title: Metal complexes of a biconcave porphyrin with D4-structure--versatile chiral shift agents.
abstract: Representative metal complexes of a biconcave D4-symmetric porphyrin were synthesised by metalion insertion into the porphyrin ligand 1. The NMR spectra suggested D4-symmetry for the ZnII and dioxo-RuVI complexes of 1 and C4-symmetry for the unsymmetrically ligated RuII and RhIII complexes. Metal complexes of 1 proved to be versatile chiral 1H NMR shift agents for a broad spectrum of organic amines, alcohols, carboxylic acids, esters, nitriles and nonpolar fullerene derivatives. A practical analysis of chiral substrates with 1 covers enantiomeric excesses beyond 99%. An X-ray structure of (1:1)-cocrystals of an achiral, biconcave CoII porphyrinate and C60 provided the first detailed insights into the structure of such a biconcave metallo-porphyrinate. It also showed remarkable packing of the carbon sphere against the main concave units of the porphyrin and gave clues about the relevant interactions between biconcave porphyrins and fullerenes.
authors.affiliation: Institut für Organische Chemie, Universität Innsbruck, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Schwenninger
authors.forename: J
authors.initials: J
authors.lastname: Schlögl
authors.forename: J
authors.initials: J
authors.lastname: Maynollo
authors.forename: K
authors.initials: K
authors.lastname: Gruber
authors.forename: P
authors.initials: P
authors.lastname: Ochsenbein
authors.forename: H B
authors.initials: HB
authors.lastname: Bürgi
authors.forename: R
authors.initials: R
authors.lastname: Konrat
authors.forename: B
authors.initials: B
authors.lastname: Kräutler