Chiral symmetry is ubiquitous in Biology, Physics, and Chemistry. The biomolecules essential for life on Earth—such as deoxyribonucleic acid (DNA), sugars, and proteins—display homochirality that affects their function in biological processes. Ten years ago, it was discovered that electron transfer through chiral molecules depends on the direction of the electron spin, and more recently, it was shown that the charge displacement in chiral molecules creates transient spin polarization. Thus, the properties of ferromagnet/chiral molecule interfaces are affected by spin exchange interactions, via the overlap of the chiral molecule with the ferromagnet's spin wave function. This effect offers a mechanism for homochiral bias in Biology, which was previously unappreciated, and an approach to enantioselective chemistry and chiral separations, which is controlled by the electron spin.

Chirality is a fundamental manifestation of symmetry in nature and is found in almost all aspects of living systems.1 DNA, peptides, proteins, sugars, and many other molecules are chiral. In living systems, chiral biomolecules exist predominantly in only one of their possible enantiomeric forms,2 e.g., amino acids in the L-form and sugars in the D-form. It is known that enantioselectivity in biological processes is highly important. Opposite enantiomers of a chiral drug molecule can have extremely different biological effects. One infamous example is the drug thalidomide that was marketed as a mixture of its two enantiomers; one of them had the desired therapeutic effect, while the other enantiomer caused severe birth defects.3 Enantiospecificity in molecular recognition is commonly believed to manifest through the three-dimensional spatial arrangement of a chiral molecule's surface and intermolecular interactions with other molecules in solution, the “lock and key” model.4 In fact, the conventional wisdom in chemistry is that an enantioselective chemical process requires a chiral bias. Commonly, this bias is expressed as one enantiomer of a chiral reactant, a chiral catalyst, or a chiral solvent.5,6 The Chiral Induced Spin Selectivity (CISS) effect,7vide infra, implies that electron spin control can be used to realize enantioselectivity in chemical reactions and molecular separations.

The CISS effect refers to the correlation found between the electron transmission through chiral molecules and the electron spin.8 Depending on the handedness of the molecule, electrons of a certain spin can traverse the molecule more easily in one direction than in the other.9 These directions are reversed for electrons of opposite spin. Thus, charge displacement and charge transfer in chiral molecules generate a spin-polarized electron distribution. This effect is general and has been measured for a number of different chiral organic molecules, nucleic acids,10,11 helicene,12 and peptides.13 Since its discovery, the effect has been observed experimentally and verified in different systems.14–19 These observations are surprising as spin filtering is commonly associated with magnetic materials or with substances that possess large spin–orbit coupling, rather than organic molecules that typically are neither magnetic nor have large spin–orbit coupling. Often, the theoretical descriptions of CISS20–29 couple the electron spin direction and the velocity to the helical geometry of a molecule, using scattering or tight binding mechanisms. While the spin–orbit coupling alone is too weak to account for the CISS effect, its combination with a dipole electric field30 and/or spin exchange interaction with a substrate can lead to strong spin-dependent transmission at room temperature. The CISS effect provides a dissymmetric physical force that could explain (or help explain) homochirality in biology.31 Experiments show that CISS contributes to long distance dissipationless electron transport,32 local charge separation,33 and biorecognition between chiral molecules34—all processes that are important in biology.

Attempts to identify dissymmetric physical forces that could explain biological homochirality have a long history.35 Most attempts failed, and only vortex mechanical forces, such as stirring of solutions36 or inducing vortex flow,37 maybe the “weak force”38 have proved to be significant enough to provide some differentiation between the forces operating on opposite enantiomers. Using a magnetic field in conjunction with photoinduced processes can initiate an enantioselective process, e.g., magnetochiral anisotropy.39 Recently, it was demonstrated that the CISS effect gives rise to an enantioselective interaction of chiral molecules with a substrate magnetized perpendicular to its surface that is large enough to perform enantioseparation of a racemic mixture.40 As a corollary, charge redistribution in chiral molecules is also accompanied by enantiospecific spin polarization, indicating that chiral molecules will interact by spin exchange with perpendicularly magnetized surfaces. This interaction should be spin sensitive by virtue of short-range spin-exchange interactions. The study was followed by additional studies on enantiospecific crystallization onto magnetized surfaces from racemic solutions.41 

