Ir study of the structure of palladium(ii) acetate in chloroform, acetic acid, and their mixtures in solution and in liquid-solid subsurface layers

It is found that cyclic trimer I and linear dimer II are the molecular states of palladium(II) acetate in its 1. 10-3-0.7 M chloroform solutions. The mole fraction of dimer II is higher in dilute solutions. Even with small acetic acid (HOAc) additions the I↔II equilibrium is shifted toward I because of the variation of the composition of the outer-spheric solvation shells. The content of II in the 0.1 M solution of PdAc2 in 50 vol. % HOAc+CHCl3 is 10%. However, in the thin subsurface layers of this solution at the interface CaF2 -solution, the I↔ equilibrium is slowly shifted toward II whose concentration after 60 min is 22%. This may be caused by structuring of the liquid phase in the subsurface layers during the measured time.