Communication: Identification of daughter ions through their electronic spectroscopy at low temperature

International audienceWe present experimental results on photofragmentation of cold fragments issued from the photofragmentation of a cold parent ion. The cooling of the daughter ion at a few K allows its characterization not only through its fragmentation pattern but also through its well resolved electronic spectroscopy. This method is demonstrated on the photofragment resulting from the Ca-Cb bond rupture of protonated tyrosine. The analysis of the daughter ion (m/z 108) photofragmentation spectrum seems to be in agreement with the mechanism implying a proton transfer to the phenyl ring as the first step of the fragmentation mechanism of protonated tyrosine