Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106-9510, USA.
Phys Chem Chem Phys. 2011 May 14;13(18):8153-62. doi: 10.1039/c0cp01418d. Epub 2010 Nov 3.
Here we extend a recently introduced state-to-state kinetic model describing single- and multi-quantum vibrational excitation of molecular beams of NO scattering from a Au(111) metal surface. We derive an analytical expression for the rate of electronically non-adiabatic vibrational energy transfer, which is then employed in the analysis of the temperature dependence of the kinetics of direct overtone and two-step sequential energy transfer mechanisms. We show that the Arrhenius surface temperature dependence for vibrational excitation probability reported in many previous studies emerges as a low temperature limit of a more general solution that describes the approach to thermal equilibrium in the limit of infinite interaction time and that the pre-exponential term of the Arrhenius expression can be used not only to distinguish between the direct overtone and sequential mechanisms, but also to deduce their relative contributions. We also apply the analytical expression for the vibrational energy transfer rates introduced in this work to the full kinetic model and obtain an excellent fit to experimental data, the results of which show how to extract numerical values of the molecule-surface coupling strength and its fundamental properties.
在这里，我们扩展了最近提出的一种态态动力学模型，该模型描述了 NO 分子束从 Au(111)金属表面散射的单量子和多量子振动激发。我们推导出了非绝热电子振动能量转移率的解析表达式，然后将其用于分析直接泛频和两步顺序能量转移机制的动力学的温度依赖性。我们表明，许多先前研究中报告的振动激发概率的 Arrhenius 表面温度依赖性是更一般解的低温极限，该解描述了在无限相互作用时间极限下达到热平衡的情况，并且 Arrhenius 表达式的指数前因子不仅可用于区分直接泛频和顺序机制，还可用于推断它们的相对贡献。我们还将本文中引入的振动能量转移率的解析表达式应用于完整的动力学模型，并与实验数据非常吻合，结果表明如何提取分子-表面耦合强度及其基本性质的数值。
