Synthetic and Mechanistic Studies in Metal Cluster Chemistry

之前在一所主要的本科院校进行的这项研究项目的参与者包括一些目前在主要化学系攻读博士学位的学生。该项目有望为金属簇化合物的结构转变机制提供急需的信息。这类化合物是一类重要的催化剂，也是制备新型固体材料的重要前体。将研究由汞桥接的混合过渡金属团簇（包含M = Ru， Os和M'= VI族至VIII族，第一，第二或第三行过渡金属部分）光化学合成混合过渡金属团簇的方法。使用适当标记的配合物进行交叉实验，以评估导致M2M团簇形成的光诱导还原性消除汞的分子性，并研究起始团簇之间的热交换反应。研究这些汞桥接金属团簇的电子转移化学性质，以期促进汞的电化学还原消除。利用观察到的氘同位素动力学效应，研究了多核金属簇中配位体与金属核之间的氢转移机制（以及逆反应）。利用动力学氘同位素效应研究了多核过渡金属团簇中氢在金属原子之间的转移机理，以及这一过程与其他配体迁移的关系。

Previous participants in this research project at a primarily undergraduate institution have included a number of students currently enrolled in PhD programs in major chemistry departments. The project is expected to provide much-needed information about the mechanisms of structural transformations of metal cluster compounds. Such compounds are an important class of catalysts and are also important as precursors for the preparation of new solid materials. The photochemical synthesis of mixed transition metal clusters from mercury bridged mixed transition metal clusters (containing M = Ru, Os and M'= group VI thru group VIII, first, second or third row transition metal moiety) will be investigated. Crossover experiments using suitably labelled complexes will be conducted in order to evaluate the molecularity of the photo-induced reductive elimination of mercury which leads to formation of M2M'clusters and also to investigate the thermal exchange reactions between the starting clusters. The electron transfer chemistry of these mercury bridged metal clusters will be examined with a view towards promoting reductive elimination of mercury electro- chemically. The mechanisms of hydrogen transfer between coordinated ligands and the metal core (and the reverse reaction), in polynuclear metal clusters will be studied utilizing the observed kinetic deuterium isotope effects on these processes. The mechanisms of hydrogen transfer between metal atoms in polynuclear transition metal clusters and the relationship of this process to other ligand migrations will be studied utilizing the kinetic deuterium isotope effects previously documented for hydrogen migrations in several hydrido-metal clusters.