Supramolecular Hydrogen-Bond Motifs in Chiral and Racemic Molecular Salts: A Comparison of (S)-2-Methyl Piperizinium Hydrogen Phosphite Monohydrate, C5H14N2·HPO3·H2O and (R,S)-2-Methyl Piperizinium Hydrogen Phosphite 2.23 Hydrate, C5H14N2·HPO3·2.23H2O

The crystal structures of C 5H 14N 2·HPO 3·H 2O ( 1) and C 5H 14N 2·HPO 3·2.23H 2O ( 2) are described and compared. Compound 1 contains homochiral ( S)-2-methyl piperizinium cations, hydrogen phosphite ions and water molecules. The components are linked by N–H？O and O–H？O hydrogen bonds into a three-dimensional network. In compound 2, racemic ( R, S)-2-methyl piperizinium cations combine with the same anions and water molecules to generate a far more complex, high symmetry “supramolecular” structure, which features distinctive R 6 6(12) loops and helical C(2) chain hydrogen-bonding motifs involving the water molecules. Crystal data: 1 (C 5H 17N 2O 4P), M r = 200.18, orthorhombic, P2 12 12 1 (No. 19), Z = 4, a = 8.564 (5) ？, b = 9.593 (6) ？, c = 11.607 (6) ？, V = 953.6 (9) ？ 3, R( F) = 0.066, wR( F 2) = 0.081. 2 (C 5H 19.47N 2O 5.24P), M r = 222.49, trigonal, (No. 148), Z = 18, a = 31.075 (2) ？, c = 6.1875 (4) ？, V = 5174.5 (6) ？ 3, R( F) = 0.044, wR( F 2) = 0.107.