†Chemical Sciences Division, ‡Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
J Am Chem Soc. 2015 May 13;137(18):5911-5. doi: 10.1021/jacs.5b02420. Epub 2015 May 1.
Activation of the oxo bond of uranyl, UO2(2+), was achieved by collision induced dissociation (CID) of UO2(N3)Cl2(-) in a quadrupole ion trap mass spectrometer. The gas phase complex UO2(N3)Cl2(-) was produced by electrospray ionization of solutions of UO2Cl2 and NaN3. CID of UO2(N3)Cl2(-) resulted in the loss of N2 to form UO(NO)Cl2(-), in which the "inert" uranyl oxo bond has been activated. Formation of UO2Cl2(-) via N3 loss was also observed. Density functional theory computations predict that the UO(NO)Cl2(-) complex has nonplanar Cs symmetry and a singlet ground state. Analysis of the bonding of the UO(NO)Cl2(-) complex shows that the side-on bonded NO moiety can be considered as NO(3-), suggesting a formal oxidation state of U(VI). Activation of the uranyl oxo bond in UO2(N3)Cl2(-) to form UO(NO)Cl2(-) and N2 was computed to be endothermic by 169 kJ/mol, which is energetically more favorable than formation of NUOCl2(-) and UO2Cl2(-). The observation of UO2Cl2(-) during CID is most likely due to the absence of an energy barrier for neutral ligand loss.
通过在四极离子阱质谱仪中对 UO2(N3)Cl2(-)进行碰撞诱导解离 (CID)，实现了铀酰 UO2(2+) 的氧键活化。气相配合物 UO2(N3)Cl2(-)是通过 UO2Cl2 和 NaN3 的溶液电喷雾电离产生的。UO2(N3)Cl2(-)的 CID 导致 N2 的损失，形成 UO(NO)Cl2(-)，其中“惰性”铀酰氧键已被活化。也观察到通过 N3 损失形成 UO2Cl2(-)。密度泛函理论计算预测 UO(NO)Cl2(-)配合物具有非平面 Cs 对称性和单重基态。对 UO(NO)Cl2(-)配合物的键合分析表明，侧接的 NO 部分可以被认为是 NO3-，表明 U 具有 VI 价。UO2(N3)Cl2(-)中的铀酰氧键的活化形成 UO(NO)Cl2(-)和 N2 的过程被计算为吸热 169 kJ/mol，这在能量上比形成 NUOCl2(-)和 UO2Cl2(-)更有利。CID 期间观察到 UO2Cl2(-)最可能是由于中性配体损失没有能垒。
