Abergel Rebecca J, de Jong Wibe A, Deblonde Gauthier J-P, Dau Phuong D, Captain Ilya, Eaton Teresa M, Jian Jiwen, van Stipdonk Michael J, Martens Jonathan, Berden Giel, Oomens Jos, Gibson John K
Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Computational Research Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Inorg Chem. 2017 Nov 6;56(21):12930-12937. doi: 10.1021/acs.inorgchem.7b01720. Epub 2017 Oct 11.
Recent efforts to activate the strong uranium-oxygen bonds in the dioxo uranyl cation have been limited to single oxo-group activation through either uranyl reduction and functionalization in solution, or by collision induced dissociation (CID) in the gas-phase, using mass spectrometry (MS). Here, we report and investigate the surprising double activation of uranyl by an organic ligand, 3,4,3-LI(CAM), leading to the formation of a formal U chelate in the gas-phase. The cleavage of both uranyl oxo bonds was experimentally evidenced by CID, using deuterium and O isotopic substitutions, and by infrared multiple photon dissociation (IRMPD) spectroscopy. Density functional theory (DFT) computations predict that the overall reaction requires only 132 kJ/mol, with the first oxygen activation entailing about 107 kJ/mol. Combined with analysis of similar, but unreactive ligands, these results shed light on the chelation-driven mechanism of uranyl oxo bond cleavage, demonstrating its dependence on the presence of ligand hydroxyl protons available for direct interactions with the uranyl oxygens.
近期激活双氧铀酰阳离子中强铀-氧键的努力，仅限于通过溶液中的铀酰还原和官能化，或利用质谱法（MS）在气相中通过碰撞诱导解离（CID）来实现单氧基团的激活。在此，我们报告并研究了有机配体3,4,3-LI(CAM)对铀酰的惊人双重激活作用，该作用导致在气相中形成一种形式上的U螯合物。通过使用氘和O同位素取代的CID以及红外多光子解离（IRMPD）光谱，实验证明了两个铀酰氧键的断裂。密度泛函理论（DFT）计算预测，整个反应仅需132 kJ/mol，首次氧激活约需107 kJ/mol。结合对类似但无反应性配体的分析，这些结果揭示了铀酰氧键断裂的螯合驱动机制，证明了其对可与铀酰氧直接相互作用的配体羟基质子存在的依赖性。
