Bis{(R)-1-(3-amino­sulfonyl-4-meth­oxy­phen­yl)-N-[2-(2-eth­oxy­phen­oxy)eth­yl]propan-2-aminium} adipate tetra­hydrate

The title compound, 2C₂₀H₂₉N₂O₅S⁺·C₆H₈O₄²⁻·4H₂O, which was found to be optically active, is a relatively rare example of a chiral compound crystallizing in the triclinic crystal system. The dihedral angles between the phenyl rings of the cations are 60.03 (15) and 62.03 (16)°, while the C atoms of the anion are almost coplanar (r.m.s. deviation 0.085 Å) and all trans to each other. In the crystal, the components are connected by an extensive network of N—H...O and O—H...O hydrogen bonds. The sulfonamide groups link the cations into pairs via two N—H...O hydrogen bonds about the pseudo-inversion centre, leading to the formation of R₂²(8) rings. The anions are stacked in between four cationic pairs. Pairs of water mol­ecules bridge the larger building units, forming hydrogen bonds with the remaining two O atoms of the anion.