Magnetic effects at the origin of life? It's the spin that makes the difference

Amazing stuff!

"The so-called homochirality of life – the fact that all biomolecules in living organisms only ever occur in one of two mirror-image forms – has puzzled a number of scientific luminaries, from the discoverer of molecular chirality, Louis Pasteur, to William Thomson (Lord Kelvin) and Nobel Prize winner Pierre Curie. A conclusive explanation is still lacking, as both forms have, for instance, the same chemical stability and do not differ from each other in their physico-chemical properties. The hypothesis, however, that the interplay between electric and magnetic fields could explain the preference for one or the other mirror-image form of a molecule – so-called enantiomers – emerged early on. ..."

From the abstract:

"From the beginning of molecular theory, the interplay of chirality and magnetism has intrigued scientists. There is still the question if enantiospecific adsorption of chiral molecules occurs on magnetic surfaces. Enantiomer discrimination was conjectured to arise from chirality-induced spin separation within the molecules and exchange interaction with the substrate's magnetization. Here, it is shown that single helical aromatic hydrocarbons undergo enantioselective adsorption on ferromagnetic cobalt surfaces. Spin and chirality sensitive scanning tunneling microscopy reveals that molecules of opposite handedness prefer adsorption onto cobalt islands with opposite out-of-plane magnetization. As mobility ceases in the final chemisorbed state, it is concluded that enantioselection must occur in a physisorbed transient precursor state. State-of-the-art spin-resolved ab initio simulations support this scenario by refuting enantio-dependent chemisorption energies. These findings demonstrate that van der Waals interaction should also include spin-fluctuations which are crucial for molecular magnetochiral processes."

Magnetic effects at the origin of life? It's the spin that makes the difference

Magnetic effects at the origin of life? It's the spin that makes the difference (EMPA) Biomolecules such as amino acids and sugars occur in two mirror-image forms – in all living organisms, however, only one is ever found. Why this is the case is still unclear. Researchers at Empa and Forschungszentrum Jülich in Germany have now found evidence that the interplay between electric and magnetic fields could be at the origin of this phenomenon.

Enantioselective Adsorption on Magnetic Surfaces (open access)

Fig. 1 Principles of spin-polarized and enantio-resolved STM