Spectroscopic characterization and potential energy functions of the six low-lying electronic states of ArKr⁺

Abstract

Pulsed-field-ionization zero-kinetic-energy (PFI-ZEKE) photoelectron spectra of ArKr have been recorded in the wavenumber range 108,000-118,000 cm À1 using a 1 þ 1 0 two-photon resonant excitation scheme from the ground X 0 þ state of ArKr via selected intermediate states located just below the Ar( 1 S 0 ) þ Kr([5p[1/2] 0 ) dissociation limit. The positions of ionic vibrational levels with quantum numbers from 1 to 30, from 0 to 8 and from 0 to 6 were determined for the X(1/2), A 1 (3/2) and A 2 (1/2) states, respectively. The assignment of absolute vibrational quantum numbers of the ionic states was derived from the isotopic shifts of the spectral lines. Combining these data with literature data on the B(1/2) ! X(1/2), C 1 (3/2) ! A 1 (3/2) and C 2 (1/2) ! A 2 (1/2) band systems of ArKr þ enabled the derivation of potential energy functions for the lowest six electronic states of ArKr þ using a global potential model that includes the effects of the spin-orbit, charge-exchange and long-range interactions.

Rotationally resolved PFI-ZEKE photoelectron spectroscopic study of the low-lying electronic states of ArXe+

“…To account for the weak observed J = +5/2 transitions one needs to go beyond the orbital approximation and use l instead of l o in Eq. (11). The D 0 + state possesses 6pπ [A 1 3/2] character so that the overall intensity results from two contributions, one with l = 0 in Eq.…”

“…At large internuclear distances, the positive charge is localized on one of the rare-gas atoms, but, at short range, the charge is partially transferred to the other atom so that the states are of mixed A 2 and D 2 character and the states of mixed B 2 and C 2 character. 7,[9][10][11] The rare-gas dimer ions are prototypical systems to study charge-transfer processes in the presence of spin-orbit interactions. 12,13 The knowledge of their potential-energy functions and spectroscopic properties is also relevant to understanding the electronic spectrum of the neutral rare-gas dimers.…”

Interactions of rare gas cations with lighter rare gas atoms

“…Threshold photoelectron-photoion coincidence (TPEPICO) spectra have also yielded information on the lower cationic levels for KrAr 24 , Xe-Kr 25 , and Xe-Ar. 26 By far the most detailed information, however, has come from recent zero-kinetic energy (ZEKE) spectroscopic studies by Merkt's group, who have tackled Xe + -Kr, 27 Kr + -Ar, 28 and Xe + -Ar. 29 Reference and comparison to the results of these experimental results will be made below.…”