Enhanced Concentration of Polarizable Anions at the Liquid Water Surface: SHG Spectroscopy and MD Simulations of Sodium Thiocyanide

摘要: Contrasting current textbook descriptions, a consistent picture of substantial concentration enhancement highly polarizable anions at the surface aqueous electrolyte solutions is emerging. Such may have important implications for chemistry occurring on aerosols and ocean surfaces. Here we present combined experimental theoretical investigation liquid/air interface sodium thiocyanide varying salt concentrations. Normalized second harmonic generation intensities fitted to Langmuir isotherms yield Gibbs free energy adsorption −1.80 kcal/mol. These results are in accord with molecular dynamics simulations slab geometry, which predict an appreciable SCN-.