The Role of Amino Acid Esters and the Amide Group in the Chiral Induction Process by a Novel Monoamide-Linked Monozinc Bisporphyrinate

Crystallographic and Spectroscopic Studies of a Host-Guest Complex Consisting of a Novel Zinc Trisporphyrinate and a Chiral Monoamine

We have designed and synthesized a novel zinc trisporphyrinate with a benzene tricarboxamide as the linker. In the presence of a large excess of 1-phenylethylamine, single crystals of the corresponding 1:3 host-guest complex were obtained, which provide the crystallographic structure of a host-guest complex consisting of an achiral porphyrin and a chiral monoamine. The structure reveals the 1-phenylethylamines adopt the "inside" binding mode that is stabilized by intramolecular hydrogen bonds. The NH2 of the 1-phenylethylamine is involved in both coordination and hydrogen bonding interactions. Circular dichroism (CD) and ultraviolet-visible spectra revealed that the 1:3 host-guest complex is dominant in the presence of a large excess of 1-phenylethylamine. The crystal structure shows there are two diastereomers of the 1:3 host-guest complexes. Density functional theory and TDDFT calculations suggest that one of the diastereomers is more energetically favorable, which dominates the CD signals.

Discrimination between alkyl and aryl substituents of chiral monoamines by m-phthalic diamide-linked zinc bisporphyrinates

m-Phthalic diamide-linked zinc bisporphyrinates can not only determine the absolute configuration of monoamines but also distinguish between alkyl and aryl substituents of chiral monoamines.