Crystal structure and Hirshfeld surface analysis of 2-(1-indol-3-yl)ethanaminium acetate hemihydrate.

The title mol-ecular salt, CHN ·CHO ·0.5HO, crystallized with four 2-(1-indol-3-yl)ethanaminium cations (, , and ) and four acetate anions in the asymmetric unit, together with two water mol-ecules of crystallization. Each cation is linked to an anion by a C-H⋯π inter-action. The alkyl-aminium side chains have folded conformations, with N-C-C-C torsion angles of -58.5 (3), 59.5 (3), -64.6 (3) and -56.0 (3)° for cations , , and , respectively. In the crystal, the cations and anions are liked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains propagating along the -axis direction. The chains are linked by the water mol-ecules O-H⋯O and N-H⋯O hydrogen bonds, forming layers lying parallel to the plane. The overall inter-molecular inter-actions were investigated using Hirshfeld surfaces analysis.