Dissociation of Valine Cluster Cations
| Autor: | Paul Scheier, Siegfried Kollotzek, Lukas Tiefenthaler, Jaroslav Kočišek, Milan Ončák |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
010304 chemical physics Protonation 010402 general chemistry 01 natural sciences Dissociation (chemistry) Article 0104 chemical sciences Ion Amino acid chemistry.chemical_compound Crystallography Monomer chemistry Ab initio quantum chemistry methods 0103 physical sciences Mass spectrum Cluster (physics) Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry. a |
| ISSN: | 1520-5215 1089-5639 |
| Popis: | Independently of the preparation method, for cluster cations of aliphatic amino acids, the protonated form MnH+ is always the dominant species. This is a surprising fact considering that in the gas phase, they dissociate primarily by the loss of 45 Da, i.e., the loss of the carboxylic group. In the present study, we explore the dissociation dynamics of small valine cluster cations Mn+ and their protonated counterparts MnH+ via collision-induced dissociation experiments and ab initio calculations with the aim to elucidate the formation of MnH+-type cations from amino acid clusters. For the first time, we report the preparation of valine cluster cations Mn+ in laboratory conditions, using a technique of cluster ion assembly inside He droplets. We show that the Mn+ cations cooled down to He droplet temperature can dissociate to form both Mn-1H+ and [Mn-COOH]+ ions. With increasing internal energy, the Mn-1H+ formation channel becomes dominant. Mn-1H+ ions then fragment nearly exclusively by monomer loss, describing the high abundance of protonated clusters in the mass spectra of amino acid clusters. |
| Databáze: | OpenAIRE |
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