Magneto-chiral effects

Chirality and magnetism have a common fate that finds its roots back to the 19th century: the similarity of the optical response of chiral and magnetic media when exposed to circularly polarized light. This raised a lot of hopes about the possibility to control chiral systems with magnetic fields.

Based on symmetry arguments, an interplay between chirality and magnetism appears to be possible only if the magnetic field is associated with another physical influence like electric current or unpolarized light.

Both possibilities are explored at LNCMI, e.g. magneto-chiral anisotropy in electronic conduction at LNCMI-T and magneto-chiral dichroism in the UV-Visible range at LNCMI-G.

As direct effects have been demonstrated, the reverse effects are theoretically possible. In turn, enantioselective photochemistry using unpolarized light under magnetic field has once been undertaken at LNCMI-T and proposed as a mechanism for the homochirality of life. Enantioselective processes using electric current under magnetic field remains to be examplified. Magneto-chiral effects are also explored in order to develop a enantiosensitivite liquid NMR without adding any optically active additives.

Voir aussi dans «Atoms, Molecules, Soft & Photons»

Magnetoscience Molecular Magnetism