title: Vacuum ultraviolet photoionization study of gas phase vitamins A and B1 using aerosol thermodesorption and synchrotron radiation.
abstract: Gas-phase studies of biomolecules are often difficult to initiate because of the thermolability of these systems. Such studies are nevertheless important to determine fundamental intrinsic properties of the molecules. Here we present the valence shell photoionization of gas-phase vitamins A and B1 close to their ionization threshold. The study was performed by means of an aerosol thermodesorption source coupled to an electron/ion coincidence spectrometer and synchrotron radiation (SOLEIL facility, France). Ion yield curves were recorded for both molecules over a few electronvolt energy range and the threshold photoelectron spectrum was also obtained for vitamin A. Some fundamental properties were extracted for both ions such as adiabatic and the three first vertical ionization energies of retinol (IEad = 6.8 ± 0.2 eV and IEvert = 7.4, 8.3, and 9.2 eV) and dissociation appearance energies for the main fragment ions of vitamin B1. Analysis of the data was supported by ab initio calculations which show a very good agreement with the experimental observations.
authors.affiliation: Université Pierre et Marie Curie , IPCM/CSOB UMR 8232, 4, Place Jussieu BP 45, 75252 Paris, France.
authors.forename: Héloïse
authors.initials: H
authors.lastname: Dossmann
authors.forename: Adrián
authors.initials: A
authors.lastname: Schwarzenberg
authors.forename: Denis
authors.initials: D
authors.lastname: Lesage
authors.forename: Marie
authors.initials: M
authors.lastname: Pérot-Taillandier
authors.forename: Carlos
authors.initials: C
authors.lastname: Afonso
authors.forename: Barbara
authors.initials: B
authors.lastname: Cunha de Miranda
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Garcia
mesh_terms: D000336:Aerosols; D004583:Electrons; D005740:Gases / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D055668:Photochemical Processes; D017356:Synchrotrons; D013696:Temperature; D013816:Thermodynamics; D013831:Thiamine / Q000737:chemistry*; D014466:Ultraviolet Rays; D014618:Vacuum; D014801:Vitamin A / Q000737:chemistry*
chemical_list: D000336:Aerosols; D005740:Gases; D014801:Vitamin A; D013831:Thiamine