Until quite recently infrared absorption spectroscopy had few applications in analytical chemistry. The development of the potassium bromide disc technique1 has, however, improved the position, MAGEE AND AL-KAY&C useci the technique in the systematic identification of fourteen anions, and later for the determination of rhenium and technetium3. In both investigations tetraphenyl~sonium. chloride was used as the precipitating agent for the polyatomic anions ancl the compounds formed showed strong, sharp absorption bands in the region 9-13 p, which were assignable to metal-oxygen stretching frequencies. In the present work a reagent was sought which, in the complex formed, preserved the metal-oxygen band; a further criterion was that the reagent should show an absorption spectrum having as few strong absorption bands as possible,particularly in the region g-13 p. Among the reagents invcstigatcd &hydroxyquinoline possessed the necessary requirements. Little previous work has been carried out with this reagent in the infrared region of the spectrum. CHARLES et al.4 and PHILLIPS AND D~~nGstudied the infrared spectra of a number of metal 8-~1S'ctroxyquino~natcs and came to the conclusion that a band in the region of II p was assignable to the metal-oxygen stretching frequency. STONE" examined the infrared spectra of bismuth and mabmesium S-hydroxyquinolinates. The only infrared work of a quantitative nature using 8-hydroxyquinoline is that of MAGEE AND MARTIN who used the reagent for the determination of niobium and tantalum. In the present work the 8-hydroxyquinolinates of chromium, vanadium, molybdenum and tungsten were examined by the infrared technique with a view to their use in the qualitative and quantitative analysis of the elements. The results of these investigations are reported below.
EXPERIMEXTAL
The 8-hydroxyquinolinates of chromium, vanadium, molybdenum and tungsten were prepared as follows.
To the aqueous solution of vanadium or chromium, 5 g of ammoniumacetate were Anni, Chim. Acin,ag (rg63) 5x7-523