Collision-induced dissociation of [UVI O2 (ClO4 )]+ revisited: Production of [UVI O2 (Cl)]+ and subsequent hydrolysis to create [UVI O2 (OH)]

Irena J Tatosian; Anna C Iacovino; Michael J Van Stipdonk

doi:10.1002/rcm.8135

Collision-induced dissociation of [U^VI O₂ (ClO₄ )]⁺ revisited: Production of [U^VI O₂ (Cl)]⁺ and subsequent hydrolysis to create [U^VI O₂ (OH)]

Rapid Commun Mass Spectrom. 2018 Jul 15;32(13):1085-1091. doi: 10.1002/rcm.8135. Epub 2018 May 27.

Authors

Irena J Tatosian¹, Anna C Iacovino¹, Michael J Van Stipdonk¹

Affiliation

¹ Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA.

PMID: 29645301
DOI: 10.1002/rcm.8135

Abstract

Rationale: In a previous study [Rapid Commun Mass Spectrom. 2004;18:3028-3034], collision-induced dissociation (CID) of [U^VI O₂ (ClO₄ )]⁺ appeared to be influenced by the high levels of background H₂ O in a quadrupole ion trap. The CID of the same species was re-examined here with the goal of determining whether additional, previously obscured dissociation pathways would be revealed under conditions in which the level of background H₂ O was lower.

Methods: Water- and methanol-coordinated [U^VI O₂ (ClO₄ )]⁺ precursor ions were generated by electrospray ionization. Multiple-stage tandem mass spectrometry (MSⁿ ) for CID and ion-molecule reaction (IMR) studies was performed using a linear ion trap mass spectrometer.

Results: Under conditions of low background H₂ O, CID of [U^VI O₂ (ClO₄ )]⁺ generates [U^VI O₂ (Cl)]⁺ , presumably by elimination of two O₂ molecules. Using low isolation/reaction times, we found that [U^VI O₂ (Cl)]⁺ will undergo an IMR with H₂ O to generate [U^VI O₂ (OH)]⁺ .

Conclusions: With lower levels of background H₂ O, CID experiments reveal that the intrinsic dissociation pathway for [U^VI O₂ (ClO₄ )]⁺ leads to [U^VI O₂ (Cl)]⁺ , apparently by loss of two O₂ molecules. We propose that the results reported in the earlier CID study reflected a two-step process: initial formation of [U^VI O₂ (Cl)]⁺ by CID, followed by a very rapid hydrolysis reaction to leave [U^VI O₂ (OH)]⁺ .