Crystal structure of 1,2,3,4-tetra-hydro-isoquinolin-2-ium (2 S ,3 S )-3-carb-oxy-2,3-di-hydroxy-propano-ate monohydrate.

The crystal structure of 1,2,3,4-tetra-hydro-isoquinolin-2-ium (2 S ,3 S )-3-carb-oxy-2,3-di-hydroxy-propano-ate monohydrate, C 9 H 12 N + ·C 4 H 5 O 6 - ·H 2 O, at 115 K shows ortho-rhom-bic symmetry (space group P 2 1 2 1 2 1 ). The hydrogen tartrate anions and solvent water mol-ecules form an intricate diperiodic O-H⋯O hydrogen-bond network parallel to (001). The tetra-hydro-isoquinolinium cations are tethered to the anionic hydrogen-bonded layers through N-H⋯O hydrogen bonds. The crystal packing in the third direction is achieved through van der Waals contacts between the hydro-carbon tails of the tetra-hydro-isoquinolinium cations, resulting in hydro-phobic and hydro-philic regions in the crystal structure.