Structure of the low-lying electronic states of from rotationally resolved photoelectron spectra

Abstract

Pulsed-field-ionisation zero-kinetic-energy (PFI-ZEKE) photoelectron spectra of 132Xe2 have been measured in the range of 90100 to 108400 cm−1, where the lowest electronic states of the cation are located. A (1 + 1′) resonance-enhanced two-photon excitation scheme via selected rovibrational levels of the C 0 state of 132Xe2 was used to resolve the rotational structure of several vibrational levels of the I(1/2u), I(3/2g), I(3/2u) and II(1/2u) electronic states. For the ground cationic state even the Ω-doubling was resolved. A vibrational progression belonging to the II(1/2g) electronic state has been observed for the first time proving that the II(1/2g) state is bound. The analysis of the rotational structure, performed in Hund's angular momentum coupling case (c), enabled the determination of the equilibrium internuclear distances and the dissociation energies of the I(1/2u), I(3/2g), I(3/2u) and II(1/2u) states of Xe and the corresponding adiabatic ionisation energies.