Isomorphous brucinium 4-nitro­benzoate methanol solvate and brucinium 4-nitro­benzoate dihydrate

In isomorphous crystals of brucinium 4-nitro­benzoate methanol solvate, C₂₃H₂₇N₂O₄⁺·C₇H₄NO₄^-·CH₃OH, and brucinium 4-nitro­benzoate dihydrate, C₂₃H₂₇N₂O₄⁺·C₇H₄NO₄^-·2H₂O, the brucinium cations form reverse corrugated layers, in which the amine N and amide O atoms of the brucinium cations are located in the grooves and at convex points of the layer surface, respectively. Similarly, as observed for the commonly occurring corrugated brucinium layers, the amide O atoms of the cations are involved in hydrogen bonds in which solvent mol­ecules are the donors.