Vacuum Ultraviolet Absorption and Photoelectron Spectra of Aliphatic Ketones

The vacuum ultraviolet absorption spectra down to 65000 cm−1 and Hel photoelectron spectra were measured for CH3CHO and RCOCH3 (R=CH3 to t-C4H9). Assignments of the absorption bands are proposed with the aid of photoelectron spectra and CNDO/2 type molecular orbital calculations. Special notice has been paid to the similarity of the vibrational structure between the lowest ionization potential bands of photoelectron spectra and the second bands of vacuum ultraviolet absorption spectra.