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本文用CNDO/2方法计算了一组模式双氧络合物的电子结构,计算结果再现了催化剂中赤道配体的N原子数目及其参与的共轭程度同催化烃类氧化活性相关的实验结果。结果表明,处于赤道配体大环超共轭结构中、紧邻中心金属原子(或离子)的N原子,其特殊作用并非是其给体能力所致,介于C元素和O元素之间的适中的N元素电负性,维持了中心金属离子Fe(Ⅱ)低价态的稳定性,调整了Fe(Ⅱ)的d轨道能级,从而保证了支持Fe(Ⅱ)(d_(xz)和d_(yz))→O_2(π_A)的电子迁移,同时阻止O_2(π_B)→Fe(Ⅱ)(d_z~2)的电子迁移,这种由中心金属、双氧轴配体和赤道配体构成的整体效应,似乎是更为重要的。
In this paper, we calculated the electronic structure of a series of dioxygen complexes by the CNDO / 2 method. The calculation results reproduce the experimental results that the number of N atoms in the equator ligands and the degree of conjugation involved in the ligands are related to the catalytic activity of the hydrocarbon oxidation . The results show that the N atoms close to the central metal atom (or ion) in the superconjugated structure of the equatorial ligand macrocycle have a special function not due to their donor ability, which is moderate between the C and O elements (D) (xz) and d_ (subscript x)) of the Fe (Ⅱ) ions are controlled by the electronegativity of Fe (Ⅱ) (yz) → O_2 (π_A) electron transport while preventing the electron migration of O_2 (π_B) → Fe (Ⅱ) (d_z ~ 2), which is composed of central metal, dioxygen ligand and equatorial ligand The overall effect seems to be even more important.