反式双氧锰(V)咔咯配合物的稳定性

采用密度泛函理论(DFT)的B3LYP方法对反式双氧锰(V)咔咯配合物阴离子的稳定性及其质子化物种进行了理论计算. 结果表明: 反式双氧锰(V)咔咯配合物阴离子构型稳定, 其反式双氧锰键O=Mn=O由锰原子的d轨道与两个氧原子的p轨道分别构成一个σ轨道和两个π轨道; 随着外围取代基吸电性增强, O=Mn=O键长缩短, 拉曼伸缩振动频率增大; 其质子化过程中得到两个质子的轴向氧原子与锰原子的距离超出正常化学键的范围, 从而形成水分子并脱离原来分子, 导致质子化行为是不可逆过程, 而形成单氧的咔咯锰(V)-氧配合物.

Stability of trans-Dioxo Manganese(V) Corrole Complex

The stability of anionic trans-dioxo manganese(V) corrole complex and the protonated species structure were investigated using density functional theory (DFT) with B3LYP method. The calculation results show that trans-dioxo manganese(V) corrole complex has one σ and two π orbitals in its O=Mn=O bonds, which are composed of the d orbital of the manganese atom and p orbitals of the two oxygen atoms. Enhancement of the electron-withdrawing ability of substituents results in a decrease in the O=Mn=O bond lengths, and shifts the O=Mn=O Raman stretching vibration to a higher wavenumber. On protonation, one of the axial oxygen atoms gains two protons and is transformed into a water molecule. The manganese atom then cannot hold water tightly to form effective coordination bonds with water. This results in irreversible protonation of the trans-dioxo manganese(V) corrole complex, which leads to formation of an oxomanganese (V) corrole complex.