The polarized charge displacement of chiral molecules generates transient spin polarization; for a chiral molecule interacting with a magnetized substrate, or another chiral molecule, spin exchange interactions are critical at short range. For example, when two helical chiral molecules of the same handedness interact, the charge polarization is accompanied by a spin polarization acting in the same direction, e.g., pointing outward along the helical axis. In this case, the exchange interaction between the molecules is characterized by two opposite spin polarization directions, analogous to a singlet state. In contrast, the spin polarizations of two interacting molecules of opposite chirality have opposite directions. Here, the exchange interaction between the molecules corresponds to two parallel spins, analogous to a triplet state.33 Consequently, spin polarization makes the overall interaction between chiral molecules enantiospecific. Most force fields that are used in (bio)molecular simulations do not include these effects.

The spin exchange interactions are critical for understanding the interaction of chiral molecules with magnetic substrates. When chiral molecules are adsorbed on a soft ferromagnet, which is commonly magnetized by either external magnetic fields or spin polarized currents, the magnetization can be switched.42 Magnetization switching depends on the handedness of the adsorbed molecules. In the transient state, less than 1013 electrons per cm2 are transferred between the substrate and the molecules. These are sufficient to induce magnetization reversal in thin ferromagnetic films. These results led us to consider the possible enantiospecific interaction between chiral molecules and perpendicularly magnetized surfaces and to use it to facilitate the separation of a racemic mixture into its two enantiomeric components simply by allowing the mixture to interact with a magnetized substrate.

Figure 1 summarizes experimental results for the enantiospecific interaction of L– and D–polyalanine (PAL)-based peptides with a thin magnetic film. A thiolated α-helix polyalanine SH-CAAAAKAAAAKAAAAKAAAAKAAAAKAAAAKAAAAK (C, A, and K represent cysteine, alanine, and lysine, respectively) was exposed to a ferromagnetic (FM) cobalt film covered with 5 nm of gold for 2 s. SiO2 nanoparticles (NPs) were attached to the adsorbed PAL to act as a marker in the scanning electron microscopy (SEM) micrographs for the monolayer adsorption density. Figures 1(a) and 1(b) show SEM images of the L-enantiomer adsorbed on the FM substrate, with the latter magnetized up (panel a) or down (panel b). The concentration of adsorbed NPs in (panel a) is 40 (± 4) × 109 NPs/cm2, whereas the concentration in panel b is 6 (± 1) × 109 NPs/cm2. The results of the complementary experiment with D-PAL are shown in Figs. 1(c) and 1(d), with concentrations of 10 (± 2) × 109 and 40 (± 5) × 109 NPs/cm2 found for the up- and down-magnetized substrates. As a control experiment, L- and D-enantiomers were also adsorbed on a nonmagnetic, pure gold substrate, with an external magnetic field applied either normal or antinormal to the substrate. In this case, no enantioselectivity was observed. Figure 1(e) shows a comparison for all the measurements in a bar graph form. The L enantiomer with the natural chirality is purer than the D enantiomer, and as a result, the enantiomer selectivity is improved.

FIG. 1.

Enantioselective adsorption of a peptide. Adsorption of the PAL oligopeptide [inset of (e)] on FM samples (silicon with a 1.8-nm Co film and a 5-nm Au film) magnetized with the magnetic dipole pointing up (H+) or down (H–) relative to the substrate surface. SiO2 nanoparticles were attached to the adsorbed oligopeptides. Panels (a) and (b) L-PAL [and (c) and (d) D-PAL] were adsorbed for 2 s on a substrate magnetized up or down. Panel (e) summarizes the nanoparticle adsorption densities shown in (a) to (d), compared to the adsorption density on Au with an applied external magnetic field (red bars).

FIG. 1.

Enantioselective adsorption of a peptide. Adsorption of the PAL oligopeptide [inset of (e)] on FM samples (silicon with a 1.8-nm Co film and a 5-nm Au film) magnetized with the magnetic dipole pointing up (H+) or down (H–) relative to the substrate surface. SiO2 nanoparticles were attached to the adsorbed oligopeptides. Panels (a) and (b) L-PAL [and (c) and (d) D-PAL] were adsorbed for 2 s on a substrate magnetized up or down. Panel (e) summarizes the nanoparticle adsorption densities shown in (a) to (d), compared to the adsorption density on Au with an applied external magnetic field (red bars).

