Interfacial Interactions of DCl with Salty Glycerol Solutions of KI, NaI, LiI, and NaBr

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• 作者：Annabel H. Muenter ; Jennifer L. DeZwaan ; Gilbert M. Nathanson
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：October 18, 2007
• 年：2007
• 卷：111
• 期：41
• 页码：15043 - 15052
• 全文大小：268K
• 年卷期：v.111,no.41(October 18, 2007)
• ISSN：1932-7455

文摘

Gas-liquid scattering experiments are used to explore the role of interfacial ions in controlling collisions andreactions of DCl molecules with ~2.5 M KI, NaI, LiI, and NaBr glycerol solutions. DCl molecules thatthermalize upon collision with the surface of each solution follow one of three pathways: they may desorbimmediately as DCl, undergo D H exchange in the near-interfacial region and desorb as HCl, or dissolveand dissociate in the bulk. We find that each salt amplifies the differences among the channels: the fractionof DCl molecules that desorb intact increases from 9% for pure glycerol to 18% on average for the saltsolutions, interfacial DCl HCl exchange increases from 3 to 7%, and bulk dissolution drops from 87 to75%. Dissolved ions may enhance nonreactive DCl desorption and interfacial D H exchange by tying upglycerol OH groups, which will impede both DCl-OH bonding and migration of D⁺ and H⁺ away from Cl^-after DCl ionization. Despite differences in the sizes of the ions and their interactions with the solvent, theenhancements are found to be similar for NaI, LiI, and NaBr and slightly smaller for KI. These similaritiesmay arise from an interplay between ion pairing, the strength and number of ion-solvent bonds, and ionexposure at the surface.