Université de Fribourg

Synthesis and Stereochemical Properties of Chiral Square Complexes of Iron(II)

Bark, Thomas ; Zelewsky, Alexander von ; Rappoport, Dmitrij ; Neuburger, Markus ; Schaffner, Silvia ; Lacour, Jérôme ; Jodry, Jonathan

In: Chemistry - A European Journal, 2004, vol. 10(19), p. 4839-4845

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...

Université de Fribourg

Polymorph of dibenzo-24-crown-8 and its mercury complex

Crochet, Aurélien ; Kottelat, Emmanuel ; Fleury, Antoine ; Neuburger, Markus ; Fromm, Katharina M.

In: Zeitschrift für anorganische und allgemeine Chemie, 2011, vol. 637, no. 6, p. 672–675

Dibenzo-24-crown-8 is studied herein as a flexible ligand able to adopt different conformations, as well as for the complexation of mercury. The recrystallization of dibenzo-24-crown-8 (DB24C8) from dry THF gives a new polymorphic structure of this ligand. This new structure is described and compared to the literature compound. Additionally, coordination of this ligand to mercury iodide HgI₂ is...