Editorial pubs.acs.org/JPCL
Spin for Physical Chemists
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Notes
pin is an intriguing property of subatomic particles, wellknown from undergraduate physical chemistry as the spin “up” or “down” quantum number of the electron. That concept is important for deciding chemical bonds through the various simple to rather complicated spin pairings of electrons in orbitals.1 Spin was identified by Pauli in 1927. A year later, it was defined in Dirac’s development of relativistic quantum mechanics. Spin is an important concept in many areas of chemistry, including molecular spectroscopy, magnetic resonance spectroscopy, molecular magnets, radicals and chemical reactions, and organic spintronics. Perhaps it has acquired more mainstream importance in physics, where it is widely investigated in solid-state physics, quantum information, quantum mechanics, and spintronics. The two Perspective articles featured in this issue of The Journal of Physical Chemistry Letters describe examples of cutting-edge research that bridges chemistry and physics. The Perspective by Naamen and Waldeck discusses a fascinating new area where roles that chirality can contribute to spintronics are examined (Naaman, R.; Waldeck, D. H. The Chiral Induced Spin Selectivity Effect, J. Phys. Chem. Lett. 2012, 16, 2178−2187). For example, they explain how films of chiral molecules can selectively transmit electrons with a certain spin. Demonstrations of this phenomenon are reviewed and include a “spin filter” for photoelectrons ejected from a gold surface through an ordered monolayer comprised of chiral molecules. Another example involves single-molecule conductance measured for spin-polarized electrons tunneling through DNA. It is shown that the tunneling barrier depends on the spin of the tunneling electron, which is a remarkable result. The article by Rao and co-workers provides an informative and comprehensive account of multiferroic materials (Rao, C. N. R.; Sundaresan, A.; Saha, R.. Multiferroic and Magnetoelectric Oxides: The Energing Scenario, J. Phys. Chem. Lett. 2012, 16, 2237−2246). A number of phenomena arising from the interplay of magnetic and ferroelectric properties are reviewed. Ferroelectric materials display tunable polarization, enabling, for example, capacitors to be tuned by an applied potential. Magnetoelectric materials are analogous but display magnetic-field-tunable magnetic or electric polarization. Rao et al. explain how novel solid-state structures can exhibit both of these properties owing to their unusual structures and chemical bonding. Doubtless, there are many opportunities for future physical chemistry research investigating the properties and applications of electron spin, from molecules to nanoscale systems. We hope that these Perspectives serve as inspiration.
Views expressed in this Editorial are those of the author and not necessarily the views of the ACS.
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REFERENCES
(1) Coulson, C. A. Valence; Oxford Clarendon Press: Oxford, U.K., 1952.
Gregory D. Scholes*
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Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. © 2012 American Chemical Society
Published: August 16, 2012 2247
dx.doi.org/10.1021/jz301022x | J. Phys. Chem. Lett. 2012, 3, 2247−2247
