine linking unit or cytochrome c. By varying the direction of magnetization of the nickel, toward or away from the adsorbed layer, we demonstrate that the electrochemical current depends on the orientation of the electrons' spin. In the case of cytochrome c, the spin selectivity of the reduction is extremely high, namely, the reduction occurs mainly with electrons having their spin-aligned antiparallel to their velocity.
这项工作通过研究磁场和分子手性对电荷转移过程的影响，检验了电化学氧化还原反应是否对电子自旋取向敏感。工作电极是铁磁镍膜或涂有超薄膜（5-30nm）金覆盖层的镍膜。电极涂有自组装单层，固定有包含手性分子单元的氧化还原对，要么是具有手性半胱氨酸连接单元的氧化还原活性染料甲苯胺蓝 O，要么是细胞色素 c。通过改变镍的磁化方向，朝向或远离吸附层，我们证明电化学电流取决于电子自旋的取向。在细胞色素 c 的情况下，还原的自旋选择性极高，即还原主要发生在其自旋与速度平行的电子上。
