The adiabatic ionisation energy of CO₂

Abstract

The adiabatic ionization energy E I of CO 2 , corresponding to the interval between the X 1 Σ + g (v 1 , v 2 , v 3 = 0, 0, 0), J = 0 ground state of CO 2 and the X + 2 Π g,3/2 (0, 0, 0), J + = 3/2 ground state of CO + 2 has been determined to be E I = hc•111 112.29( 18) cm −1 by pulsed-fieldionization zero-kinetic-energy photoelectron spectroscopy of a low-pressure CO 2 gas sample at room temperature. The improved precision and accuracy compared to earlier values result from the use of a multipulse electric-field sequence for the selective ionization of high Rydberg states and the use of a stationary gas sample to suppress uncertainties from Doppler shifts.

Pulsed-ramped-field-ionization zero-kinetic-energy photoelectron spectroscopy: a methodological advance

“…[20][21][22] The CO 2 molecule is thus a benchmark molecule for high resolution photoionization studies and has been studied quite extensively. 18,23,[24][25][26][27][28] In Fig. 6, we present the experimental measurement of the X +2 P g,1/2 (v + = 0) ' X 1 S + g (v = 0) ionizing transition of CO 2 obtained with the procedure described in the present paper.…”