Ligand control of the metal coordination sphere by design in coordination and organometallic chemistry

这项建议中概述的研究旨在控制化合物中金属离子的物理和化学性质。稀土金属化合物是这项工作的主要焦点，因为它们与其他金属相比具有重要的优势，包括更高的反应活性、不同的选择性、适中的成本以及良好的电子和核性能。尽管有这些因素，稀土化学的发展一直很缓慢，部分原因是这些金属需要特殊的配位环境才能形成活性化合物。例如，在催化中，必须在形成稳定的、可分离的化合物和具有足够反应活性的金属中心之间取得微妙的平衡，以便进行有用的化学转化。因此，为形成这一建议基础的稀土元素开发新的配位环境，对于实际执行这些金属至关重要。这里介绍的新配位系统旨在实现两个不同的目的：(I)提高水和有机溶剂中C-C键形成反应的催化活性和选择性；(Ii)水和空气稳定的络合物，在医学成像(磁共振、伽马成像、荧光成像)或治疗(作为靶向抗癌药物的放射性-稀土络合物)中具有药物应用。第二个主要项目涉及利用金属配位来改善有机分子在不同状态之间的光化学转换，这可能在光学数据存储中应用。在所有情况下，成功实现所需的反应性或性能取决于对金属配位环境的仔细设计。

The research outlined in this proposal is aimed at controlling the physical and chemical properties of metal ions in compounds. Compounds of the lanthanide metals are the main focus of this work because they offer important advantages over other metals including higher reactivity, different selectivity, moderate cost and desirable electronic and nuclear properties. In spite of these factors, lanthanide chemistry has been slow to develop, partly because these metals require special coordination environments to form reactive compounds. In catalysis, for example, a fine balance must be achieved between formation of stable, isolable compounds and metal centres with sufficient reactivity to carry out useful chemical transformations. The development of new coordination environments for the lanthanides that forms the basis of this proposal is therefore critical to the practical implementation of these metals. The new coordination systems described here are designed to achieve two different purposes: (i) improved catalytic activity and selectivity in C-C bond forming reactions in water and organic solvents, and (ii) water and air stable complexes with pharmaceutical applications in medical imaging (magnetic resonance, gamma imaging, fluorescence imaging) or therapy (radio-lanthanide complexes as targeted anti-cancer drugs). A second major project, involves using metal coordination to improve the photochemical switching of organic molecules between different states with potential application in optical data storage. In all cases, success in achieving the desired reactivity or properties rests with careful design of the metal coordination environment.