Elucidation of the relationship between the structure and the reactivity of transition metal dioxygen complexes

为了了解中心金属与氧配合物的结构和反应活性之间的关系，我们系统地合成了含氢三吡唑基硼的氧配合物。因此，我们制备了各种不同的氧配合物，并用光谱学和结晶学方法对其进行了表征，在此基础上提出了一种有效的过氧物活化方法。发展了一种新的氧络合物的制备方法，即羟基金属络合物与过氧化氢的脱水缩合反应，并制备了多种氧加合物。制备了钴和镍的双金属双μ-氧物种，并用X-射线单晶衍射法对其进行了表征。这些物种能够氧化配体的碳氢基部分，结合相关工作，我们的结果现在被认为是这种物种存在和高活性的证据，它被认为参与了甲烷单加氧酶的活性部位。氧加合物的结构取决于中心金属的d轨道能级和中心金属与过氧化氢配体之间的几何排列。过氧基中间体的O-O均解导致金属氧基自由基的产生是一种很有前途的将不活跃的过氧基物种转化为活性氧化剂的方法，并且发现O-O均解依赖于中心金属d-轨道的能级4。对含有活性氧物种的第二排金属络合物进行了充分的表征，并从分子水平上理解了氧的活化过程

For the understanding of the relationship between the central metal and the structure and reactivity of the dioxygen complexes a systematic synthetic study of dioxygen complexes bearing the hydrotrispyraxolylborate has been carried out. As a result, a variety of dioxygen complexes have been prepared and characterized by spectroscopic and crystallographic methods and, on the basis of the results obtained, an effective activation method for peroxo species is proposed1. The new preparative method for dioxygen complexes, i. e. dehydrative condensation between hydroxometal complex and hydrogen peroxide, has been developed and a variety of dioxygen adducts have been prepared2. The dimetalbis-μ-oxo species of cobalt and nickel were prepared and fully characterized by X-ray crystallography. The species are able to oxygenate the hydrocarbyl moieties of the ligand and combined with the related works our result is now regarded as evidence for thee occurrence and high activity of such a species, which is proposed to be involved in the active site of methane monooxygenase3. The structure of the oxygen adducts are dependent on the d-orbital energy level of the central metal and the geometrical arrangement between the central metal and the peroxide ligand4. O-O homolysis of a peroxo intermediate leading to metaloxy radical resulting is a promising method for conversion of the inactive peroxo species into an active oxygenating reagent and the O-O homolysis is found to be dependent on the energy level of d-orbitals of the central metals4. Second row metal compelxes containing an active oxygen species such as M-OOH species, which have been believed to be very unstable, are fully characterized and oxygen-activation processes are understood at a molecular level