The tetrabutylammonium cation is a large, bulky cation that is only weakly solvated by water molecules. This is because the water molecules cannot get close enough to the cation to form strong hydrogen bonds. In contrast, the tetrabutylammonium cation is strongly solvated by solvents of low polarity, such as hexane. This is because the hexane molecules can get close to the cation and form van der Waals forces. These van der Waals forces are weaker than hydrogen bonds, but they are still strong enough to hold the tetrabutylammonium cation in solution.

In addition, the tetrabutylammonium cation is also lipophilic, which means that it is attracted to nonpolar solvents. This is because the tetrabutylammonium cation has a hydrocarbon chain that is similar to the hydrocarbon chains in nonpolar solvents. The hydrocarbon chain of the tetrabutylammonium cation can interact with the hydrocarbon chains of the nonpolar solvent molecules, which increases the solubility of the tetrabutylammonium cation in the nonpolar solvent.