Ground‐State Photoelectron Circular Dichroism of Methyl p‐Tolyl Sulfoxide by Single‐Photon Ionisation from a Table‐Top Source

Abstract

Single‐photon ionisation of enantiopure methyl p‐tolyl sulfoxide by circularly polarised light at 133 nm shows remarkably strong photoelectron circular dichroism (PECD), which has been measured in a velocity‐map‐imaging spectrometer. Both enantiomers were measured, each showing a PECD of a similar magnitude (ca. 25 %). These experiments were carried out with a tabletop high‐harmonic source with a photon energy of 9.3 eV, capable of ionising the electronic ground state of most organic and inorganic molecules. Ab‐initio scattering calculations provide a theoretical value of the expected chiral asymmetry parameter, and agree very well with the measured values once orbital mixing via configuration interaction in the cation is taken into account. This study demonstrates a simple photoionisation scheme that can be readily applied to study the time‐resolved PECD of photochemical reactions and suggests a pronounced sensitivity of PECD to electronic configuration interaction in the cation.

Ultrafast Imaging of the Jahn–Teller Topography in Carbon Tetrachloride

“…Our calculations predict that the 4p-Rydberg state manifold should be strongly configurationally mixed, with significant contributions from n Cl ( t 2 ) → 4s, and n Cl ( e ) → σ*. Consequently, this technique is experimentally sensitive to the configuration interaction involved in the excitation process, as we project onto three cation states with different localized holes, in similarity with recent findings of the sensitivity of PECD to configuration mixing …”

“…Consequently, this technique is experimentally sensitive to the configuration interaction involved in the excitation process, as we project onto three cation states with different localized holes, in similarity with recent findings of the sensitivity of PECD to configuration mixing. 47 The raw pump−probe TRPES is shown in Figure 1A, where the side panel contains a line-out of the photoelectron spectrum at 40 fs where each feature is maximal, and the top panel shows the integration of the signal over all time delays, fitted to a monoexponential model:…”

Investigation of photoelectron elliptical dichroism for chiral analysis

“…These include microwave three wave mixing, 1–4 Coulomb explosion imaging, 5–7 along with photoion circular dichroism (PICD) 8–17 and photoelectron circular dichroism (PECD). 12,13,18–62…”