title: Absolute Asymmetric Synthesis: Viedma Ripening of [Co(bpy)3](2+) and Solvent-Free Oxidation to [Co(bpy)3](3.).
abstract: Syntheses of [Co(bpy)3](2+) yield racemic solutions because the Δ- and Λ-enantiomers are stereochemically labile. However, crystallization and attrition-enhanced deracemization can give homochiral crystal batches of either handedness in quantitative yield. Subsequently, solvent-free oxidation with bromine vapour fixes the chirality because [Co(bipy)3](3+) does not enantiomerize in solution at ambient temperature. This combination of Viedma ripening and the labile/inert Co(II)/Co(III) couple constitutes a convenient method of absolute asymmetric synthesis.
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg (Sweden).
authors.forename: Per Martin
authors.initials: PM
authors.lastname: Björemark
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg (Sweden).
authors.forename: Johan
authors.initials: J
authors.lastname: Jönsson
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg (Sweden). hson@chem.gu.se.
authors.forename: Mikael
authors.initials: M
authors.lastname: Håkansson
keywords: asymmetric synthesis; circular dichroism; cobalt; deracemization; structure elucidation