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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1B—H1B⋯O1Ai	0.954 (18)	1.802 (18)	2.7526 (16)	174.0 (15)
N1A—H1A⋯N2Bii	0.915 (19)	1.95 (2)	2.8544 (18)	171.5 (16)

Symmetry codes: (i) ; (ii) .