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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O3	0.84	1.83	2.662 (3)	170
O2—H2⋯O4	0.84	1.82	2.655 (4)	170
O3—H3⋯O2	0.84	1.88	2.711 (3)	173
O4—H4⋯O1i	0.84	1.90	2.736 (4)	178

Symmetry code: (i) .