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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H2A2⋯O2A i	0.88 (2)	2.12 (3)	2.979 (2)	164 (2)
N2B—H2B1⋯O2A ii	0.86 (2)	2.26 (2)	3.055 (2)	154 (2)
N2A—H2A1⋯O3B	0.86 (2)	2.06 (2)	2.865 (2)	156 (2)
N2B—H2B2⋯O3A	0.85 (3)	2.04 (3)	2.847 (2)	159 (2)
C8A—H8AB⋯O2B ii	0.97	2.50	3.392 (2)	153
C6B—H6BB⋯O1B iii	0.97	2.57	3.430 (2)	148
C14A—H14A⋯O1A iv	0.93	2.54	3.393 (3)	153
C17B—H17B⋯O1B v	0.93	2.52	3.424 (3)	164

Symmetry codes: (i) -x+1, -y, -z+1; (ii) -x+1, -y+1, -z+1; (iii) x, y-1, z; (iv) -x+{\script{3\over 2}}, y+{\script{1\over 2}}, z; (v) -x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}.