The Gas Chromatography of β-Diketonates

Abstract

Abstract Since the initial studies of James and Martin1,2 gas chromatography has revolutionized separations in organic and biochemistry. The development of the gas chromatography of metallic species has been relatively slow in coming; however, the inherent advantages of extraordinary sensitivity, speed and ease of separating mixtures of closely related compounds, has promoted a recent surge of interest in the technique. In general, gas chromatographs are not conveniently operated at temperatures in excess of 350° C. This temperature requirement places severe limitations on the types of inorganic compounds that can be chromatographed. In most, but not all cases, the metal complex must exhibit avapor pressure of 0.1 to 1 mm of mercury in order to have a reasonable rate of gas-phase migration through the column3. To meet the requirement, the complexes must be unusually volatile and thermally stable in the chromatographic column. Metal compounds of suitable volatility are limited in number and include metal alklys, metal alkoxides, metal carbonyls, metal hydrides, metal halides, π-bonded metal complexes and β-diketonates. Furthermore, the compounds must be formed in quantitative yield to be of practical analytical utility. The metal halides and the metal β-diketonates are the only two of the above which meet all these requirements.