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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2i	0.87 (2)	1.89 (2)	2.7509 (13)	173.2 (19)
O2—H2⋯O1	0.86 (2)	1.80 (2)	2.4510 (14)	131.0 (19)

Symmetry code: (i) .