Stereochemistry and Solid-State Structure of an Intrinsically Chiral Meso-Patterned Porphyrin: Case Study by NMR and Single-Crystal X‑ray Diffraction Analysis

A C₁-symmerical meso-substituted ABCD-type porphyrin, [5-phenyl-10-(2-hydroxynaphthyl)-15-(4-hydroxyphenyl)­porphyrinato]­zinc­(II) (1), has been synthesized and characterized. The molecular structure of 1 has been determined by single-crystal X-ray diffraction analysis. The complex 1 crystallizes in a triclinic system with one pair of enantiomeric molecules per unit cell. Resolution of the racemic mixture has been achieved by chiral HPLC techniques. In particular, the absolute configurations of the enantiomers have been assigned from NMR spectroscopic analysis with l-Phe-OMe as the chiral solvating agent (CSA). The assignments have also been unambiguously confirmed by single-crystal X-ray diffraction analysis. The present results suggest that the CSA–NMR anisotropy strategy is applicable for the stereochemistry determination of chiral host–guest complexes with multiple intermolecular interactions. In addition, the multiple intermolecular interactions between the enantiomerically pure porphyrin S-1 and l-Phe-OMe are proved in the solid state by single-crystal X-ray diffraction analysis.