Multidimensional reactions present various channels that can exhibit very different dynamics and give products of varying subsequent reactivity. Here, we present a combination of experiment and theory to reveal the dynamics of hydrogen abstraction by OH radical at primary and secondary sites in n-butane at a collision energy of 8 kcal/mol. Crossed molecular beam slice imaging experiments unequivocally probe the secondary abstraction channel showing backward angular distributions with mild energy release to product translation, which are accurately captured by trajectory calculations using a specific-reaction-parameter Hamiltonian. Experiments containing both reaction channels indicate a less marked backward character in the angular distribution, whose origin is shown by trajectory calculations to appear as an evolution toward more sideways scattering from the secondary to primary channel. While the two channels have markedly different angular distributions, their energy release is largely comparable, showing ample energy release into the water product. The synergistic combination of crossed-beam imaging and trajectories opens the door to detailed reaction-dynamics studies of chemical reactions with ever-increasing complexity.

中文翻译：

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交叉束切片成像和准经典轨迹计算揭示了OH +正丁烷反应中的多通道动力学。

多维反应呈现出各种通道，这些通道可以展现出截然不同的动力学特性，并提供具有不同后续反应性的产物。在这里，我们提出实验和理论的结合，以揭示OH自由基在n原子的一级和二级位置上夺氢的动力学。-丁烷的碰撞能量为8 kcal / mol。交叉分子束切片成像实验明确地探测了次要抽象通道，该通道显示出向后的角度分布，并向产品平移释放了适度的能量，通过使用特定反应参数哈密顿量的轨迹计算可以准确地捕获这些通道。包含两个反应通道的实验表明，角度分布的后向特征较少，其轨迹显示通过从次级通道到初级通道向更多侧向散射的演变来显示其原点。尽管两个通道的角度分布明显不同，但它们的能量释放在很大程度上是可比的，表明有足够的能量释放到水产品中。