title: Synthesis and stereochemical properties of chiral square complexes of iron(II).
abstract: The hexadentate, and ditopic ligand 2,5-bis([2,2']bipyridin-6-yl)pyrazine yields a chiral, tetrameric, square-shaped, self-assembled species upon complexation with Fe2+ ions. The racemate of this complex was resolved with antimonyl tatrate as the chiral auxiliary. The purity of the enantiomer was determined by NMR spectroscopy, by using a chiral, diamagnetic shift reagent, and by circular dichroism (CD). The CD spectrum was also calculated by time-dependent density functional theory, and the correlation that was found between CD spectrum and configuration was confirmed by X-ray cristallography. When a "chiralised" version of the ligand was used instead, the corresponding iron complex was obtained in diastereomerically pure form.
authors.affiliation: Department of Chemistry, University of Fribourg, Pérolles, 1700 Fribourg, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bark
authors.forename: Alexander
authors.initials: A
authors.lastname: von Zelewsky
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Rappoport
authors.forename: Markus
authors.initials: M
authors.lastname: Neuburger
authors.forename: Silvia
authors.initials: S
authors.lastname: Schaffner
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lacour
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jodry