Thermochemical and Reactivity Studies of Basic Transition Metal Complexes

爱荷华州立大学安吉利西分校9414242号爱荷华州立大学化学系Robert J.Angelici博士由化学部无机化学、生物无机化学和有机金属化学项目资助，主要从事碱性过渡金属络合物的热化学和反应性研究。这个项目的一个主要目标是定量确定决定金属氢化物络合物中金属中心的碱度或“电子丰度”的因素。为了确定金属及其配体对络合物碱性的贡献，将测量一系列铬、钨、Re、铁、Ru、Os、钴、Rh和Ir的单核络合物的量热测定的质子化热焓。这些热能将与电化学氧化势结合，得到键离解能。研究将扩展到多核复合体。许多过渡金属氢化物是各种工业和实验室过程的催化剂。这些催化剂的活性与氢从金属转移到反应物物种的容易程度有关。然而，关于决定金属和氢原子之间相互作用强度的因素，现有的定量信息很少。在这个项目中，将确定一系列金属络合物的金属-氢键强度。这些研究将为理解过渡金属络合物和催化剂的广泛反应性提供基础。

9414242 Angelici Iowa State Univ. Dr. Robert J. Angelici, Chemistry Department, Iowa State University, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division for research into thermochemical and reactivity studies of basic transition metal complexes. A major goal of this project is to quantitatively determine the factors which determine the basicity, or "electron richness", of metal centers in metal-hydride complexes. The calorimetrically determined enthalpies of protonation will be measured for a series of mononuclear complexes of chromium, tungsten, rhenium, iron, ruthenium, osmium, cobalt rhodium, and iridium in order to establish contributions of the metal and its ligands to the basicities of the complexes. These enthalpies will be combined with electrochemical oxidation potentials to give bond dissociation energies. The studies will be extended to polynuclear complexes. Many transition metal hydride complexes are catalysts for a variety of industrial and laboratory processes. The activity of these catalysts is related to the ease with which the hydrogen can move from metal to a reactant species. However, there is very little quantitative information available on the factors which determine the strength of the interaction between a metal and a hydrogen atom. In this project the metal-hydrogen bond strengths will be determined for a range of metal complexes. These studies will provide a basis for understanding a broad range of reactivities of transition metal complexes and catalysts.