Fig. 4: Experimentally determined acid-base equilibria of S(IV) species.
From: Direct observation of the complex S(IV) equilibria at the liquid-vapor interface
a Tautomer ratio as a function of pH. b, c pKas of the tautomeric forms. The horizontal lines depict the average values determined from XPS and Raman spectroscopy. d Concentrations of sulfur species determined via photoelectron spectroscopy. The accuracy of the pH is ±0.1. For details of the error bar of the fractions of the ions of 0.04 and the calculation of the concentration of solvated SO2, see Section 1.2.2 of the Supplementary Information. In all panels, triangles refer to Raman, full dots to photoelectron experiments, and open circles to calculated data based on photoelectron experiments.
