Ionization and Photofragmentation of Isolated Metalloporphyrin Cations Investigated by VUV Action Spectroscopy - Université Claude Bernard Lyon 1 Accéder directement au contenu
Article Dans Une Revue Chemistry - A European Journal Année : 2021

Ionization and Photofragmentation of Isolated Metalloporphyrin Cations Investigated by VUV Action Spectroscopy

Résumé

We investigated the photoionization and fragmentation of isolated metal protoporphyrin IX cations (MPPIX+ with M=Fe, Co, Zn) by means of vacuum-ultraviolet (VUV) action spectroscopy in the energy range of 8.5-35 eV. Experiments were carried out in the gas phase by interfacing an electrospray ionization tandem mass spectrometer with a synchrotron beamline. The mass spectra and partial ion yields show that photoexcitation of the precursor ions predominantly leads to (CH2COOH)-C-. radical side-chain losses of the macrocycle with additional methyl radical ((CH3)-C-.) side-chain losses. Ionization, in contrast, leads to the formation of the intact ionized precursor and various doubly charged fragments which are mostly due to side-chain cleavages. Although statistical fragmentation dominates, we found evidence for non-statistical processes such as new fragments involving for example single and double H2O losses, indicating that different relaxation mechanisms are at play upon photoionization compared to photoexcitation. The measured ionization energies were 9.6 +/- 0.2 eV, 9.4 +/- 0.2 eV and 9.6 +/- 0.2 eV for FePPIX+, CoPPIX+ and ZnPPIX+, respectively.
Fichier principal
Vignette du fichier
chem.202101515.pdf (1.03 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Licence : CC BY - Paternité

Dates et versions

hal-03295602 , version 1 (04-10-2021)

Identifiants

Citer

Kaja Schubert, Lucas Schwob, Simon Dörner, Marion Girod, Luke Macaleese, et al.. Ionization and Photofragmentation of Isolated Metalloporphyrin Cations Investigated by VUV Action Spectroscopy. Chemistry - A European Journal, 2021, 27 (48), pp.12371-12379. ⟨10.1002/chem.202101515⟩. ⟨hal-03295602⟩
70 Consultations
25 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More