title: Magnetic coupling in enantiomerically pure trinuclear helicate-type complexes formed by hierarchical self-assembly.
abstract: Based on chiral, enantiomerically pure 7-[(S)-phenylethylurea]-8-hydroxyquinoline (1-H), trinuclear helicate-type complexes 2-5 are formed with divalent transition-metal cations. X-ray structural analyses reveal the connection of two monomeric complex units [M(1)(3)](-) (M=Zn, Mn, Co, Ni) by a central metal ion to form a "dimer". Due to the enantiopurity of the ligand, the complexes are obtained as pure enantiomers, resulting in pronounced circular dichroism (CD) spectra. Single-ion effects and intra- and intermolecular coupling are observed with dominating ferromagnetic coupling in the case of the cobalt(II) and nickel(II) and dominating antiferromagnetic coupling in the case of the manganese(II) complex.
authors.affiliation: Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany. markus.albrecht@oc.rwth-aachen.de
authors.forename: Markus
authors.initials: M
authors.lastname: Albrecht
authors.forename: Marcel
authors.initials: M
authors.lastname: Fiege
authors.forename: Paul
authors.initials: P
authors.lastname: Kögerler
authors.forename: Manfred
authors.initials: M
authors.lastname: Speldrich
authors.forename: Roland
authors.initials: R
authors.lastname: Fröhlich
authors.forename: Marianne
authors.initials: M
authors.lastname: Engeser