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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O3	0.84 (2)	2.11 (2)	2.950 (3)	176 (3)
N2—H2N⋯O4i	0.87 (2)	2.11 (2)	2.961 (3)	169 (3)
N3—H3N⋯O1ii	0.85 (2)	2.09 (2)	2.939 (3)	173 (2)
N4—H4N⋯O2	0.85 (2)	2.12 (2)	2.947 (3)	168 (3)

Symmetry codes: (i) ; (ii) .