Beschreibung:
<jats:p>The structure of the title compound, [K<jats:sub>2</jats:sub>(C<jats:sub>4</jats:sub>H<jats:sub>7</jats:sub>O<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>(H<jats:sub>2</jats:sub>O)]<jats:sub><jats:italic>n</jats:italic></jats:sub>, is composed of stacked sandwiches, which are formed by cation–oxygen bilayers surrounded by methylethyl hydrophobic chains. These sandwiches are held together by van der Waals interactions between the methylethyl groups. The methylethyl groups are disordered over two positions with occupancies 0.801 (3):0.199 (3). The potassium cations are coordinated by seven O atoms, which form an irregular polyhedron. There is a water molecule, the oxygen atom of which is situated in a special position on a twofold axis (Wyckoff position 4<jats:italic>e</jats:italic>). The water H atoms are involved in O<jats:sub>water</jats:sub>—H...O<jats:sub>carboxyl</jats:sub>hydrogen bonds of moderate strength. These hydrogen bonds are situated within the cation–oxygen,<jats:italic>i.e.</jats:italic>hydrophilic, bilayer.</jats:p>