Laboratory-frame electron angular distributions: Probing the chemical environment through intramolecular electron scattering

Carbon $1s$ photoelectron asymmetry parameters β for the chlorinated and the methyl carbon atom of CH₃CH₂Cl, CH₃CHCl₂, and CH₃CCl₃ have been measured using synchrotron radiation in the 340--600 eV energy range. We provide experimental evidence that the intramolecular scattering strongly affects β values, even far from the ionization threshold. The results are in agreement with B-spline density functional theory calculations, making it possible to single out the behavior of the various continuum partial waves. We conclude that the intramolecular scattering makes electron angular distributions sensitive to the chemical environment, even in isolated gas phase molecules.