Stereodynamics in state-resolved scattering at the gas-liquid interface
Stereodynamics in state-resolved scattering at the gas-liquid interface
复制标题
DOI：
10.1073/pnas.0800401105
复制
发表时间：
2008-09-02
影响因子：
11.1
通讯作者：
Nesbitt, David J.
中科院分区：
文献类型：
--
作者：
Perkins, Bradford G., Jr.;Nesbitt, David J.
气液界面的立体动力学提供了对直接影响表面和本体液体内的非均相化学的重要物理相互作用的深入了解。本文研究了真空条件下（入射能量E-inc = 10.6（8）kcal/mol，入射角θ（inc）= 60 °），CO2在液体全氟聚醚（PFPE）表面的分子束散射。在实验上，利用高分辨率偏振调制红外激光光谱探测了内量子态布居和M-J分布。J态粒子数的分析揭示了双通道散射动力学，其特征在于捕获-解吸和脉冲散射的两个温度玻尔兹曼分布。此外，分子动力学模拟的CO2 +氟化自组装单分子膜已被用来模拟CO2 + PFPE动力学。实验结果和分子动力学模拟揭示了高度取向的CO2分布，优先散射与“顶自旋”作为一个强烈的J状态的函数增加。
Stereodynamics at the gas-liquid interface provides insight into the important physical interactions that directly influence heterogeneous chemistry at the surface and within the bulk liquid. We investigate molecular beam scattering Of CO2 from a liquid perfluoropolyether (PFPE) surface in vacuum [incident energy E-inc = 10.6(8) kcal/mol, incident angle theta(inc) = 60 degrees] to specifically reveal rotational angular-momentum directions for scattered molecules. Experimentally, internal quantum state populations and M-J distributions are probed by high-resolution polarization-modulated infrared laser spectroscopy. Analysis of J-state populations reveals dual-channel scattering dynamics characterized by a two-temperature Boltzmann distribution for trapping-desorption and impulsive scattering. In addition, molecular dynamics simulations of CO2 + fluorinated self-assembled monolayers have been used to model CO2 + PFPE dynamics. Experimental results and molecular dynamics simulations reveal highly oriented CO2 distributions that preferentially scatter with "top spin" as a strongly increasing function of J state.