Crystal structure of 2-phenyl-ethanaminium 3-carb-oxy-prop-2-enoate.

The title mol-ecular salt, C8H12N(+)·C4H3O4 (-), crystallized with two independent cations and anions in the asymmetric unit. The ethanaminium side chains of the cations exhibit anti conformations [C-C-C-N torsion angles = 176.5 (3) and -179.4 (3)°]. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds connect adjacent anions and cations, and , O-H⋯O hydrogen bonds connect adjacent anions, generating sheets parallel to (001).

Crystal structure of piperidinium 4-nitro-phenolate.

In the title mol-ecular salt, C5H12N(+)·C6H4NO3 (-), the piperidine ring adopts a chair conformation and the cation is protonated at the N atom. In the anion, the nitro group is twisted at an angle of 10.30 (11)° with respect to the attached benzene ring. In the crystal, N-H⋯O hydrogen bonds link adjacent anions and cations into infinite chains propagating along [100]. The chains are linked by C-H⋯π inter-actions, forming sheets lying parallel to (001).

Crystal structure of 2-phenyl-ethyl-amin-ium 4-nitro-phenolate monohydrate.

In the title hydrated mol-ecular salt, C8H12N(+)·C6H4NO3 (-)·H2O, the conformation of the side chain in the cation is anti [C-C-C-N = 179.62 (12)°] and the dihedral angle between the aromatic ring and the nitro group in the anion is 3.34 (11)°. In the crystal, the components are linked by O-H⋯O and N-H⋯O hydrogen bonds, generating (10-1) sheets, which feature R 4 (4)(21) loops. The sheets inter-act by weak aromatic π-π stacking inter-actions [centroid-centroid distance = 3.896 (3) Å], forming a three-dimensional network.