Graduate School of Material Science, University of Hyogo, Kohto, Kamigori, Hyogo 678-1297, Japan.
J Chem Phys. 2012 Jan 21;136(3):034301. doi: 10.1063/1.3676724.
The oxidation reaction dynamics of gas-phase molybdenum atoms by oxygen molecules was studied under a crossed-beam condition. The product MoO was detected by a time-of-flight mass spectrometer combined with laser multi-photon ionization. An acceleration lens system designed for the ion-velocity mapping condition, a two-dimensional (2D) detector, and a time-slicing technique were used to obtain the velocity and angular distributions of the products at three collision energies: 10.0, 17.8, and 50.0 kJ/mol. The angular distributions showed forward and backward peaks, whose relative intensities changed by the collision energy. While two peaks had similar intensities at low collision energies, the forward peak became dominant at the highest collision energy, 50 kJ/mol. The product kinetic energy distributions showed a good correlation with the initial collision energies, i.e., almost the same energy as the collision energy appeared as the product kinetic energy. These results suggested that the reaction proceeds via an intermediate complex, and the lifetime of the complex becomes shorter than its rotational period at high collision energy.
在交叉束条件下研究了气相钼原子与氧分子之间的氧化反应动力学。通过飞行时间质谱仪结合激光多光子电离检测到产物 MoO。设计了用于离子速度成像条件的加速透镜系统、二维（2D）探测器和时间切片技术，以在三个碰撞能下获得产物的速度和角分布：10.0、17.8 和 50.0 kJ/mol。角分布显示出前向和后向峰，其相对强度随碰撞能而变化。虽然在低碰撞能下两个峰的强度相似，但在最高碰撞能 50 kJ/mol 时，前向峰占主导地位。产物的动能分布与初始碰撞能有很好的相关性，即产物动能几乎与碰撞能相同。这些结果表明，反应通过中间复合物进行，并且在高碰撞能下，复合物的寿命短于其旋转周期。
