Photoabsorption and Photoelectron-Yield Spectra of Polypeptides in the Vacuum-uv Region

The photoabsorption spectra and the photoelectron-yield spectra in the vacuum-uv region between 1050 and 2400 A have been measured for the aliphatic homopolypeptide films poly(glycine), poly(L-alanine), and poly(L-valine). By comparing the photoabsorption spectra with the photoelectron-yield spectra, the existence of highly excited states at excitation energies above the first ionization potentials in these polypeptides is conjectured. Implications of these highly excited states are discussed in connection with the concept of the superexcited states in macromolecules such as polypeptides.