Control of Ultrafast XUV-Induced Dynamics in Amino Acids by Halogen Functionalization

Halogenated compounds play an important role in a broad variety of natural and biological processes, such as the enzymatic activity or the biosynthesis of essential metabolites [1]. Halogenation of amino acids is thus a powerful strategy to engineer peptides' structure and function [2]. In this context, the study of the interaction of light with halogenated amino acids (HAAs) is of primary importance: at molecular level, halogenation changes the potential energy surfaces of the amino acid, greatly affecting all elementary processes triggered by the absorption of light, such as electron transport mechanisms governing biological signals and/or leading to photo-induced damage. Here, we investigate the ultrafast dynamics initiated by a short train of extreme-ultraviolet (XUV) attosecond pulses centred around 40 eV and probed by a 5-fs near-infrared (NIR) pulse in halophenylalanines (HP), revealing strong evidence of the role of the halogen in the ultrafast dynamics following XUV ionization.