Operating with enantiopure 10CSA(S or R) four distinct scenarios with four different P atropisomers were observed and subsequently rationalized by the symmetry operations found in P (Figure ). In the α4-Pꞏ10CSA(S or R) complex, the inner core remains isochronous, due to the C2v point-group notation with a two-fold symmetry axis and two mirror planes passing through the pyrroles. The identical situation previously reported by Hill and coworkers in Bz2oxP pinpoints the interactions with inner N-H, however, without the e.e. discrimination due to the C2v symmetry (Figure ). The 22-P atropisomer with Cs symmetry features a single well-defined mirror plane dividing two pyrrolic units which preserve its achiral nature, hence allowing it to be classified as pro-CSA. The lack of other symmetry elements in 22-P allows the N-H protons to become anisochronous in a chiral environment, making chiral discrimination possible (with the highest magnitude of splitting (max) of 0.653 ppm at 100% e.e.) (Figure ). The α3β-P atropisomer belongs to the C1 point-group, as it contains no symmetry elements, making the system chiral. Thus, eight signals are observed with enantiopure 10CSA due to diastereomer formation (SS-and SR-or RR-and RS-) (Figure ). While the e.e. detection is possible with α3β-P (Figure ), the practical use of such system falls short mainly due to three dominating factors: 1) the high number of inner core system signals hampers direct e.e. interpretation; 2) the magnitude of max (~0.39 ppm) is lowest of the three atropisomers with inner core splitting making it the least sensitive system; 3) the concentration of α3β-P is required to be significantly higher than that of other systems due to a large number of resonance signals and their comparatively lower intensities. On the other hand, αβαβ-P which belongs to the S4 point group has four equivalent protons located in the principal axis. While it has no mirror planes, the inversion center situated between the pyrrole units allows the inner core protons to split in equal proportions (above and below the plane) upon interaction with a chiral analyte. A single isochronous N-H signal of αβαβ-P-10CSA(S or R) becomes anisochronous, with max (0.520 ppm) comparable to the α2β2-Pꞏ10CSA(S or R) system (0.653 ppm). While a singular inner core proton splitting is an attractive feature, the practicality of such a system in the e.e. detection is challenging, mainly due to the low atropisomeric rotational barrier, which leads to the formation of other atropisomers at room temperature and low abundancy (only 1/8 obtained from statistical mixtures) in comparison to other P rotamers. Since 22-P displayed the highest ∆σmax value compared to other P atropisomeric species (Figure ), in-depth chirality determination studies listed below were carried out with this receptor system.