Close modal

Based on the interaction of chiral molecules with a magnetic substrate, magnetized perpendicular its surface, enantiopure crystallization (and separation) that is controlled by the magnetization direction was demonstrated.41 This approach can be used to separate enantiomers spatially by using spin exchange interactions and magnetized surfaces. Enantioselective crystallization is induced from a racemic solution. The enantioselectivity is manipulated by the magnetization direction of the magnetized surface. Asymmetric induction was demonstrated for three amino acids: Asparagine (Asn), glutamic acid hydrochloride (Glu•HCl), and threonine (Thr). The L enantiomer was crystallized preferentially at one pole of the magnet, and the D enantiomer was found to crystallize preferentially at the other pole. Figure 2(a) shows the results for the enantiospecific crystallization of Glu•HCl. The red line is a guide to the eye, schematically separating between the North and South magnetic part of the magnetic substrate. Figure 2(b) presents the amount of crystals formed in each half of the magnetic substrate. The enantiopurity of the crystallization reached a value of 80%.

FIG. 2.

Enantioselective crystallization of glutamic acid hydrochloride on a 2-in. wafer with a magnet below. A racemic solution of Glu•HCl crystallized on the Ni/Au surface (120 nm/10 nm). (a) In red are D-Glu•HCl crystals; in blue are L-Glu•HCl crystals. (b) The amount of L-Glu•HCl (blue) and D-Glu•HCl (red) crystals in each half of the magnetized surface is shown as a bar graph.

FIG. 2.

Enantioselective crystallization of glutamic acid hydrochloride on a 2-in. wafer with a magnet below. A racemic solution of Glu•HCl crystallized on the Ni/Au surface (120 nm/10 nm). (a) In red are D-Glu•HCl crystals; in blue are L-Glu•HCl crystals. (b) The amount of L-Glu•HCl (blue) and D-Glu•HCl (red) crystals in each half of the magnetized surface is shown as a bar graph.

Close modal

The ability to create a current of spin polarized electrons without a ferromagnetic material, or magnetize a ferromagnetic material locally, offers a strategy for overcoming some of the difficulties one faces when attempting to utilize spin in information technologies. For device applications, inorganic films are valued for supplying the robustness that is needed for integrated circuit technology. Indeed, some evidence for the CISS effect in chiral inorganic films was shown recently.43 One advantage of CISS is the ability to use even a single chiral molecule as a spin injector, thereby being able to reduce the size of a spin injector much below the size dictated by the ferromagnetic-superparamagnetic transition, which is typically a few tens of nanometers. Preliminary results show that ferromagnetism can be imprinted on superparamagnetic 10 nm nanoparticles by asymmetric adsorption of polyalanine chiral molecules.44 Another advantage of the CISS effect is the high spin polarization achieved, unlike what one faces with a high Schottky barrier, which tends to reduce the spin polarization. Moreover, the sensitivity of the charge distribution in adsorbed chiral molecules to the change in a ferromagnetic substrate's magnetization, the spinterface property, may prove to be useful for sensing and for various spintronics applications.

As indicated above, surfaces will play a major role in developing CISS-based spinterface devices. Controlling and engineering the spinterface will require understanding how to relate the transient spin polarization in the chiral molecules/material, which arises from spin–orbit coupling, to the spin exchange interaction between the spin-polarized chiral layer and the substrate. The spin exchange energy is much larger than the spin–orbit coupling in chiral molecules, and it will be important to perform systematic studies that examine how the spin-exchange interactions between a chiral layer and substrate change with the type of magnetic material, its coercivity, and its magnetization direction. Such studies should help to develop design principles for optimizing the spin selectivity and performance of spinterface devices.

