Modulating the reactivity of uranyl by manipulating the O=U=O bond angle in uranyl ansa-type cyclopentadienyl complexes

通过操纵双氧铀酰型环戊二烯基配合物中的 O=U=O 键角来调节双铀酰的反应性

• 批准号: 2657739
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2657739
• 关键词: Modulating; reactivity; uranyl; manipulating; O=U=O

The actinide elements display some of the most diverse chemistry encountered anywhere in the Periodic Table, with the key nuclear fuel cycle elements (U, Np and Pu) being the most complex. In aerobic conditions, the +VI (U) and +V (Np) oxidation states dominates and these formdioxo actinyl ions AnO22+ with linear O=An=O bonds. While these have well known andextensive coordination chemistry, there are some remarkable features that have been recentlydiscovered challenging the traditional view and understanding of the thermodynamic stability andkinetic inertness of the actinyl unit (here, uranyl). The redox chemistry of the actinides is also complex;uranyl(V) ions are susceptible to disproportionation and these reactions involve activation of the uranyl bond and oxygen atom transfer reactions, yet the mechanisms for such processes remain unclear. This project aims to probe the bonding in the uranyl cation by employing strongly sigma donating and geometrically constrained ansa-type cyclopentadienyl ligands to influence the reactivity of the uranyl unit. This will alter its electronic structure and reactivity, where we will probe its redox chemistry by luminescence spectroscopy in particular, including oxygen atom transfer reactions, to understand redox processes that occur in nuclear recycle and disposal scenarios.Specific aims are to:- Synthesise a new family of uranyl(VI) complexes coordinated to ansa-Cp type ligands from high valent oxo precursors.- Probe of the electronic structure by optical/ vibrational spectroscopies and DFT calculations.- Investigate the reactivity of the ansa-Cp uranyl complexes for oxygen atom transfer reactions with O atom transfer reagents.- Investigate the photophysics of the ansa-Cp uranyl complexes using UV and visible light using transient absorption and ultrafast emission spectroscopies.- Investigate synthetic routes to uranyl(V) derivatives.

锕系元素具有元素周期表中最多样化的化学性质，其中关键的核燃料循环元素（U、Np 和 Pu）最为复杂。在有氧条件下，+VI (U) 和 +V (Np) 氧化态占主导地位，这些形成具有线性 O=An=O 键的二氧锕基离子 AnO22+。虽然它们具有众所周知且广泛的配位化学，但最近发现的一些显着特征挑战了对锕基单元（此处为铀酰）的热力学稳定性和动力学惰性的传统观点和理解。锕系元素的氧化还原化学也很复杂；铀酰（V）离子容易发​​生歧化，这些反应涉及铀酰键的活化和氧原子转移反应，但此类过程的机制仍不清楚。该项目旨在通过使用强西格玛供体和几何约束的 ansa 型环戊二烯基配体来探测铀酰阳离子中的键合，以影响铀酰单元的反应性。这将改变其电子结构和反应性，我们将通过发光光谱特别是包括氧原子转移反应来探测其氧化还原化学，以了解核回收和处置场景中发生的氧化还原过程。具体目标是：- 合成一种新的铀酰 (VI) 配合物家族与高价含氧前体的 ansa-Cp 型配体配位。- 通过光学/振动光谱和 DFT 计算探测电子结构。- 研究ansa-Cp 铀酰配合物与 O 原子转移试剂进行氧原子转移反应的反应性。- 使用紫外和可见光，使用瞬态吸收和超快发射光谱研究 ansa-Cp 铀酰配合物的光物理学。- 研究铀酰的合成路线（五）衍生品。