Benzyltrimethylammonium hydroxide trihydrate containing hydroxide--water layers.

In the title compound, C(10)H(16)N(+) x OH(-) x 3H(2)O, two-dimensional bilayer-like arrays of organic cations and corrugated anionic hydroxide-water layers are stacked alternately along the c axis. All hydroxide and water H atoms are in ordered positions, giving rise to a network of hydrogen bonds [O...O 2.639 (2)--2.927 (2) A for water donors and O...O 3.323 (2) A for hydroxide donors] with four- and six-membered rings.