1 Chiral Asymmetry in the Angle-Resolved O and C

2 We present the first measurements of a photoelectron circular dichroism in photoionization from O and 1s core levels of the R-enantiomer of glycidol (C3H6O2) in the gas phase. This dichroism emerges from a forward-backward asymmetry in the angular distribution of electrons created on ionization with circularly polarised synchrotron radiation and is already fully present in the pure electric dipole approximation. Asymmetry factors obtained for the core levels in this study range up to a few percent, but it is likely that these values are limited by a failure to resolve photoemission from individual atomic sites. Theoretical modelling is provided to examine potential differences between these alternative atomic photoemission sites, and between different conformational structures of glycidol. The calculated chiral angular distribution parameters that support the circular dichroism display a much enhanced sensitivity to the molecular conformation compared to the conventional photoionization cross-section and the β-parameter. Likely conformer structures can be suggested after comparison with the experiment. 1