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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N8—H8B⋯O1	0.90	2.16	2.922 (4)	142
N8—H8A⋯N5i	0.90	2.09	2.979 (3)	168
N7—H7A⋯N2ii	0.90	2.15	3.045 (3)	171
N7—H7B⋯O3iii	0.90	2.43	3.281 (5)	158
O4—H4D⋯N2iii	0.85	2.12	2.974 (7)	180
O4—H4C⋯O2iv	0.85	2.18	3.026 (7)	179

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