Bis(2,3-dimeth­oxy-10-oxostrychni­din­ium) phthalate nonahydrate

The asymmetric unit of the title compound 2C₂₃H₂₇N₂O₄⁺·C₈H₄O₄²⁻·9H₂O, contains a cation, an anionon a twofold axis and four and half mol­ecules of water, one of which is located on the twofold axis. In the cation, both fused pyrrolidine rings exhibit twisted conformations, while the piperidine rings adopt screw–boat and boat conformations. In the crystal, the components are linked by N—H...O and O—H...O hydrogen bonds. The brucinium cations form typical undulating head-to-tail ribbon structuresalong the a-axis direction, which associate with the carb­oxy phthalate and the water mol­ecules.