B. Wenclawiak, R. Barkley, E. Williams
Dec 11, 1985
Citations
0
Influential Citations
10
Citations
Journal
Journal of Chromatography A
Abstract
Abstract A number of metal chelates with the anion of the recently synthesized ligand, 2,2,7-trimethyloctane-3,5-dione (Htod) have been investigated for their use in gas and liquid chromatographic separations of transition metals. Cr(tod)3 shows extraordinary stability in gas chromatographic columns at temperatures high enough to produce reasonably rapid elution. Cr(tod)3 and Co(tod)3 form geometrical isomers, which can be separated on a 5-μm particle size, reversed-phase (RP), surface-bonded silica analytical high-performance liquid chromatographic (HPLC) column with acetonitrile and water as eluents, on a normal-phase column, and by thin-layer chromatography (TLC) and HPTLC with hexane and methylene chloride. The metal chelates and the isomers of the more stereochemically rigid complexes have been characterized by thermogravimetric analysis, mass spectrometry, and, in the case of the diamagnetic Co(tod)3 by nuclear magnetic resonance spectrometry. Additionally, the separation of all of the geometrical isomers in a mixture of Cr(tfa)3, Cr(fod)3 and Cr(tod)3 was accomplished in a single RPLC experiment. (Abbreviations: Htfa 1,1,1-trifluoro-2,4-heptanedione; Hfod 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione.)