Ab initio classical trajectory study of the dissociation of neutral and positively charged methanimine (CH2NHn+ n = 0-2).
Ab initio classical trajectory study of the dissociation of neutral and positively charged methanimine (CH2NHn+ n = 0-2).
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中性和带正电甲胺 (CH2NHn n = 0-2) 解离的从头算经典轨迹研究。
DOI：
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发表时间：
2009
影响因子：
2.9
通讯作者：
H. Schlegel
中科院分区：
文献类型：
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作者：
Jia Zhou;H. Schlegel
在CBS-APNO理论水平上计算了甲亚胺中性、一价阳离子、双阳离子和三价离子解离的反应物、中间体、过渡态和产物的结构和能量。在B3 LYP/6- 311 G（d，p）水平上，采用从头算方法研究了中性、单价阳离子和双阳离子的离解反应.通过分别在中性、单电荷和双电荷物质的局部最小值上方分配200、150和120 kcal/mol的多余能量，构建了使用准经典正模采样的微正则系综。许多轨道直接解离产生H+、H原子或H2。然而，对于一小部分的情况下，氢的大量迁移发生在解离之前的分子内。中性和单价阳离子的优选解离产物是氢原子。在中性离子的20%的轨迹和单价离子的5%的轨迹中观察到H（2）的消除。二价阳离子和三价阳离子的解离产生H+而不是H原子。HCNH+在85-90%的一价阳离子和二价阳离子的解离轨迹中形成。
The structures and energetics of the reactants, intermediates, transition states, and products for the dissociation of methanimine neutral, monocation, dication, and trication were calculated at the CBS-APNO level of theory. The dissociations of the neutral, monocation, and dication were studied by ab initio direct classical trajectory calculations at the B3LYP/6-311G(d,p) level of theory. A microcanonical ensemble using quasiclassical normal mode sampling was constructed by distributing 200, 150, and 120 kcal/mol of excess energy above the local minima of the neutral, singly, and doubly charged species, respectively. Many of the trajectories dissociate directly to produce H+, H atom, or H2. However, for a fraction of the cases, substantial migration of the hydrogen occurs within the molecule before dissociation. The preferred dissociation product for the neutral and the monocation is hydrogen atom. Elimination of H(2) was seen in 20% of the trajectories for the neutral and in 5% of the trajectories for the monocation. Dissociations of the dication and trication produced H+ rather than H atom. HCNH+ was formed in 85-90% of the dissociating trajectories for the monocation and dication.