region 190-210 mjA was determined by Dr C. von Planta (Hoffmann-La Roche and Co., Basle) using a vacuum grating spectrometer as described by Planta (1962). Infrared-absorption spectra were recorded by a Perkin-Elmer Infracord (model 137) spectrometer. The highresolution spectra were obtained by Dr C. H. Steele of the Thornton Research Laboratories, Shell, Ellesmere Port, Cheshire, with a Grubb-Parsons double-beam grating spectrometer (model GS 2). Samples were examined as films between NaCl plates whenever possible. Materials of high melting point were studied as KBr disks.
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