RETENTION OF FLUORINATED TRANSITION-METAL BETA-DIKETONATES IN GAS-CHROMATOGRAPHIC COLUMNS

Retention of the Al(III), V(III), Cr(III), Fe(III), Mn(III), Co(III) and Cu(II) derivatives of the β-diketones, 1,1,1-trifluoropentane-2,4-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, 1,1,1-trifluoro-5-methylhexane-2,4-dione, 1,1,1-trifluoro-5,5-dimethylhexane-2,4-dione, 1,1,1,3,3-pentafluoro-6,6-dimethylheptane-3,5-dione and 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione in chromatographic columns with various supports has been studied. Chemical effects due to the nature of the support, ligand and the metal ion probably contribute to the observed magnitude of the retention. Irreversability of the phenomenon is interpreted as arising from dissociation in the stationary phase and retention therein or to reaction at active sites on the support. Several mechanisms for these reactions are proposed. © 1979.