Binaphthol-strapped chiral bis (porphyrinato) cerium double-decker complexes

(R)-(+)- or (S)-(−)-1,1′-bi-2-naphthol (BINOL) was applied as a remote chiral auxiliary to connect the two facing porphyrin rings, resulting in the BINOL-strapped chiral bis(porphyrinato) cerium double-decker complexes (R)-/(S)-1 and (R)-/(S)-2, which were carefully characterized by a range of spectroscopic and electrochemical methods. Perfect mirror images were observed in their circular dichroism (CD) spectra with a negative sign in the Soret band for (R)-enantiomers and a positive sign for (S)-enantiomers, which suggests the C2-chirality of a BINOL strap is transcribed to the double-decker core as a defined chiral twist in the inter-porphyrin arrangement. Furthermore, the CD intensities of (R)-/(S)-1 are always larger than those of (R)-/(S)-2, indicating that the intramolecular chirality transfer efficiency can be finely tuned by changing the length of interlocking moieties.