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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯N4i	0.86	1.93	2.7761 (15)	168
N3—H3N⋯N2	0.86	1.96	2.8053 (16)	168

Symmetry code: (i) .