Speaker
Description
Photoelectron Circular Dichroism (PECD) is a chiral optical effect that manifests in the angle-dependent photoemission of an electron upon irradiation of a chiral molecule by circularly polarized light. PECD can aid in our fundamental understanding of electron dynamics as this effect is acutely sensitive to the molecular state and electron emission conditions. The magnitude and sign of PECD can vary greatly depending on the emission channels linking the initial and final states of the molecule, the conformation of the molecule and its vibrational states, and the kinetic energy of the departing electron. This sensitivity is a double edge sword: PECD studies can offer a wealth of information, if one can disentangle the individual contributions to the overall measured PECD. The use of anions in PECD studies allows for pre-photodetachment mass selectivity and eliminates the need for X-ray based ionization sources or multiphoton ionization schemes. Furthermore, photodetachment from anions is a photoemission regime that has historically been understudied in conjunction with PECD studies. We provide an energy-resolved PECD signal for mass-selected deprotonated chiral anion of (R)-1-phenylethanol. The photoelectron spectrum of deprotonated 1-phenylethanol is clearly assigned to a single electronic transition of a single conformer, which allows for the straightforward investigation of the PECD dependence on the electron kinetic energy, as well as vibrational state of the molecule. The PECD of 1-phenylethanol was measured at different photon energies from 2.38 eV to 3.59 eV, showing a change of the resulting PECD value for a given transition with differing electron kinetic energies. If electron kinetic energy is held constant, the PECD effect at low electron kinetic energies is found to be dominated by a single vibrational mode.
