The structure of aqueous solutions of tetraethylammonium chloride was investigated using compressibility and density measurements
and positron annihilation methods. The experimental results are different from those obtained earlier for systems where hydrophobic
hydration dominates, although some evidences for formation of cage-like hydrates in liquid phase were observed. The results
are interpreted, among others, in terms of competition among different hydrates of the tetraethylammonium cations, hydration
of chloride anions, and formation of ionic pairs.