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用半经验的AM1,ab initio(HF/3-21C,HF/6-31G~(?)),及密度泛函[B3LYP/6-31G~(?),B3LYP/6-311G(d,p)]方法对1,4-苯醌及其阴离子的结构与性质进行了研究.在此基础上用AM1及BLYP/6-31G(d,p)方法对泛醌Q_0,用AM1方法对泛醌Q_1;,泛醌Q_2及其阴离子的结构与性质进行了研究.研究结果表明,由于取代基的影响,泛醌的环平面发生了扭曲,环上原子不再位于同一平面上结构的变化导致了电子分布发生了变化,并由此导致了偶极矩随6位上取代基的增大而增大.随着6位支链的增长,泛醌的电离势逐渐减小而电子亲和势逐渐增大,泛醌传递电子的能力增强.在上述研究的基础上,对1,4-苯醌及泛醌的自交换电子转移反应过程进行了研究,计算了反应的内重组能,溶剂重组能及电子转移速率常数.结果表明内重组能的大小与取代基的长短无直接关系,而与得电子前后醌的结构变化程度密切相关.除高频振动的变化外,低频振动的变化对内重组能也有显著的贡献.计算所得1,4-苯醌自交换电子转移反应速率常数与实验值相符得很好.
Using semi-empirical AM1, ab initio (HF / 3-21C, HF / 6-31G?), And density functional theory [B3LYP / 6-31G ?, B3LYP / 6-311G )] Method was used to study the structure and properties of 1,4-benzoquinone and its anion.On the basis of ubiquinone Q_0 with AM1 and BLYP / 6-31G (d, p) methods, ubiquinone The structures and properties of ubiquinone Q_2 and its anions were studied.The results show that the ring plane of ubiquinone is distorted due to the influence of substituents and the structure of atoms on the ring is no longer in the same plane The electron distribution changes, and as a result, the dipole moment increases with increasing substituents at position 6. The ionization potential of ubiquinone gradually decreases and the electron affinity gradually increases as the 6-position branch grows On the basis of the above studies, the self-exchange electron transfer reaction process of 1,4-benzoquinone and ubiquinone was studied, and the internal reorganization energy of the reaction, the solvent recombination energy And electron transfer rate constants.The results show that the size of the internal recombination energy is not directly related to the length of the substituents but closely related to the structural changes of the electronic quinone before and after addition.In addition to the change of high frequency vibration, Frequency vibration can change the internal reorganization has a significant contribution calculated from the resulting 1,4-benzoquinone exchange electron transfer rate constant of the reaction is consistent with the experimental well.