Spontaneous resolution chiral surfaces

An interesting possibility raised by this experiment is that of spontaneous resolution in chiral monolayers. If this were a reasonably common phenomenon, it would give yet another possible answer to the perennial question of the chiral environment for the primordial stereospecific condensation reaction that produced the first chiral biopolymers. As our knowledge of chiral monolayers develops, we should have a better perspective on the likelihood of a racemic film spontaneously unmixing to produce patches of enantiomeric film at lower surface energy. The relevance of such a result to the origin of terrestrial life problem will have to remain eternally speculative and untestable. 

Chiral recognition at surfaces occurs at different levels and in different ways. Chiral expression becomes especially obvious in the formation of chiral motifs. That is, chirality is transferred from the single molecule into a supramolecular enantiomorphous structure. Moreover, enantioselective interactions between identical or different species are decisive for spontaneous resolution or play an important role in cooperative phenomena. 

De Feyter S, De Schryver FC (2003) Two-dimensional supramolecular self-assembly probed by scanning tunneling microscopy. Chem Soc Rev 32 393 Ernst K-H (2006) Supramolecular surface chirahty. Top Curr Chem 265 209 Perez-Garcia L, Amabrlino DB (2007) Spontaneous resolution, whence and wither from enantiomorphic solids to chiral liquid crystals, monolayers and macro- and supramolecular polymers and assemblies. Chem Soc Rev 36 941... 

Spontaneous Resolution of Chiral Molecules at a Metal Surface in 2D Space... 

Supramolecular (chbal) self-assembly highlights the importance of the subtle interplay between intermolecular interactions on one hand and molecule-subsbate interactions on the other hand, and thus uncovered some of the basic mechanisms of (chbal) molecular recognition. Key points of interest remain the investigation of how spontaneous resolution can be achieved, conbolled, or tern-plated. Amplification of chirality effects observed at the liquid-solid interface is also waiting to be explored. In general, important new insights are to be expected on the overall role of solvent in dbecting solvent-assisted supramolecular self-assembly processes on surfaces. 

In 2005, Kajitani et al. reported a striking observation rod shaped mesogens show spontaneous deracemization using the same ester molecules shown in Fig. 6 [48]. Soon after this report, however, Walba et al. claimed that the observation must be a surface effect [49]. We repeated the same experiments as they did and concluded that spontaneous deracemization does not occur in this particular compound, but may occur in other compounds. However, since ester molecules seem to have some particular feature in chirality as described in Sect. 2.4, we continued to search for compounds showing chiral resolution and found two homologous series of achiral ester molecules that do [50]. 

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