Small-to-Gigantic Transition Metal Clusters

在无机、生物无机和有机金属化学专业，这个项目的重点是过渡金属簇化合物的化学。该项目涉及新簇化合物的合成，其结构和键合的表征，以及其电化学和化学反应模式的研究。该研究的一个主要目标是基于分子轨道理论，在分子几何形状和各种金属簇的电子构型之间提供统一的相关性，其中许多金属簇在不破坏其原子框架的情况下获得和/或失去电子。过渡金属团簇化合物构成了一类重要的工业催化剂，一些非常大的团簇具有强烈的电流兴趣，因为它们表现出在小团簇或块状固体中看不到的异常磁性行为（“量子尺寸”效应）。该项目的主要重点是铂、镍和混合金属簇阴离子的合成、分离和表征。重点是设计合理的高核金属团簇合成路线和发展适当的分离技术，以便为结构和物理研究分离和结晶纯物种。另一个总体目标是通过适当的寡聚/缩合反应弥合离散和扩展固态团簇之间的差距。将合成含有S、Se、Te、N、P、As或Sb原子的主基配体的新型金属团簇。利用分子四磷光解法制备新的金属磷簇。将尝试使用无参数的Fenske-Hall模型为小金属团簇的晶体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.