For our study we chose a dodeca-substituted porphyrin P bearing four ammonium groups on the ortho-phenyl positions. Since the aryl groups with bulky ortho-substitution has limited rotation around the porphyrin-aryl C-C bond, four porphyrin P atropisomers (rotation restricted isomers, see Figure ) become separable with characteristic NMR profiles. In particular, we were interested in the α2β2 () atropisomer due to its recent application in the enantiomeric excess discrimination of chiral analytes (CSA) using NMR spectroscopic techniques. As we were unable to obtain the crystal structure of the corresponding adducts we used the α2ß2-P[SO4 2-][HSO4 -]4 crystal structure as a model. ). The macrocycle in P is highly distorted due to periinteractions between the β-ethyl and meso-aryl residues. To minimize the steric interactions of the peripheral substituents and to a smaller extent to minimize the electrostatic interactions between four core protons the porphyrin adopts overall a saddleshaped structure. Normal-structural decomposition (NSD) analysis of α2ß2-P[SO4 2-][HSO4 -]4 and solvated hexacationic porphyrin α2ß2-P showed a major saddle distortion (3.27 -3.92 Å) together with small contributions from ruffling, wave and dom deformations (Figure and Table ). As a result, two cavities are formed on both sides of the porphyrin (Figure ).