Making, Stabilising and Understanding Unusual Intermediate Oxidation States in the Early Actinides

能源的使用，特别是以电力的形式，是现代生活的基本要求，也是我们大多数人甚至无法想象没有的生活。从交通和旅行到计算机和电视，全球对能源的需求正在增加。然而，最近技术进步的缺点是，在能源生产过程中排放温室气体，特别是二氧化碳。公众对气候变化及其未来对世界的影响的认识不断提高，最近已经将重点从化石燃料的使用转移到替代能源，现在已经制定了减少碳足迹的立法。在各种备选方案中，核能在短期内仍然是最可行的，因为该技术已经到位，可以进行熟练的能源生产。核能发电目前供应全球能源需求的17%左右（英国为18.4%）。并且由于与废物储存和生产相关的高水平放射性废物已经产生了遗留的环境问题。该提案集中于核燃料工业中使用的放射性锕系元素离子（铀、钚和镎）的化学性质，识别和“清理"环境中有毒废物的方法，以及消除未来储存高放射性废物的必要性的方法。由于目前反应堆中使用的锕系元素是在与自然环境不同的条件下产生的，这些金属在反应堆外的化学性质完全不同，它们通常在进一步改变或反应之前以不寻常的氧化态存在一段时间。为了减少这些放射性有毒废物对环境的有害影响，我们必须全面了解它们的化学性质。这只能通过在受控的实验室条件下使用专门设计的化学方法研究这些金属在其反应性不稳定氧化态下的化学性质来实现。通过这样做，我们可以确定稳定这些氧化态的方法，以及从污染场地选择性地去除它们的方法，以便它们最终可以回收并用于进一步的能源生产。本项目将通过在厌氧条件下合成一系列由不同有机基团稳定的络合物，初步研究+V氧化态铀的化学性质，并研究其周围的化学基团抑制或增强反应性的方式。这种化学方法将用于稳定放射性更强的元素钚和镎。该项目的核心是开发这些元素的不稳定（和稳定）氧化态的光谱指纹（使用时间分辨发光光谱），以便开发一种非侵入性方法来识别环境中可能存在于使用当前辐射和化学方法太快的时间尺度上的此类物种。

Energy use, especially in the form of electricity is an essential requirement for modern life, and one that most of us could not even contemplate living without. From transport and travel to computers and televisions, the global demand for energy is on the increase. The drawback of recent technological advances however, is that greenhouse gases, in particular CO2 are emitted during the production of energy. Growing public awareness of climate change and its future impacts on the world as we know it have recently shifted the focus from fossil fuel usage to alternative energy sources, and legislation is now in place for reducing the carbon footprint. Among the alternative options, nuclear energy remains the most viable in the short term since the technology is already in place for proficient energy production. Nuclear electricity generation currently supplies around 17 % of the worldwide energy demand (18.4 % in the U.K.) and has already created a legacy of environmental problems due to high level radioactive wastes associated with waste storage and production. This proposal concentrates on the chemistry of the radioactive actinide ions (uranium, plutonium and neptunium) used in the nuclear fuel industry, ways to identify and 'clean up' toxic wastes from the environment and methods to eliminate the need for storing high level wastes in the future. Since the actinides used in current reactors are generated under conditions that are dissimilar to the natural environment, the chemistry of these metals outside of the reactor is completely different and they often exist in unusual oxidation states for a certain period of time before being further altered or reacting. In order to reduce the detrimental impact these radiotoxic wastes have on the environment, it is imperative that we understand their chemistry in full. This can only be achieved by studying the chemistry of these metals in their reactive unstable oxidation states in controlled laboratory conditions using specially designed chemistry. By doing this, we can identify methods of stabilizing these oxidation states and ways for selectively removing them from contaminated sites so that they can ultimately be recycled and used for further energy production. This project will initially examine the chemistry of uranium in the +V oxidation state by synthesizing a range of complexes stabilized by different organic groups under anaerobic conditions, and study the way the chemical groups around them inhibit or enhance reactivity. This chemistry will then be applied to the stabilization of the more radiotoxic elements plutonium and neptunium. At the core of the project is the development of a spectroscopic fingerprint (using time resolved luminescence spectroscopy) of unstable (and stable) oxidation states of these elements in order to develop a non-invasive method of identifying such species in the environment that may exist on a timescale that is too fast using current radiometric and chemical methods.