Highly Symmetrical Metal Alkoxides and Amines

该项目在无机，生物无机和有机 化学课程关注的是如何将 与金属结合的某些基团的空间位阻 改变了金属在与 其他各组这项工作的目标是利用空间位阻 以微调的化学和光谱性质的 金属，并且例如由此提供更好的控制和 金属基催化剂的选择性。 金属醇盐和酰胺将利用配体合成 框架，其约束供体原子的位置， 它们与金属结合。例如，配体可以具有 三脚架的形状，供体原子在三脚架的末端， 腿，或者它可以是四齿的供体原子 位置就好像它们位于四条腿的末端一样 位子.在金属原子周围将存在高的局部对称性 在这些络合物中，导致配体与金属的还原 与无环配体的络合物相比，π键合。的 预计金属上的负电荷会减少 为了增加配体的金属-配体键合， 受约束配体的供体原子，并且还增加M-M 双核LMML物种中的多重键合，其中L是 约束多齿配体。这些影响的程度 将通过光谱学（异相NMR和IR）进行研究， 结构（通过X射线晶体学）和化学（通过 研究配合物进行配位的倾向 球膨胀，小分子插入，烷烃复分解 和簇形成反应）。

This project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is concerned with the way in which imposing steric constraint on some of the groups bound to a metal changes the properties of the metal in its interactions with other groups. The goal of the work is to use steric constraints to fine-tune the chemical and spectroscopic properties of the metal, and, for example, thereby to provide better control and selectivity in metal-based catalysis. Metal alkoxides and amides will be synthesized utilizing ligand frameworks which constrain the positions of the donor atoms as they bind to the metal. For example, the ligand may have the shape of a tripod, with the donor atoms at the ends of the legs, or it may be quadridentate with the donor atoms positioned as though they were at the ends of the four legs of a table. High local symmetry will exist around the metal atom in these complexes, resulting in a reduction of ligand-to-metal pi bonding compared to complexes of acyclic ligands. The resultant reduction in negative charge on the metal is expected to increase the metal-ligand bonding of ligands other than the donor atoms of the constrained ligand, and also to augment M-M multiple bonding in the dinuclear LMML species, where L is the constrained multidentate ligand. The magnitude of these effects will be studied spectroscopically (heteronuclear NMR and IR), structurally (via X-ray crystallography) and chemically (by studying the tendencies of complexes to undergo coordination sphere expansion, small molecule insertions, alkane metatheses and cluster-forming reactions).