Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N1H1ECl1	0.89	2.33	3.169(3)	156
C3H3AO3i	0.97	2.58	3.428(4)	147
N1H1DCl1ii	0.89	2.24	3.116(3)	169
N1H1FCl1iii	0.89	2.26	3.139(3)	171
C2H2AO2iv	0.98	2.44	3.186(4)	133
C4H4BO3v	0.96	2.50	3.250(4)	135
C4H4CO2vi	0.96	2.51	3.438(5)	163

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