L-prolinium tartrate

In the title salt, C5H10NO2+.C4H5O6-, proline exists as a cation and the ta rtaric acid as a semi-tartrate anion. The semi-tartrate ions form hydrogen- bonded strings along the c axis. These strings are interconnected through t he proline molecules, forming a layered network parallel to the bc plane. T he proline molecules, however, do not directly interact among themselves, e xcept for a weak C-H . . .O hydrogen bond.