Unusual hydroxyl migration in the fragmentation of β-alanine dication in the gas phase

Dariusz Grzegorz Piekarski (1) , Rudy Delaunay (2) , Sylvain Maclot (2) , Lamri Adoui (2) , Fernando Martín (1) , Manuel Alcamí (1) , Bernd A. Huber (2) , Patrick Rousseau (2) , Alicja Domaracka (2) , Sergio Díaz-Tendero (1)

1 Departamento de Qímica, Módulo 13, Universidad Autónoma de Madrid
2 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique

We present a combined experimental and theoretical study of the fragmentation of doubly positively charged β-alanine molecules in the gas phase. The dissociation of the produced dicationic molecules, induced by low-energy ion collisions, is analysed by coincidence mass spectrometric techniques; the coupling with ab initio molecular dynamics simulations allows rationalisation of the experimental observations. The present strategy gives deeper insights into the chemical mechanisms of multiply charged amino acids in the gas phase. In the case of the β-alanine dication, in addition to the expected Coulomb explosion and hydrogen migration processes, we have found evidence of hydroxyl-group migration, which leads to unusual fragmentation products, such as hydroxymethyl cation, and is necessary to explain some of the observed dominant channels.

Mots clés: Biomolecules; Amino Acid; Fragmentation; Collisions of ions and atomic/molecular targets

Domaines: Agrégats Moléculaires et Atomiques [physics.atm-clus]; Chimie-Physique [physics.chem-ph]

Dariusz Grzegorz Piekarski, Rudy Delaunay, Sylvain Maclot, Lamri Adoui, Fernando Martín, et al.. Unusual hydroxyl migration in the fragmentation of β-alanine dication in the gas phase. Physical Chemistry Chemical Physics, 2015, 17 (26), pp.16767-16778. ⟨10.1039/C5CP01628B⟩. ⟨hal-01215199⟩