O. Hernandez, P. Pulay, P. Maître, B. Paizs
J. Am. Soc. Mass Spectrom. 1511 25 (2014). DOI

Travail réalisé sur le site de l’Université Paris Sud.

Abstract

Using quantum chemical calculations and infrared multiphoton dissociation (IRMPD) spectroscopy in the fingerprint and X-H stretching regions, we demonstrate here that the all-Ala b6 fragment ion features a macrocyclic structure with C2 symmetry. For this structure, the ionizing proton is equally shared by the Ala(1) and Ala(4) amide oxygens in a Zundel-type symmetric (X...H+...X) H-bond.