Finally, we examined the optical and chiroptical properties of the synthesized nanohoops ((S)/(R)-OH-[9]CPP) (Fig. and Supplementary Figs. 67 -74). The absorption spectra of (S)and (R)-OH- [9]CPP exhibit a broad absorption band reaching a maximum at around 330 nm with a molar absorption coefficient of ~1.1  10 5 M -1 cm -1 . Both enantiomers of the nanohoop are emissive and exhibit bands with two maxima at 452 and 473 nm, which are responsible for the distinct blue emission that is typical for symmetry-broken [9]CPP-type nanohoops (Fig. ). Electronic circular dichroism (ECD) spectra show the expected mirror-imaged spectra featuring pronounced Cotton effects thanks to the rigid conjugated architecture (Fig. ). The circularly polarized luminescence (CPL) spectrum of (R)-OH- [9]CPP manifests the same negative sign at higher energies as the circular dichroism spectra with a maximum of polarization at 432 nm with a glum value of -2.6•10 -3 . (S)-OH- [9]CPP exhibits very similar and mirror shape behavior but positive glum value of +2.8•10 -3 (Fig. ). Overall, the chiroptical properties fall into the useful and typical range for highly emissive conjugated macrocycles. We show that unusual selectivity and scope is observed in asymmetric transfer hydrogenations catalyzed by a BINOL phosphoric acid that is integrated into a shape-persistent CPP nanohoop.