L-Proline Monohydrate at 100 K

A new crystalline modification of proline was identified by the present X-ray analysis as a monoclinic L-proline monohydrate, C₅H₉NO₂.H₂O. The pyrrolidine rings are in a C₂.C^γ-exo-C^δ-endo conformation. The C4 atom (C^γ) is in a trans position with respect to the carboxyl group. In the crystal lattice, columns of L-proline molecules are stabilized by intermolecular hydrogen bonds. These columns are interconnected by water molecules. The water molecules in the structure form non-linear hydrogen-bonded chains parallel to the c axis. One H atom of the water molecule chain is disordered.

-1