Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
J Phys Chem A. 2012 Aug 2;116(30):7791-6. doi: 10.1021/jp305241e. Epub 2012 Jul 23.
The linear kinetic analysis called the integrated profiles method (IPM) makes it simple to analyze the multistep relaxation processes of vibrational manifold. The problem that plots for linear regression in the IPM analysis cannot be made, however, has been found in the study of self relaxation of O2(X3Σ(-)g, v = 6-8). The cause of the problem is the identical time-dependence of the populations of the adjacent vibrational levels. An addition of CF4 into the system made a difference in the time profiles and enabled us to make IPM analysis and determine the rate coefficients. In the experiments, a gaseous mixture of O3/O2/CF4 in an Ar carrier at 298 K was irradiated at 266 nm, and the direct photoproduct O2(X3Σ(-)g, v = 6-9) from O3 was detected by laser-induced fluorescence (LIF)in the B3Σu-X3Σ(-)g transition. Time-resolved LIF intensities of O2(X3Σ(-)g, v) at various pressures of O2 and fixed pressure of CF4 were recorded. The resulting rate coefficients for v = 6−8 correlate smoothly with those for v ≤ 5 and v ≥ 8 reported previously.The vibrational-level dependence (v = 2-13) of the rate coefficients for relaxation of O2(X3Σ(-)g, v) by O2 is accounted for by the balance between the harmonic transition probabilities and the energy defect in the V-V energy-transfer mechanism.
线性动力学分析称为积分谱法（IPM），它使得分析振动子的多步弛豫过程变得简单。然而，在研究 O2(X3Σ(-)g，v=6-8)的自弛豫时，发现 IPM 分析中的线性回归图无法绘制。问题的原因是相邻振动能级的布居数具有相同的时间依赖性。向系统中添加 CF4 会改变时间分布，使我们能够进行 IPM 分析并确定速率系数。在实验中，在 298 K 的 Ar 载体中，臭氧/氧气/CF4 的混合气体在 266nm 处被辐照，来自 O3 的直接光产物 O2(X3Σ(-)g，v=6-9)通过激光诱导荧光（LIF）在 B3Σu-X3Σ(-)g 跃迁中被检测到。记录了各种 O2 压力和固定 CF4 压力下 O2(X3Σ(-)g，v)的时间分辨 LIF 强度。v=6-8 的速率系数与先前报道的 v≤5 和 v≥8 的速率系数很好地相关。O2(X3Σ(-)g，v)通过 O2 弛豫的速率系数随振动能级（v=2-13）的变化可以通过 V-V 能量转移机制中的谐频跃迁概率和能量缺陷之间的平衡来解释。
