Anbalagan Victor, Chien Winnie, Gresham Garold L, Groenewold Gary S, Van Stipdonk Michael J
Department of Chemistry, Wichita State University, Wichita, KS 67260-0051, USA.
Rapid Commun Mass Spectrom. 2004;18(24):3028-34. doi: 10.1002/rcm.1726.
Electrospray ionization was used to generate mono-positive gas-phase complexes of the general formula [UO2A(S)n]+ where A = OH, Cl, Br, I or ClO4, S = H2O, CH3OH or CH3CH2OH, and n = 1-3. The multiple-stage dissociation pathways of the complexes were then studied using ion-trap mass spectrometry. For H2O-coordinated cations, the dissociation reactions observed included the elimination of H2O ligands and the loss of HA (where A = Cl, Br or I). Only for the Br and ClO4 versions did collision-induced dissociation (CID) of the hydrated species generate the bare, uranyl-anion complexes. CID of the chloride and iodide versions led instead to the production of uranyl hydroxide and hydrated UO2+. Replacement of H2O ligands by alcohol increased the tendency to eliminate HA, consistent with the higher intrinsic acidity of the alcohols compared to water and potentially stronger UO2-O interactions within the alkoxide complexes compared to the hydroxide version.
采用电喷雾电离法生成通式为[UO₂A(S)ₙ]⁺的单正电荷气相配合物，其中A = OH、Cl、Br、I或ClO₄，S = H₂O、CH₃OH或CH₃CH₂OH，且n = 1 - 3。然后使用离子阱质谱研究配合物的多级解离途径。对于与H₂O配位的阳离子，观察到的解离反应包括H₂O配体的消除和HA（其中A = Cl、Br或I）的损失。仅对于Br和ClO₄版本，水合物种的碰撞诱导解离（CID）产生了裸露的铀酰 - 阴离子配合物。氯化物和碘化物版本的CID反而导致生成氢氧化铀酰和水合UO₂⁺。用醇取代H₂O配体增加了消除HA的倾向，这与醇相对于水具有更高的固有酸度以及与氢氧化物版本相比，醇盐配合物中潜在更强的UO₂ - O相互作用一致。
