Hexaphyrin-cyclodextrin hybrids: Getting larger, getting confused

The diversity of hexaphyrin-cyclodextrin hybrids (HCD), previously formed from the covalent assembly regular hexaphyrin and [Formula: see text]-cyclodextrin subunits, has been increased following two main directions: enlarging confined space provided by cyclodextrin tuning N-core aiming at bimetallic complexes. larger unit was selectively functionalized with aldehyde linkers on its primary rim which were further reacted 2 eq. pentafluorophenyl tripyrrane in acidic conditions, followed DDQ oxidation. Doubly-linked HCD obtained structural variations macrocycles depending MSA concentration (2 vs. 200 mM) producing either ([26] rectangular/[28] Möbius) or doubly N-confused dioxo rectangular) scaffolds. For latter, isomers isolated featuring mirror transoid skeletons long-side meso-linking patterns, giving rise to planar chirality origin intense opposite electronic circular dichroism (ECD) spectra. Zn(II) complexation then investigated leading findings. (i) [28] Möbius afforded a mixture monometallic complexes presence acac ligand. ECD spectroscopy indicated transfer favoring text] twist, but that arising narrower congener ([Formula: twist favored). (ii) Owing N 3 O coordination boxes, dissymmetric readily HCDs through positive cooperative process. Both metal centers bind DMAP ligand axial positions, is interest for