Progressive Stabilization of Zwitterionic Structures in [H(Ser)_2–8]⁺ Studied by Infrared Photodissociation Spectroscopy

Abstract

Does (Ser)2 have a neutral structure? How does the zwitterion evolve with an increasing cluster size of serine (Ser)? Infrared spectroscopic and mass-spectrometric analysis of [H(Ser)n]+ (n=2–8) shows progressive stabilization of the zwitterion with increasing cluster size, and the results of ab initio calculations based on density functional theory of [H(Ser)2]+ are also given (picture: a neutral structure; red O, blue N, gray C, white H).