Chiral Recognition Of Amino Acid Esters By Novel Mononuclear Or Dinuclear Bisporphyrinates

Many biomolecules are chiral molecules, so the recognition of chiral molecules andelucidation of their chiral recognition mechanism are crucial to supramolecular chemistry.Porphyrins, especially bisporphyrins, have been widely applied for chiral recognition. Inmost current bisporphyrin systems, the guest molecules function as bidentate ligands. Wehave recently reported a new amide-linked bisporphyrin which have the chiral recognitionability for monodentate ligands. Herein, we have further designed and synthesized newmononuclear and dinuclear bisporphyrinates and expect to elucidate their chiral recognitionmechanism.In this thesis, we have designed and synthesized three bisporphyrinates containingamide groups on the basis of mono o-aminophenyl substituted porphyrin and mono p-carboxyphenyl substituted porphyrin,[ZnP1-ZnP2](compound1),[ZnP1-P2](compound2),[NiP1-ZnP2](compound3).With these three porphyrinates as hosts, we have studied their chiral recognitionability for amnio acid esters, Only Compound1and2have exhibited strong chiralrecognition abilities for amino acid esters. It suggests that amino acid esters function asmonodentate ligands and the amide group is possible involved in hydrogen bonds in thechiral recognition process. We have further investigated the interactions between theporphyrin hosts and amino acid esters by UV-vis spectra and1H NMR. Based on UV-visspectra and1H NMR, we have done DFT/TDDFT calculations between compound2andL-Leu-OEt, which provide the optimized structure of the host-guest complex. Thecalculated CD signal is consistent with the experiment result. The origination of CD signalhas been explained through molecular orbital transitions.