We recently reported a detailed investigation of the collision‐induced dissociation (CID) of [UO₂(NO₃)₃]⁻ and [UO₂(NO₃)₂(O₂)]⁻ in a linear ion trap mass spectrometer (J. Mass Spectrom. DOI:10.1002/jms.4705). Here, we describe the CID of [UO₂(NO₃)(O₂)]⁻ which is created directly by ESI, or indirectly by simple elimination of O₂ from [UO₂(NO₃)(O₂)₂]⁻. CID of [UO₂(NO₃)(O₂)]⁻ creates product ions as at m/z 332 and m/z 318. The former may be formed directly by elimination of O₂, while the latter required decomposition of a nitrate ligand and elimination of NO₂. DFT calculations identify a pathway by which both product ions can be generated, which involves initial isomerization of [UO₂(NO₃)(O₂)]⁻ to create [UO₂(O)(NO₂)(O₂)]⁻, from which elimination of NO₂ or O₂ will leave [UO₂(O)(O₂)]⁻ or [UO₂(O)(NO₂)]⁻, respectively. For the latter product ion, the composition assignment of [UO₂(O)(NO₂)]⁻ rather than [UO₂(NO₃)]⁻ is supported by ion‐molecule reaction behavior, and in particular, the fact that spontaneous addition of O₂, which is predicted to be the dominant reaction pathway for [UO₂(NO₃)]⁻ is not observed. Instead, the species reacts with H₂O, which is predicted to be the favored pathway for [UO₂(O)(NO₂)]⁻. This result in particular demonstrates the utility of ion‐molecule reactions to assist the determination of ion composition. As in our earlier study, we find that ions such as [UO₂(O)(NO₂)]⁻ and [UO₂(O)(O₂)]⁻ form H₂O adducts, and calculations suggest these species spontaneously rearrange to create dihydroxides.

中文翻译：

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碰撞诱导的[UO2（NO3）（O2）]-的解离和产物离子与H2O和O2的反应

我们最近报道了在线性离子阱质谱仪中对[UO ₂（NO ₃）₃ ] ^-和[UO ₂（NO ₃）₂（O ₂）] ^-的碰撞诱导解离（CID）进行的详细研究（J质谱（ DOI：10.1002 / jms.4705）。在这里，我们描述[UO ₂（NO ₃）（O ₂）] ^-的CID由ESI直接创建，或通过从[UO ₂（NO ₃）（O ₂）₂ ]中简单消除O ₂间接创建。^-。的CID [UO ₂（NO ₃）（O ₂）] ^-创建产物离子作为在M / Z 332和M / Z 318前者可以直接由消除的O-形成₂，而硝酸盐后者需要分解配体和NO _2的消除。DFT计算确定了可以生成两种产物离子的途径，该途径涉及[UO ₂（NO ₃）（O ₂）] ^-的初始异构化，从而生成[UO ₂（O）（NO ₂）（O ₂）] ^-，从中消除NO₂或O ₂将分别离开[UO ₂（O）（O ₂）] ^-或[UO ₂（O）（NO ₂）] ^-。对于后一种产物离子，[UO ₂（O）（NO ₂）] ^-而不是[UO ₂（NO ₃）] ^-的组成分配得到离子分子反应行为的支持，尤其是自发的事实O _2的添加，这预计是[UO ₂（NO ₃）] ^-的主要反应途径未观察到。相反，该物种与H ₂ O反应，H ₂ O被认为是[UO ₂（O）（NO ₂）] ^-的有利途径。该结果尤其证明了离子分子反应有助于确定离子组成的效用。与我们先前的研究一样，我们发现诸如[UO ₂（O）（NO ₂）] ^-和[UO ₂（O）（O ₂）] ^-的离子形成H ₂ O加合物，并且计算表明这些物种自发地重排产生二氢氧化物。