Fundamental Aspects of the Dinuclear Chemistry of Molybdenumand Tungsten

本文将从合成和结构两个方面探讨形式电荷为4~10的钼、钨双核阳离子过渡金属络合物的配位化学。将启动配体取代反应的动力学和机理研究以及双核金属中心的有机金属化学。由于金属-金属键的影响，这些结果可能与深入研究的单核配合物有很大不同。我们将研究以双核金属多键为基块形成的有序组装，如液晶和聚合物，重点研究这些大分子体系的可控磁性、光学和电学性质。双核前体的第一电离电势随金属和取代基的不同而变化2伏；这些特征应该允许大量具有可调电子性质的大分子体系。在化学部无机、生物无机和有机金属项目中，印第安纳大学的Malcolm H.Chisholm博士将继续他对钼和钨双核配合物丰富化学的研究。这些分子显示出相当大的作为均相催化剂的前景。此外，它们可以在适当的条件下组装成液晶和聚合物，作为新材料可能具有有用的性能。

The coordination chemistry of dinuclear cationic transition metal complexes of molybdenum and tungsten with formal charges of four to ten will be explored through synthesis and structural methods. Kinetic and mechanistic studies of ligand substitution reactions and the organometallic chemistry of dinuclear metal centers will be initiated. These results may differ substantially from the thoroughly investigated mononuclear complexes due to the influence of the metal-metal bond. Ordered assemblies such as liquid crystals and polymers formed by use of dinuclear metal multiple bonds as building blocks will be investigated, with emphasis on the controllable magnetic, optical, and electronic properties of these macromolecular systems. The dinuclear precursors have first ionization potentials that vary by two volts depending on metal and the substituents; these features should allow a large array of macromolecular systems with tunable electronic properties. %%% In this project in the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division, Dr. Malcolm H. Chisholm of Indiana University will continue his studies of the rich chemistry of dinuclear complexes of molybdenum and tungsten. These molecules show considerable promise as homogeneous catalysts. In addition, they can be assembled under proper conditions to form liquid crystals and polymers that may have useful properties as new materials.