Chiral self-recognition hydrogen bond interactions

Fig. 5 Typical cyclophane receptors for metal ion complexation (siderophore 31. torand 32, crown ether 36), onium ion-rt interactions (33, crpptophane 38). hydrogen bonding interactions (34-37), and chiral recognition (36-38). Self-assembled cyclophanes 39 and 40.

As observed for the molecular clips reported above, the chiral scaffold is pivotal in promoting homo- or heterochiral self-discrimination. Amide hydrogen bonds were implemented on helicene chiral scaffolds as well, but in this case dimerization of the monomers was characterized by homochiral enantioselective self-recognition, that is self-association between molecules with the same helicity (Fig. 17B) [44], These species dimerized in solution with association constants of 207 M 1 by means of four non-covalent bonding interactions and, in combination with the peculiar helical shape of the monomers, forms only homochiral dimers. 

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