In terms of chemistry, the CISS effect provides a way to introduce spin-polarized electrons into a “chemical reactor.” Some recent experiments are pointing the way to applications of the CISS effect for enhancing selectivity in reactions. It has been shown that when electrochemical water splitting occurs with an anode that accepts preferentially one spin, the process is enhanced and the formation of the by-product, hydrogen peroxide, is diminished. The spin specificity of the electrode is achieved either by coating the electrode with a chiral overlayer of molecules45,46 or oxide41,43 or by using a magnetized electrode.47 These studies indicate that reaction selectivity can be affected by spin-polarized electrons, and CISS implies that spin-polarized electrons will interact in an enantiospecific manner with chiral molecules. Thus, it may be possible to replace a conventional enantiopure chemical reagent by spin-polarized electrons that provide the chiral bias for enantioselective reactions. One can even envision that spin-polarized electrons from magnetic electrodes will be able to induce enantiospecific electrochemical redox reactions.

The charge distribution in chiral molecules adsorbed on a ferromagnet responds to the change in the direction of the spin in the substrate. This effect can be applied as a simple and robust method for locally resolved magnetic imaging—based on the short-range spin exchange interactions that can be achieved using a conventional AFM tip functionalized with a chiral molecule.48 

Although the applications of the CISS effect are many, it is important to realize that a more basic understanding of the phenomenon is required. While current theories can account for the qualitative aspects of CISS, theories that predict the magnitude of the spin polarization effect (experiments give effects that are ten, or more, times larger than theoretical models) from the molecular structure are not yet available. Schemes for enhancing spin polarization49 require a better understanding and may enable one to increase the effect by combining the chiral molecules with other elements, for example, metal ions, or large dipole moments. To support the theoretical effort, systematic studies that compare between different substrates and different types of chiral molecules (and chiral materials) should be done. The experiments done so far indicate that CISS is a robust effect, with the polarization value varying somewhat depending on the specific molecule. Therefore, one major theoretical challenge is to explain this robustness from general principles, without resorting to detailed features of the molecular structure.

The CISS effect is a recent comer to spin-chemistry and spin-physics with a bright future.

