Crystal structure of (S)-sec-butyl-ammonium l-tartrate monohydrate

The title hydrated mol-ecular salt, C₄H₁₂N⁺·C₄H₅O₆^-·H₂O, was prepared by deprotonation of enanti-opure l-tartaric acid with racemic sec-butyl-amine in water. Only one enanti-omer was observed crystallographically, resulting from the combination of (S)-sec-butyl-amine with l-tartaric acid. The sec-butyl-ammonium moiety is disordered over two conformations related by rotation around the CH-CH₂ bond; the refined occupancy ratio is 0.68 (1):0.32 (1). In the crystal, mol-ecules are linked through a network of O-H⋯O and N-H⋯O hydrogen-bonding inter-actions, between the ammonium H atoms, the tartrate hy-droxy H atoms, and the inter-stitial water, forming a three-dimensional supra-molecular structure.