Energiebänder der tunnelnden Überschuß-Protonen in flüssigen Säuren. Eine IR-spektroskopische Untersuchung der Natur der Gruppierungen H5O2+

We investigated 5 μ thick films of polystyrene sulphonic acid. Ill-spectrograms were taken in the range of 4000—650 cm-1 as a function of the degree of hydration of the films; water adsorption isotherms were plotted and the change in length of the films on hydration was measured. The investigations showed that the proton is removed from the anion in the presence of two water molecules. Study of the bands of water of hydration and of an IR-continuous absorption gave the following results : The excess proton is mobile by tunneling in the hydrogen bridge of the H502+ group. The latter is therefore to be represented by the two proton boundary structures in fig. 16. The two water molecules in this group retain there individuality as vibrating groups. The tunneling of the excess proton in the iï502+ group is closely connected with the occurrence of an IR-continuous absorption. This indicates that the tunneling protons are present in energy bands. The latter arise by coupling of the tunneling protons by proton dispersion forces. The discussion shows that the structure diffusion of groups of the size Hò02+ is sufficient to account for the anomalous proton conductivity.