Figure 9
Comparison of the hydrogen-bonded networks present in crystals of 7 (upper), (7)2·(2) (centre), and (5)2·(6) (lower) and looking down the threefold screw axes. Only one enantiomer (dark green) is present in structure 7, but both enantiomers (light and dark green) are present in compound (7)2·(2). Only achiral molecules are contained in (5)2·(6). The molecules of isomer 5 (light and dark blue) occupy a general position, whereas those of isomer 6 major component (yellow and orange) are equally distributed across a centre of symmetry. |