Configurational isomerism in oxovanadium(IV) complexes

Two pairs of enantiomeric oxovanadium(IV) complexes of the fluorinated Schiff base 1,2-propylenebis(trifluoroacetylacetoneimine) were separated chromatographically and the absolute configurations tentatively assigned. The complexes were found to be stable to diastereoisomeric conversion about the carbon chiral centre at 200°C but were sensitive to such conversion about the oxovanadium(IV) chiral centre at considerably lower temperatures. Moisture and traces of free ligand appear to hasten this process.