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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O4i	0.76 (4)	2.15 (4)	2.882 (4)	165.09
N3—H3⋯N4ii	0.78 (4)	2.10 (4)	2.868 (5)	168.21
N6—H6⋯O6iii	0.83 (4)	2.26 (4)	2.998 (4)	147.35
N5—H5⋯N1iv	0.83 (4)	2.03 (4)	2.847 (4)	168.32
N3—H3⋯O1	0.78 (4)	2.49 (4)	2.732 (4)	100 (3)

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