Unimolecular reactivity of uracil–Cu$^{2+}$ complexes in the gas phase - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue ChemPhysChem Année : 2007

Unimolecular reactivity of uracil–Cu$^{2+}$ complexes in the gas phase

Résumé

The gas‐phase interaction of copper(II) ions with uracil are studied by means of mass spectrometry and B3LYP/6‐311+G(2df,2p)//B3LYP/6‐31G(d) calculations. Positive‐ion electrospray spectra show that the reaction of uracil with copper(II) gives rise to singly charged species, whereby the [Cu(uracil-H)]+ complex is the most intense ion in the spectra at low concentration. Mass spectrometry/mass spectrometry (MS/MS) experiments show that the loss of HNCO and NCO are the dominant fragmentation processes, accompanied by a minor loss of CO. A systematic study of the spectra obtained with different labeled species, namely, 2‐13C‐ (m /z 175), 2‐13C,1,3‐15N2‐ (m /z 177) and 3‐15N‐uracil (m /z 175), concludes unambiguously that both the loss of HNCO and NCO involve exclusively C2 and N3, whereas only C4 is involved in the loss of CO. Suitable mechanisms for these fragmentation processes are proposed through a theoretical survey of the corresponding potential energy surface. In these mechanisms, π complexes, which lie high in energy with respect to the global minimum, play a significant role in the loss of NCO; this explains why both products, HNCO and NCO involve the same atoms of the ring.
Fichier principal
Vignette du fichier
Cu-uracil_revised_HAL.pdf (1.21 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-00123204 , version 1 (31-01-2023)

Identifiants

Citer

Al Mokhtar Lamsabhi, Manuel Alcamí, Otilia Mó, Manuel Yáñez, Jeanine Tortajada, et al.. Unimolecular reactivity of uracil–Cu$^{2+}$ complexes in the gas phase. ChemPhysChem, 2007, 8 (1), pp.181-187. ⟨10.1002/cphc.200600399⟩. ⟨hal-00123204⟩

Collections

CEA CNRS UNIV-EVRY
114 Consultations
15 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More