The continuous absorption spectra of alkyl iodides and alkyl bromides and their quantal interpretation.

In recent years a number of continuous absorption spectra of diatomic molecules have been examined in order to determine the potential energy-distance curves for the excited states. Gibson, Rice and Bayliss (1933) and Bayliss (1937) applied the methods of quantum mechanics to the chlorine and bromine spectra respectively and Stükelberg (1932) treated the oxygen continuum in a similar manner. The spectra of hydrogen bromide and iodide were analysed by Goodeve and Taylor (1935, 1936). The method of treatment has recently been extended and applied to the methyl bromide spectrum by Fink and Goodeve (1937). In the present paper, recently published measurements for methyl iodide (Porret and Goodeve 1937) are analysed and compared with new data for ethyl iodide. The spectra of ethyl and butyl bromides have been measured and compared with that of methyl bromide.