O2 AS TOOL TO STUDY METAL CATALYZED OXYGENATION REACTIONS

许多金属配合物能够与单线态氧干净地反应以产生新的金属-过氧配合物。这种方法提出了一种新的方法对金属-双氧配合物的制备，导致新的模型系统，模仿重要的酶和新的见解氧原子转移到各种基板的机制。过渡金属配合物与单线态氧的反应可以在非常低的温度下进行。因此，化学上非常不稳定的金属-双氧络合物，其存在以前仅限于推测的领域，可以合成，直接观察，并可以研究它们的反应性。同时，将研究单线态氧对金属的氧化加成的范围。到目前为止，还没有关于早期过渡金属的此类反应的报道。我们将尝试制备几个生物相关的过氧配合物来自早期过渡金属单线态氧。其他子项目将探讨金属配位硫醇盐氧化的机理特征。将检验金属氧化之后氧原子转移到硫原子是否是可行的反应途径。另一个子项目涉及合成一个内过氧化物配合铜络合物作为模型的铜酶槲皮素酶。单线态氧与双核配合物的不同反应也将被检查。总之，各种不同的子项目反映了不同的领域，其中利用单线态氧作为机械工具可能会导致重要的机械见解。

Many metal complexes are able to react cleanly with singlet oxygen to make new metal-peroxo complexes. This methodology suggests a new approach toward the preparation of metal-dioxygen complexes, leading to new model systems that mimic important enzymes and to new insights into the mechanism of oxygen atom transfer to a variety of substrates. Reactions of transition metal complexes with singlet oxygen can be carried out at very low temperatures. Thus, thermodynamically very unstable metal-dioxygen complexes whose existence has previously been limited to the realm of speculation can be synthesized, directly observed, and their reactivities can be studied. At the same time, the scope of oxidative addition of singlet oxygen to metals will be studied. Thus far, no such reactions have been reported for early transition metals. We will attempt to prepare several biologically relevant peroxo complexes derived from early transition metals with singlet oxygen. Other subprojects will probe the mechanistic features of the oxidation of metal-coordinated thiolates. It will be examined whether or not oxidation of the metal followed by oxygen atom transfer to the sulfur atom is a viable reaction pathway. Another subproject involves the synthesis of an endoperoxide coordinate to a copper complex as a model for the copper enzyme quercetinase. Different reactions of singlet oxygen with dinuclear complexes will also be examined. In summary, the various rather diverse subprojects reflect the diverse areas in which the utilization of singlet oxygen as a mechanistic tool may lead to important mechanistic insights.