The binary adduct of 3,6,9,16,19,22-hexaazatricyclo[22.2.2.211,14]triaconta-11,13,24,26(1),27,29-hexaene and benzene-1,2,4,5-tetracarboxylic acid.

The crystals of the title salt, 6,21-diaza-3,9,18,24-tetraazoniatricyclo[22.2.2.2(11,14)]triaconta-11,13,24,26(1),27,29-hexaene benzene-1,2,4,5-tetracarboxylate(4-) hexahydrate, C(24)H(42)N(6)(4+) x C(10)H(2)O(8)(4-) x 6H(2)O, are formed by the intermolecular interaction of a macrocyclic hexamine with a molecule of C(6)H(2)(COOH)(4) in aqueous solution. Both the cation and the anion are on inversion centres. Hydrogen bonds are formed between the four ammonium cations in the hexamine and the four carboxylate anions in the aromatic acid. Stacks exist along the crystallographic a axis in the solid state. The water molecules also take part in a hydrogen-bonding network which joins these stacks together.