(R)-1-Phenylethylammonium 6-amino-5-nitropyrimidine-2,4(1H,3H)-dionate (R)-1-phenylethylamine hemisolvate: hydrogen-bonded sheets of ions with pendent solvent molecules.

In the title compound, 2C(8)H(12)N(+).2C(4)H(3)N(4)O(4)(-).C(8)H(11)N, the anions are linked by paired N-H...N hydrogen bonds [H.N = 2.07 and 2.11 A, N.N = 2.942 (3) and 2.978 (3) A and N-H.N = 173 and 170 degrees] and by paired N-H...O hydrogen bonds [H.O = 1.98 and 2.05 A, N...O = 2.855 (3) and 2.917 (3) A, and N-H...O = 173 and 167 degrees ] into chains of rings. These chains are linked into sheets by further N-H...O hydrogen bonds in which all of the donors are provided by the cations [H....O = 1.83-2.17 A, N...O = 2.747 (3)-2.965 (3) A and N-H...O = 141-168 degrees]. The neutral amine molecule is pendent from the sheet and is linked to it by a single N-H...N hydrogen bond [H...N = 2.00 A, N...N = 2.901 (3) A and N-H...N = 175 degrees].