Small-to-Gigantic Transition Metal Clusters

无机化学、生物无机化学和金属有机化学项目的重点是过渡金属簇合物的化学。该项目包括合成新的簇合物，表征它们的结构和成键，以及研究它们的电化学反应模式。这项研究的一个主要目标是基于分子轨道理论，在各种金属团簇的分子几何和电子构型之间提供统一的关联，其中许多金属团簇在不破坏其原子结构的情况下获得和/或失去电子。过渡金属簇合物是一类重要的工业催化剂，一些非常大的簇合物表现出在小团簇或块状固体中看不到的反常磁性行为(量子尺寸效应)，因此引起了人们的强烈兴趣。该项目的主旨将是铂、镍和混合金属团簇阴离子的合成、分离和表征，重点是设计通往高核度金属团簇的合理合成路线，并开发适当的分离技术，以便能够分离和结晶纯物种，用于结构和物理研究。另一个总体目标是通过适当的齐聚/缩合反应来弥合离散和扩展固态团簇之间的差距。合成了以S、Se、Te、N、P、As或Sb为主基配体的新型金属簇合物。新的金属磷团簇将通过分子四磷光解来制备。尝试使用无参数Fenske-Hall模型，为小金属团簇的结晶学和光谱分析结果提供定量的电子基础。

The focus of this project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is the the chemistry of transition metal cluster compounds. The project involves the synthesis of new cluster compounds, characterization of their structures and bonding, and studies of their electrochemical and chemical reactivity patterns. A major objective of the research is to provide a unified correlation, based on molecular orbital theory, between molecular geometries and electronic configurations for various kinds of metal clusters, many of which gain and/or lose electrons without rupture of their atomic frameworks. Transition metal cluster compounds comprise an important class of industrial catalysts, and some very large clusters are of intense current interest because they display anomalous magnetic behavior ("quantum size" effects) not seen in small clusters or bulk solids. The main thrust of the project will be the synthesis, isolation and characterization of platinum, nickel and mixed-metal cluster anions, with emphasis on the design of rational synthetic routes to high-nuclearity metal clusters and the development of appropriate separation techniques to enable the isolation and crystallization of pure species for structural and physical studies. Another overall goal is to bridge the gap between discrete and extended solid-state clusters via appropriate oligomerization/condensation reactions. New metal clusters will be synthesized which contain main-group ligands with S, Se, Te, N, P, As or Sb atoms. New metal phosphorus clusters will be prepared by the photolysis of molecular tetraphosphorus. An attempt will be made to use the parameter-free Fenske-Hall model to provide a quantitative electronic basis for the results of crystallographic and spectrocopic analyses of small metal clusters.