Rydberg transitions of aniline and N,N-diethylaniline

The absorption spectra of aniline and N,N-diethylaniline in the gaseous and condensed phases were measured in the 30 000-60 000 cm ^-1 region. The magnetic circular dichroism (MCD) spectra of these compounds in the gas phase and in solution were also measured in the region 30 000-49 000 cm ^-1. The MCD signals due to the Rydberg transitions were newly observed for N,N-diethylaniline. On the basis of these data, we demonstrated that in the region below 50 000 cm ^-1 the Rydberg transition bands appear at 47 180 cm ^-1 for aniline and at 36 520, 38 880, and 42 000 cm ^-1 for N,N-diethylaniline. Besides these, in the region higher than 50 000 cm ^-1, a number of Rydberg transition bands were observed for both compounds in the gaseous state. The observed Rydberg transition bands were analyzed with the aid of the Rydberg formula: they were assigned for aniline to the np- and nd-type series converging to the first and second ionization potentials, and for N,N-diethylaniline to the us- and two np-type series converging to the first ionization potential.