2,3-Dimeth­oxy-10-oxostrychnidinium hydrogen oxalate dihydrate

In the cation of the title salt, C₂₃H₂₇N₂O₄⁺·C₂HO₄⁻·2H₂O, both fused pyrrolidine rings exhibit twisted conformations, while the piperidine rings adopt screw-boat and boat conformations. In the crystal, the three components are linked via O—H...O and N—H...O inter­actions, forming a tape along the b axis. The tapes are further linked by weak C—H...O hydrogen bonds. forming a three-dimensional network.

4-(4-Bromo­styr­yl)-1-methylpyridinium tosyl­ate

In the cation of the title compound, C₁₄H₁₃BrN⁺·C₇H₇O₃S⁻, the dihedral angle between the benzene and pyridine rings is 8.34 (11)°. The Br atom is disordered over two positions with site occupancies of 0.74 (2) and 0.26 (2). The mol­ecular structure is stabilized by a weak intra­molecular C—H...O inter­actions. The crystal structure exhibits weak C—H...O and π–π [centroid–centroid distance = 3.7466 (17) Å] inter­actions, forming a three dimensional network.

4-[2-(4-But­oxy­phen­yl)ethen­yl]-1-methyl­pyridinium tosylate

In the title mol­ecular salt, C₁₈H₂₂NO⁺·C₇H₇O₃S⁻, the dihedral angle between the aromatic rings in the cation is 10.00 (9)°; its alkyl side chain adopts an extended conformation. In the crystal, weak C—H...O and π–π [centroid–centroid distance = 3.7658 (17) Å] inter­actions link the components, generating a three-dimensional network.

2,4,6-Tri­amino-1,3,5-triazin-1-ium 3-(prop-2-eno­yloxy)propano­ate acrylic acid monosolvate monohydrate

The asymmetric unit of the title salt, C₃H₇N₆⁺·C₆H₇O₄⁻·C₃H₄O₂·H₂O, contains a 2,4,6-tri­amino-1,3,5-triazin-1-ium cation, a 3-(prop-2-eno­yloxy)propano­ate anion and acrylic acid and water solvent mol­ecules in a 1:1:1:1 ratio and with each species in a general position. In the crystal, the components are linked into a supra­molecular layer in the bc plane via a combination of O—H...O, N—H...N and N—H...O hydrogen bonding. The crystal studied was a non-merohedral twin, the minor component contribution being approximately 26%.

2-Phenyl­ethanaminium 4-hy­droxy­benzoate

In the title salt, C₈H₁₂N⁺·C₇H₅O₃⁻, the cation is disordered over two orientations with site occupancies of 0.565 (7) and 0.435 (7). In the anion, the carboxyl­ate group makes the dihedral angle of 4.19 (18)° with the benzene ring. In the crystal, the ions are connected by N—H...O and O—H...O hydrogen bonds, forming a three-dimensional network.