Core-Level Photoelectron Angular Distributions from Bulk-Solvated to Surface-Active Aqueous Potassium Carboxylate Salts

Photoelectron angular distributions are reported for a series of aqueous potassium carboxylate solutions, ranging from bulk-solvated to strongly surface-active species. The quantitative information determined from this work demonstrates how the measured photoelectron angular distributions are influenced by the ions' increasing propensity for the surface in aqueous solutions. Our study provides insight into the relative depth and location of the carboxylate functional group, which is valuable for investigating the adsorption of organic molecules at liquid-vapor interfaces. This work provides a further demonstration that the liquid microjet technique employed together with the measurement of photoelectron angular distributions presents a promising avenue for determining the electronic and surface properties of solutes in liquid water and at the liquid-vapor interface, information that has potential application in fields such as atmospheric chemistry, biophysics, and materials science.