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

The title mol­ecular salt, C(10)H(13)N(2) (+)·C(2)H(3)O(2) (−)·0.5H(2)O, crystallized with four 2-(1H-indol-3-yl)ethanaminium cations (A, B, C and D) and four acetate anions in the asymmetric unit, together with two water mol­ecules of crystallization. Each cation is linked to an anion by a C—H⋯π inter­action. The alkyl­aminium 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 A, B, C and D, 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 b-axis direction. The chains are linked by the water mol­ecules via O(water)—H⋯O and N—H⋯O(water) hydrogen bonds, forming layers lying parallel to the bc plane. The overall inter­molecular inter­actions were investigated using Hirshfeld surfaces analysis.