Laboratoire de Chimie-Physique, Matière et Rayonnement, Université Pierre-et-Marie Curie (UPMC-Univ Paris 06) and CNRS (UMR 7614), 11 rue Pierre-et-Marie-Curie, 75231 Paris Cedex 05, France.
Phys Chem Chem Phys. 2011 Apr 21;13(15):7142-8. doi: 10.1039/c0cp02864a. Epub 2011 Mar 15.
The reaction of HCl on water ice provides a simple case for understanding dissociation and proton transfer in this non-optimal, incomplete solvation environment, playing a central role in atmospheric chemistry. This reaction has been repeatedly reported as thermally dependent, whereas the theoretical models predict a spontaneous dissociation. We examine the adsorption of HCl on ice at low temperature (50 K and 90 K) via a combination of near-edge X-ray absorption spectroscopy (NEXAFS) at the chlorine L-edge, photoemission (XPS and UPS), and reflection-adsorption infrared spectroscopy (FT-RAIRS). We show the complete dissociation of HCl into Cl(-) and H(+) through 3 hydrogen bonds, predominantly by direct reaction with water (80%) and by self-solvation (20%), in full agreement with the prediction of a barrierless process.
HCl 在水冰上的反应为理解非最优、不完全溶剂化环境中的离解和质子转移提供了一个简单的案例，在大气化学中起着核心作用。该反应已被反复报道为热依赖性的，而理论模型预测其为自发离解。我们通过氯 L 边近边 X 射线吸收光谱（NEXAFS）、光电子发射（XPS 和 UPS）和反射吸附红外光谱（FT-RAIRS）组合，在低温（50 K 和 90 K）下研究了 HCl 在冰上的吸附。我们通过 3 个氢键展示了 HCl 完全离解为 Cl(-) 和 H(+)，主要通过直接与水（80%）和自溶剂化（20%）反应，完全符合无势垒过程的预测。
