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

本提案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。镧系金属的化合物是这项工作的主要焦点，因为它们比其他金属具有重要的优势，包括更高的反应性，不同的选择性，适中的成本和理想的电子和核性质。尽管有这些因素，镧系化学发展缓慢，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，在催化作用中，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良好的平衡，以进行有用的化学转化。因此，为构成本建议基础的镧系元素开发新的配位环境对这些金属的实际实施至关重要。本文描述的新配位系统旨在实现两个不同的目的：(i)在水和有机溶剂中提高C-C键形成反应的催化活性和选择性，以及（ii）在医学成像（磁共振、伽马成像、荧光成像）或治疗（放射性镧系化合物作为靶向抗癌药物）中具有水和空气稳定性的配合物的制药应用。第二个主要项目涉及使用金属配位来改善有机分子在不同状态之间的光化学开关，并在光学数据存储中有潜在的应用。在所有情况下，成功地获得所需的反应性或性质取决于金属配位环境的精心设计。

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.