Lu Yu-Ju, Liang Chi-Wei, Lin Jim J
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
J Chem Phys. 2006 Oct 7;125(13):133121. doi: 10.1063/1.2202828.
The reaction of oxygen atom in its first singlet excited state with nitrous oxide was investigated under the crossed molecular beam condition. This reaction has two major product channels, NO+NO and N2+O2. The product translational energy distributions and angular distributions of both channels were determined. Using oxygen-18 isotope labeled O(1D) reactant, the newly formed NO can be distinguished from the remaining NO that was contained in the reactant N2O. Both channels have asymmetric and forward-biased angular distributions, suggesting that there is no long-lived collision complex with lifetime longer than its rotational period. The translational energy release of the N2+O2 channel (fT = 0.57) is much higher than that of the NO+NO channel (fT = 0.31). The product energy partitioning into translational, rotational, and vibrational degrees of freedom is discussed to learn more about the reaction mechanism. The branching ratio between the two product channels was estimated. The 46N2O product of the isotope exchange channel, 18O+44N2O-->16O+46N2O, was below the detection limit and therefore, the upper limit of its yield was estimated to be 0.8%.
在交叉分子束条件下研究了处于第一单线态激发态的氧原子与一氧化二氮的反应。该反应有两个主要产物通道，即NO + NO和N₂ + O₂。测定了两个通道的产物平动能分布和角分布。使用氧 - 18同位素标记的O(¹D)反应物，可以将新形成的NO与反应物N₂O中所含的剩余NO区分开来。两个通道都具有不对称且向前偏向的角分布，这表明不存在寿命长于其转动周期的长寿命碰撞复合物。N₂ + O₂通道的平动能释放（fT = 0.57）远高于NO + NO通道（fT = 0.31）。讨论了产物能量在平动、转动和振动自由度之间的分配，以更多地了解反应机理。估计了两个产物通道之间的分支比。同位素交换通道18O + 44N₂O→16O + 46N₂O的46N₂O产物低于检测限，因此，估计其产率的上限为0.8%。
