排序方式: 共有79条查询结果,搜索用时 187 毫秒
31.
利用B3LYP方法,在6-311G基组下研究了气相中Fe~(2+)与H_2O_2作用生成OH自 由基的反应途径,探讨了铁离子对生成羟基自由基所起的作用。结果表明反应的途 径为:Fe~(2+)与H_2O_2首先形成中间体(FeO_2H_2)~(2+),然后能过O-O键的断 裂生成中间体(HOFeOH)~(2+),再断Fe-OH键生成羟基自由基,Fe~(2+)和H_2O_2 的电荷强烈相互作用以及Fe~(2+)的d轨道上的电子促进H_2O_2中的O-O键断裂,生 成羟基自由基。 相似文献
32.
The reaction path of the reaction HCN + OH→ CN + H2O was traced with Fukui's theory of intrinsic reaction coordinate by using ab initio MO method (at UMP4/6-31G** level) with gradient technique. On this basis, the dynamics properties along the reaction path was investigated by reaction path Hamiltonian theory. The rate constants of this reaction at different temperatures were calculated by conventional and variational transition state theory with tunneling correction. The theoretically calculated rate constants are in good agreement with experimental results, this shows that the title reaction is an one step, direct reaction. 相似文献
33.
草酰氯一价正离子构象及其碳—碳键反应活性的理论研究 总被引:1,自引:0,他引:1
用密度泛函方法BHandHLYP在6-311+G(d)和6-311+G(2df)水平上对草酰氯 的一价正离子[(ClCo)_2~+]作了构象分析,结果表明,(ClCo)_2~+具有平面 反式和交叉式两种稳定构象,交叉构象存在超共轭现象,此外,对草酰氯离子、中 性分子各解离通道初级反应的Gibbs自由能的计算,发现草酰氯离子C—C键解离通 道的反应活性大于中性分子,对该通道进一步做了反应机理研究,证实了热力学结 论,并且与实验相一致,对草酰氯离子的振动频率和键耦合常数的研究表明其碳— 碳键解离具有选键性。 相似文献
34.
The dynamical properties on reaction path (IRC) in internal coordinates have been obtained, which in. clude ω_K (frequencies orthogonal to IRC), L_K (vibrational modes), B_(KF) (coupling constants between the IRC and vibra tions orthogonal to it), B_(KL) (coupling constants between every two vibrations orthogonal to IRC). A set of theory of teac. tion path in molecular internal coordinates has been also constructed. The dynamical properties, including ω_K, B_(KF) B_(KL) of the reaction H~1O~2H~3 H~4→H~1O~2 H~3H~4 have been calculated, which explicitly explain the interaction, chang ing trend and contribution of each chemical bond (including bond angle) in the reaction. 相似文献
35.
采用UHF,CIS和CASSCF方法,在aug-cc-pvdz基组水平上对CH2=CCIFhv→·CH=CClF+H的光解反应通道及其后续反应作了研究.计算表明:分子吸收一个光子后,在第一电子激发态(S1)经过一个过渡态解离与Cl原子同侧的C-H键,这与用CIS方法计算垂直激发得到的π→σ*C-H跃迁及其对Frank-Condon点的计算中分子的单占轨道和键电荷密度变化所预测的结果是一致的.光解产物·CH=CCIF(基态)还可再发生反应,经过渡态解离C-Cl键或是C-F键. 相似文献
36.
37.
38.
39.
40.
四吡啶基卟啉质子化结构变化的理论研究 总被引:4,自引:0,他引:4
为考察m-吡啶基对质子化卟啉结构的影响,用半经验的AM1MO方法,并进行合理的对称性限制,计算了一类重要的卟啉衍生物---四吡啶基卟啉(TPyPH~2)及其质子化二酸(TP~yPH~4^2^+)的构型。通过结构分析,电荷布居分析和前沿轨道分析,讨论了质子化过程中的构型变化以及这种变化对分子堆积可能带来的影响。 相似文献