Reactions of gas-phase uranyl formate/acetate anions: reduction of carboxylate ligands to aldehydes by intra-complex hydride attack.

In a previous study, electrospray ionization, collision-induced dissociation (CID), and gas-phase ion-molecule reactions were used to create and characterize ions derived from homogeneous precursors composed of a uranyl cation (UO) coordinated by either formate or acetate ligands [E. Perez, C. Hanley, S.

Reactions of Atomic Thorium and Uranium Cations with SF Studied by Guided Ion Beam Tandem Mass Spectrometry.

The fundamental chemistry of the thorium and uranium fluorides continues to be an area of interest because of the use of thorium and uranium fluoride compounds in nuclear fuel systems. Here, we study the reaction of thorium cations with sulfur hexafluoride for the first time and revisit the reaction of uranium cations with sulfur hexafluoride. By using guided ion beam tandem mass spectrometry, we explore the reaction pathways that become accessible well above thermal energies ( ∼ 0.

Formation and hydrolysis of gas-phase [UO (R)] : R═CH , CH CH , CH═CH , and C H.

The goals of the present study were (a) to create positively charged organo-uranyl complexes with general formula [UO (R)] (eg, R═CH and CH CH ) by decarboxylation of [UO (O C─R)] precursors and (b) to identify the pathways by which the complexes, if formed, dissociate by collisional activation or otherwise react when exposed to gas-phase H O. Collision-induced dissociation (CID) of both [UO (O C─CH )] and [UO (O C─CH CH )] causes H transfer and elimination of a ketene to leave [UO (OH)] . However, CID of the alkoxides [UO (OCH CH )] and [UO (OCH CH CH )] produced [UO (CH )] and [UO (CH CH )] , respectively.

Gas-Phase Deconstruction of UO: Mass Spectrometry Evidence for Generation of [OUCH] by Collision-Induced Dissociation of [UO(C≡CH)].

Because of the high stability and inertness of the U=O bonds, activation and/or functionalization of UO and UO remain challenging tasks. We show here that collision-induced dissociation (CID) of the uranyl-propiolate cation, [UO(OC-C≡CH)], can be used to prepare [UO(C≡CH)] in the gas phase by decarboxylation. Remarkably, CID of [UO(C≡CH)] caused elimination of CO to create [OUCH], thus providing a new example of a well-defined substitution of an "yl" oxo ligand of UO in a unimolecular reaction.

Influence of Background HO on the Collision-Induced Dissociation Products Generated from [UONO].

Developing a comprehensive understanding of the reactivity of uranium-containing species remains an important goal in areas ranging from the development of nuclear fuel processing methods to studies of the migration and fate of the element in the environment. Electrospray ionization (ESI) is an effective way to generate gas-phase complexes containing uranium for subsequent studies of intrinsic structure and reactivity. Recent experiments by our group have demonstrated that the relatively low levels of residual HO in a 2-D, linear ion trap (LIT) make it possible to examine fragmentation pathways and reactions not observed in earlier studies conducted with 3-D ion traps (Van Stipdonk et al.

Collision-induced dissociation of [U O (ClO )] revisited: Production of [U O (Cl)] and subsequent hydrolysis to create [U O (OH)].

Rationale: In a previous study [Rapid Commun Mass Spectrom. 2004;18:3028-3034], collision-induced dissociation (CID) of [U O (ClO )] appeared to be influenced by the high levels of background H 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 H O was lower.