1.
L.
Pasteur
, La dissymétrie moléculaire, Rev. Scient. 3, vii: 2–6, in Oeuvres de Louis Pasteur I (
1884
), p.
369
.
2.
S. F.
Mason
, “
Origins of bio molecular handedness
,”
Nature
311
,
19
23
(
1984
).
3.
S. W.
Smith
, “
Chiral toxicology: It's the same thing…only different
,”
Toxicol. Sci.
110
,
4
30
(
2009
).
4.
D. E.
Koshland
, “
The Key–Lock theory and the Induced Fit theory
,”
Angew. Chem.
33
,
2375
2378
(
1995
).
5.
L. A.
Nguyen
,
H.
He
, and
C.
Pham-Huy
, “
Chiral drugs: An overview
,”
Int. J. Biomed. Sci.
2
,
85
(
2006
).
6.
L. D.
Barron
, “
Can a magnetic field induce absolute asymmetric synthesis?
,”
Science
266
,
1491
1492
(
1994
).
7.
R.
Naaman
,
Y.
Paltiel
, and
D. H.
Waldeck
, “
Chiral molecules and the electron spin
,”
Nat. Rev. Chem.
3
,
250
260
(
2019
).
8.
R.
Naaman
and
D. H.
Waldeck
, “
Spintronics and chirality: Spin selectivity in electron transport through chiral molecules
,”
Ann. Rev. Phys. Chem.
66
,
263
281
(
2015
).
9.
B.
Göhler
,
V.
Hamelbeck
,
T. Z.
Markus
,
M.
Kettner
,
G. F.
Hanne
,
Z.
Vager
,
R.
Naaman
, and
H.
Zacharias
, “
Spin selectivity in electron transmission through self-assembled monolayers of double-stranded DNA
,”
Science
331
,
894
(
2011
).
10.
Z.
Xie
,
T. Z.
Markus
,
S. R.
Cohen
,
Z.
Vager
,
R.
Gutierrez
, and
R.
Naaman
, “
Spin specific electron conduction through DNA oligomers
,”
Nano Lett.
11
,
4652
4655
(
2011
).
11.
R. A.
Rosenberg
,
D.
Mishra
, and
R.
Naaman
, “
Chiral selective chemistry induced by natural selection of spin-polarized electrons
,”
Angew. Chem.
54
,
7295
7298
(
2015
).
12.
V.
Kiran
,
S. P.
Mathew
,
S. R.
Cohen
,
I. H.
Delgado
,
J.
Lacour
, and
R.
Naaman
, “
Helicenes—A new class of organic spin filter
,”
Adv. Mat.
28
,
1957
1962
(
2016
).
13.
M.
Kettner
,
B.
Göhler
,
H.
Zacharias
,
D.
Mishra
,
V.
Kiran
,
R.
Naaman
,
C.
Fontanesi
,
D. H.
Waldeck
,
S.
Sęk
,
J.
Pawłowski
, and
J.
Juhaniewicz
, “
Spin filtering in electron transport through chiral oligopeptides
,”
J. Phys. Chem. C
119
,
14542
14547
(
2015
).
14.
S.
Ravi
,
P.
Sowmiya
, and
A.
Karthikeyan
, “
Magnetoresistance and spin-filtering efficiency of DNA-sandwiched ferromagnetic nanostructures
,”
Spin
3
,
1350003
(
2013
).
15.
K. M.
Alam
and
S.
Pramanik
, “
Spin filtering through single-wall carbon nanotubes functionalized with single-stranded DNA
,”
Adv. Func. Mater.
25
,
3210
(
2015
).
16.
M. Á.
Niño
,
I. A.
Kowalik
,
F. J.
Luque
,
D.
Arvanitis
,
R.
Miranda
, and
J. J.
Miguel
, “
Enantiospecific spin polarization of electrons photoemitted through layers of homochiral organic molecules
,”
Adv. Mater.
26
,
7474
7479
(
2014
).
17.
O.
Ben Dor
,
N.
Morali
,
S.
Yochelis
,
L. T.
Baczewski
, and
Y.
Paltiel
, “
Local light-induced magnetization using nanodots and chiral molecules
,”
Nano Lett.
14
,
6042
6049
(
2014
).
18.
M.
Kettner
,
V. V.
Maslyuk
,
D.
Nurenberg
,
J.
Seibel
,
R.
Gutierrez
,
G.
Cuniberti
,
K. H.
Ernst
, and
H.
Zacharias
, “
Chirality-dependent electron spin filtering by molecular monolayers of helicenes
,”
J. Phys. Chem. Lett.
9
,
2025
2030
(
2018
).
19.
L.
Turin
,
E. M. C.
Skoulakis
, and
A. P.
Horsfield
, “
Electron spin changes during general anesthesia in Drosophila
,”
Proc. Natl. Acad. Sci. U. S. A.
111
,
E3524
E3533
(
2014
).
20.
T.
Koretsune
,
R.
Arita
, and
H.
Aoki
, “
