Fragmentation reactions of singly and doubly protonated thiourea- and sugar-substituted cyclams and their transition-metal complexes
| Autor: | Holger Stephan, Thorsten Felder, Christoph A. Schalley, Anika Röhrich |
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| Rok vydání: | 2008 |
| Předmět: |
inorganic chemicals
Spectrometry Mass Electrospray Ionization Stereochemistry Electrospray ionization Lactams Macrocyclic Carbohydrates Thiourea Protonation Mass spectrometry Photochemistry Ion cyclotron resonance spectrometry Dissociation (chemistry) chemistry.chemical_compound Electron transfer Fragmentation (mass spectrometry) chemistry Cyclam Transition Elements Protons Spectroscopy |
| Zdroj: | Journal of mass spectrometry : JMS. 43(5) |
| ISSN: | 1076-5174 |
| Popis: | Cyclam macrocycles tetrasubstituted with amino-, thiourea-, and sugar-terminated side chains are ionized by electrospray ionization mass spectrometry (ESI-MS) as singly or doubly protonated species or as transition-metal complexes. Their fragmentation behavior is examined in a Fourier-transform ion-cyclotron-resonance (FT-ICR) mass spectrometer by collision-induced dissociation (CID) experiments. Typically, fragmentation occurs within the side chains through a number of different 1,2-elimination reactions irrespective of the absence or presence of a transition metal ion such as Co2+, Ni2+, or Zn2+. A remarkable exception is Cu2+, which induces ring cleavage reactions. This is traced back to an electron transfer from the cyclam nitrogen atoms to the Cu2+ ion. The electron transfer creates a cation-radical within the macrocycle, which induces typical fragmentation reactions such as α-cleavages that lead to fragmentation within the macrocycle. This interpretation is in line with fragmentation experiments on unsubstituted cyclam and its complexes. Copyright © 2008 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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