Structure of 5-azauracil (C3H3N3O2) and its hydrolysis product

The title compounds cocrystallize in space groupP¯1:a=8.773(3),b=9.14(3),c=14.062(4) Å, =81.38(7), =71.76(3), =82.96(8)°,U=1055.5 ų,Z=4 (two independent molecules each of azauracil, its hydrolysis product, and water in the asymmetric unit). The structure was solved by direct methods and refined by full-matrix least-squares methods toR=0.059 for 2911 observed reflections. Unusually, the crystal contains both the parent molecule and its hydrolysis product in a hydrogen-bonded complex. The hydrogen bonding results in the formation of essentially planar layers of molecules which are held together by dispersion forces.