Magneto-orbital effect without spin-orbit interactions in a noncentrosymmetric zeolite-templated carbon structure
,”
Phys. Rev. B
86
,
125207
(
2012
).
21.
S.
Yeganeh
,
M. A.
Ratner
,
E.
Medina
, and
V.
Mujica
, “
Chiral electron transport: Scattering through helical potentials
,”
J. Chem. Phys.
131
,
014707
(
2009
).
22.
E.
Medina
,
F.
Lopez
,
M. A.
Ratner
, and
V.
Mujica
, “
Chiral molecular films as electron polarizers and polarization modulator
,”
Europhys. Lett.
99
,
17006
(
2012
).
23.
R.
Gutierrez
,
E.
Díaz
,
R.
Naaman
, and
G.
Cuniberti
, “
Spin-selective transport through helical molecular systems
,”
Phys. Rev. B
85
,
081404
(
2012
);
R.
Gutierrez
,
E.
Díaz
,
C.
Gaul
,
T.
Brumme
,
F.
Domínguez-Adame
, and
G.
Cuniberti
, “
Modeling spin transport in helical fields: Derivation of an effective low-dimensional Hamiltonian
,”
J. Phys. Chem. C
117
,
22276
22284
(
2013
).
24.
A. M.
Guo
and
Q. F.
Sun
, “
Spin-selective transport of electrons in DNA double helix
,”
Phys. Rev. Lett.
108
,
218102
(
2012
);
[PubMed]
A. M.
Guo
and
Q. F.
Sun
, “
Sequence-dependent spin-selective tunneling along double-stranded DNA
,”
Phys. Rev. B
86
,
115441
(
2012
);
A. M.
Guo
and
Q. F.
Sun
, “
Spin-dependent electron transport in protein-like single-helical molecules
,”
Proc. Natl. Acad. U. S. A.
111
,
11658
11662
(
2014
).
25.
A. A.
Eremko
and
V. M.
Loktev
, “
Spin sensitive electron transmission through helical potentials
,”
Phys. Rev. B
88
,
165409
(
2013
).
26.
D.
Rai
and
M.
Galperin
, “
Electrically driven spin currents in DNA
,”
J. Phys. Chem. C
117
,
13730
13737
(
2013
).
27.
J.
Gersten
,
K.
Kaasbjerg
, and
A.
Nitzan
, “
Induced spin filtering in electron transmission through chiral molecular layers adsorbed on metals with strong spin-orbit coupling
,”
J. Chem. Phys.
139
,
114111
(
2013
).
28.
S. L.
Kuzmin
and
W. W.
Duley
, “
Dependence of exchange bias on core/shell relative dimension in ferromagnetic/antiferromagnetic nanoparticles
,”
Phys. Lett. A
378
,
1667
1674
(
2014
).
29.
S.
Matityahu
,
Y.
Utsumi
,
A.
Aharony
,
O.
Entin-Wohlman
, and
C. A.
Balseiro
, “
Spin-dependent transport through a chiral molecule in the presence of spin-orbit interaction and non-unitary effects
,”
Phys. Rev. B
93
,
075407
(
2016
).
30.
K.
Michaeli
,
V.
Varade
,
R.
Naaman
, and
D. H.
Waldeck
, “
A new approach towards spintronics-spintronics with no magnets
,”
J. Phys.: Condens. Matter
29
,
103002
(
2017
).
31.
K.
Michaeli
,
N.
Kantor-Uriel
,
R.
Naaman
, and
D. H.
Waldeck
, “
The electron's spin and molecular chirality—How are they related and how do they affect life processes?
,”
Chem. Soc. Rev.
45
,
6478
6487
(
2016
).
32.
E.
Smolinsky
,
A.
Neubauer
,
A.
Kumar
,
S.
Yochelis
,
E.
Capua
,
R.
Carmieli
,
Y.
Paltiel
,
R.
Naaman
, and
K.
Michaeli
, “
Electric field controlled magnetization in GaAs/AlGaAs heterostructures-chiral organic molecules hybrids
,”
J. Phys. Chem. Lett.
10
,
1139
1145
(
2019
).
33.
N.
Peer
,
I.
Dujovne
,
S.
Yochelis
, and
Y.
Paltiel
, “
Nanoscale charge separation using chiral molecules
,”
ACS Photonics
2
,
1476
(
2015
).
34.
A.
Kumar
,
E.
Capua
,
M. K.
Kesharwani
,
J. M. L.
Martin
,
E.
Sitbon
,
D. H.
Waldeck
, and
R.
Naaman
, “
Chirality-induced spin polarization places symmetry constraints on biomolecular interactions
,”
Proc. Natl Acad. Sci. U. S. A.
114
