Chiral Recognition Of Optically Active Monoamines By A Serial Of M-phthalic Diamide-linked Zinc Bisporphyrinates

Exciton-coupled circular dichroism(ECCD) spectroscopy, as a more straightforward method, has provided a useful non-empirical method to determine absolute configuration. Bisporphyrin has been designed as a host of chiral recognition due to its strong absorption in UV-vis. For bisporphyrin systems, a lot of studies are focused on bidentate ligands. However for monodentate ligands, only limited systems can differentiate their enantiomers.So we have designed a serial of m-phthalic diamide-linked zinc bisporphyrinates([Zn2-1], [Zn2-2], [Zn2-3]), which can chiral recognize monoamines. In our study, we find the hosts can distinguish those two different types of chiral monoamines, alkyl and aryl substituents of chiral monoamines, by their induced CD signs. In order to figure out the mechanism of the results, UV-vis titration, 1H NMR and DFT calculations are used. Our studies reveal the bulkiness of substituents of monoamines play very important roles.