Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N6—H6A⋯O3ii	0.88	2.10	2.917 (4)	155
N6—H6B⋯O3iii	0.88	2.12	2.996 (4)	173
N4—H4A⋯O4i	0.88	2.25	3.101 (4)	162
N4—H4B⋯N5iv	0.88	2.21	3.066 (4)	163

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