High resolution photoelectron spectroscopy of clusters of Group V elements

High resolution HeI (580 angstrom) photoelectron spectra of As2, As4, and P4 were obtained with a newly-built high temperature molecular beam source. Vibrational structure was resolved in the photoelectron spectra of the three cluster species. The Jahn-Teller effect is discussed for the 2E and 2T2 states of P4+ and As4+. As a result of the Jahn-Teller effect, the 2E state splits into two bands, and the 2T2 state splits into three bands, in combination with the spin-orbit effect. It was observed that the ν2 normal vibrational mode was involved in the vibronic interaction of the 2E state, while both the ν2 and ν3 modes were active in the 2T2 state. 26 refs., 5 figs., 3 tabs