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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O2i	0.79 (3)	2.13 (3)	2.914 (3)	173 (3)
N2—H2N⋯O4ii	0.80 (2)	2.21 (2)	3.006 (3)	169 (3)
N3—H3N⋯O6iii	0.83 (3)	2.03 (3)	2.854 (3)	173 (3)
N4—H4N⋯O3iv	0.75 (2)	2.21 (2)	2.960 (3)	174 (3)

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