Chiral recognition and chiral sensing using zinc porphyrin dimers

The chiral zinc porphyrin dimer linked by the (S)-NMe2 or (R)-2,2′-dimethoxy-1,1′-binaphthyl tightly binds diamines via a zinc–nitrogen coordinated ditopic interaction. In particular, the zinc porphyrin displays excellent enantioselectivity towards Lys. The D/L selectivity is determined to be 11–12 for the lysine derivatives. The achiral zinc porphyrin dimers linked by biphenyl unit exhibit a significantly induced CD in the Soret region in the presence of chiral diamines such as lysine amides and cystine diesters, indicating that the chirality of the amino acid derivatives can be monitored upon the complexation with the achiral zinc porphyrin dimer. These results conclude that the zinc porphyrin dimers linked by rigid spacers may be good receptors to discriminate two enantiomers or monitor the absolute configuration of a diamine.