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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O1i	1.22 (1)	1.22 (1)	2.432 (5)	180 (1)
O4—H2⋯O4ii	1.15 (6)	1.45 (5)	2.441 (5)	139 (4)
N2—H2B⋯O5iii	0.90	2.22	2.850 (5)	127
O7—H3⋯O2i	0.98 (2)	1.95 (5)	2.805 (6)	144 (6)
O7—H4⋯O3iv	0.98 (2)	1.85 (4)	2.771 (6)	154 (7)

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