DL-Arginine monohydrate at 100 K

Abstract

In the title compound, C6H14N4O2·H2O, the α-amino group is neutral. The molecular side chain including the guanidinium group is not fully extended, having a near gauche-gauche conformation [χ3 = 59.0 (1)°; χ4 = 72.8 (1)°]. The network of hydrogen bonds stabilizing the crystal lattice includes those formed between the deprotonated and negatively charged α-carboxylate groups and the positively charged amino groups of the guanidinium group of neighbouring molecules. N-H···O double bond C and water-mediated N-H···O hydrogen bonds link individual molecules to produce pairs of spiral motifs laterally connected by N-H···O and C-H···O hydrogen bonds.