Referenced in: none

Automatically associated channels: Kir2.3

Title: A photoionization investigation of small, homochiral clusters of glycidol using circularly polarized radiation and velocity map electron-ion coincidence imaging.

Authors: Ivan Powis, Steven Daly, Maurice Tia, Barbara Cunha de Miranda, Gustavo A Garcia, Laurent Nahon

Journal, date & volume: Phys Chem Chem Phys, 2013 Sep 30 , ,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/24077129

Abstract
A detailed study of the valence photoionization of small homochiral glycidol (C3O2H6) clusters is carried out with the help of circularly-polarized VUV synchrotron radiation by recording photoionization-based spectroscopic data detected by velocity map electron imaging with coincidence ion selection. We show that information on the stability of cationic as well as neutral chiral clusters can be obtained with enhanced sensitivity by examining the chiral fingerprint encapsulated in Photoelectron Circular Dichroism (PECD) spectra. In particular, by varying the clustering conditions we demonstrate that the PECD signal effectively carries the signature of the neutral precursor species, prior to any fragmentation of the ion, as may be inferred from the below-threshold monomer measurements (including ion imaging). Here the monomer's direct ionization channel is closed and the monomer ion hence must result exclusively as a fragment from dissociative ionization of the dimer (or higher) clusters. At higher photon energies, the mass-selection on the electron spectroscopy data, achieved through filtering the electron images in coincidence with selected ion masses, evidently succeeds in providing a degree of size-selection on the neutral clusters being ionized with, in particular, a clear differentiation of monomer and dimer PECD, showing the strong sensitivity of this chiroptical effect to the non-local long-range molecular potential.