Table 1. Hydrogen-bond geometry (, ).

Cg1 is the centroid of the N1/N2/C1C3 ring.

DHA	DH	HA	D A	DHA
O2H2O3i	0.82	1.86	2.6718(17)	170
O3H3N1ii	0.82	2.04	2.8377(19)	166
C19H19BO1iii	0.96	2.46	3.355(3)	155
C24H24O2iv	0.93	2.57	3.482(3)	167
C19H19C Cg1ii	0.96	2.53	3.422(2)	154

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