Research

Photo‐electron spectroscopy and photo‐electron circular dichroism of cold chiral anions

Photoelectron Circular Dichroism (PECD) is a method of chiral discrimination, which can aid in our fundamental understanding of electron dynamics and holds promise for future analytical techniques of chiral compounds. In PECD, irradiation of a non-racemic sample by circularly polarized light, resulting in the detachment of an electron, leads to a forward-backward asymmetry of the photoelectron angular distribution. This technique has significant advantages over other optical CD methods, such as absorption circular dichroism, as sensitivity to the molecular chirality can manifest within the electric-dipole approximation, bypassing the need for observation of weak interactions with a molecule’s magnetic moment. Anions can be mass selected and, as their electron binding energies are usually significantly lower compared to the ionization energies of neutral molecules, more common laser sources in the visible or UV spectral region can be used for the photodetachment. Thus, anion PECD spectroscopy may potentially evolve to a robust analytical tool for chiral discrimination of multicomponent gas-phase samples.

IR-UV spectroscopy for studying structure and dynamics of gas-phase clusters