Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯N5i	0.87	2.15	2.994 (2)	165
N4—H4N⋯O1ii	0.87	2.18	2.993 (2)	156
O1—H1O⋯N1	0.82	1.98	2.773 (2)	164
O1—H2O⋯O1iii	0.82	1.96	2.758 (2)	163

Symmetry codes: (i) ; (ii) ; (iii) .