,
2474
2478
(
2017
).
35.
T.
Ruchon
,
M.
Vallet
,
J.-Y.
Thépot
,
A.
Le Floch
, and
R. W.
Boyd
, “
Experimental evidence of magnetochiral interaction in Pasteur's tartrates
,”
C. R. Phys.
5
,
273
277
(
2004
).
36.
K.
Okano
,
O.
Arteaga
,
J. M.
Ribo
, and
T.
Yamashita
, “
Emergence of chiral environments by effect of flows: The case of an ionic oligomer and congo red dye
,”
Chemistry
17
,
9288
9292
(
2011
).
37.
K.
Okano
and
T.
Yamashita
, “
Formation of chiral environments by a mechanical induced vortex flow
,”
ChemPhysChem
13
,
2263
2271
(
2012
).
38.
J. M.
Dreiling
and
T. J.
Gay
, “
Chirally sensitive electron-induced molecular breakup and the Vester-Ulbricht hypothesis
,”
Phys. Rev. Lett.
113
,
118103
(
2014
).
39.
G. L. J. A.
Rikken
and
E.
Raupach
, “
Observation of magneto-chiral dichroism
,”
Nature
390
,
493
494
(
1997
).
40.
K. B.
Ghosh
,
O.
Ben Dor
,
F.
Tassinari
,
E.
Capua
,
S.
Yochelis
,
A.
Capua
,
S.-H.
Yang
,
S. S. P.
Parkin
,
S.
Sarkar
,
L.
Kronik
,
L. T.
Baczewski
,
R.
Naaman
, and
Y.
Paltiel
, “
Enantio-specific interaction of chiral molecules with magnetic substrates
,”
Science
360
,
1331
(
2018
).
41.
F.
Tassinari
,
J.
Steidel
,
S.
Paltiel
,
C.
Fontanesi
,
M.
Lahav
,
Y.
Paltiel
, and
R.
Naaman
, “
Enantioseparation by crystallization using magnetic substrates
,”
Chem. Sci.
10
,
5246
5250
(
2019
).
42.
O.
Ben Dor
,
S.
Yochelis
,
A.
Radko
,
K.
Vankayala
,
E.
Capua
,
A.
Capua
,
S.-H.
Yang
,
L. T.
Baczewski
,
S. S. P.
Parkin
,
R.
Naaman
, and
Y.
Paltiel
, “
Magnetization switching in ferromagnets by adsorbed chiral molecules without current or external magnetic field
,”
Nat. Commun.
8
,
14567
(
2017
).
43.
K. B.
Ghosh
,
W.
Zhang
,
F.
Tassinari
,
Y.
Mastai
,
O.
Lidor-Shalev
,
R.
Naaman
,
P.
Möllers
,
D.
Nürenberg
,
H.
Zacharias
,
J.
Wei
,
E.
Wierzbinski
, and
D. H.
Waldeck
, “
Controlling chemical selectivity in electrocatalysis with chiral CuO coated electrodes
,”
J. Phys. Chem. C
123
,
3024
3031
(
2019
).
44.
G.
Koplovitz
,
G.
Leitus
,
S.
Ghosh
,
B. P.
Bloom
,
S.
Yochelis
,
D.
Rotem
,
F.
Vischio
,
M.
Striccoli
,
E.
Fanizza
,
R.
Naaman
,
D. H.
Waldeck
,
D.
Porath
, and
Y.
Paltiel
, “
Single domain 10 nm ferromagnetism imprinted on superparamagnetic nanoparticles using chiral molecules
,”
Small
15
,
1804557
(
2019
).
45.
W.
Mtangi
,
V.
Kiran
,
C.
Fontanesi
, and
R.
Naaman
, “
The role of the electron spin polarization in water splitting
,”
J. Phys. Chem. Lett.
6
,
4916
4922
(
2015
).
46.
W.
Mtangi
,
F.
Tassinari
,
K.
Vankayala
,
A. V.
Jentzsch
,
B.
Adelizzi
,
A. R. A.
Palmans
,
C.
Fontanesi
,
E. W.
Meijer
, and
R.
Naaman
, “
Control of electrons' spin eliminates hydrogen peroxide formation during water splitting
,”
J. Am. Chem. Soc.
139
,
2794
2798
(
2017
).
47.
F. A.
Garcés-Pineda
,
M.
Blasco-Ahicart
,
D.
Nieto-Castro
,
N.
López
, and
J. R.
Galán-Mascarós
, “
Direct magnetic enhancement of electrocatalytic water oxidation in alkaline media
,”
Nat. Energy
4
,
519
525
(
2019
).
48.
A.
Ziv
,
A.
Saha
,
H.
Alpern
,
N.
Sukenik
,
L. T.
Baczewski
,
S.
Yochelis
,
M.
Reches
, and
Y.
Paltiel1
, “
AFM-based spin exchange microscopy using chiral molecules
,”
Adv. Mater.
1904206
(
2019
).
49.
K.
Michaeli
and
R.
Naaman
, “
Origin of spin-dependent tunneling through chiral molecules
,”
J. Phys. Chem. C
123
,
17043
17048
(
2019
).