Breakdown of the Born-Oppenheimer approximation in the F+o-D2→DF+D reaction
Breakdown of the Born-Oppenheimer approximation in the F+o-D2→DF+D reaction
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DOI：
10.1126/science.1144984
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发表时间：
2007-08-24
期刊：
影响因子：
56.9
通讯作者：
Alexander, Millard H.
中科院分区：
文献类型：
--
作者：
Che, Li;Ren, Zefeng;Alexander, Millard H.
F 与 H-2 及其同位素异构体的反应是放热三原子抽象反应的范例。在交叉光束散射实验中，我们确定了地面 F(P-2(3/2)) 和激发 F*(P-2(1/2)) 自旋轨道态与 D-2 反应的相对积分和微分截面，碰撞能量为 0.25 至 1.2 千卡/摩尔。在最低碰撞能量下，尽管 F* 的反应在玻恩-奥本海默 (BO) 近似范围内被禁止，但 F* 的反应性大约是 F 的 1.6 倍。随着碰撞能量的增加，BO 允许的反应迅速占主导地位。我们发现多态、量子反应散射计算与测量的 F*/F 反应性比和微分横截面的能量依赖性之间具有极好的一致性。该协议证实了对控制抽象反应中电子非绝热性的因素的基本理解。
The reaction of F with H-2 and its isotopomers is the paradigm for an exothermic triatomic abstraction reaction. In a crossed-beam scattering experiment, we determined relative integral and differential cross sections for reaction of the ground F(P-2(3/2)) and excited F*(P-2(1/2)) spin-orbit states with D-2 for collision energies of 0.25 to 1.2 kilocalorie/mole. At the lowest collision energy, F* is similar to 1.6 times more reactive than F, although reaction of F* is forbidden within the Born-Oppenheimer (BO) approximation. As the collision energy increases, the BO-allowed reaction rapidly dominates. We found excellent agreement between multistate, quantum reactive scattering calculations and both the measured energy dependence of the F*/F reactivity ratio and the differential cross sections. This agreement confirms the fundamental understanding of the factors controlling electronic nonadiabaticity in abstraction reactions.