Supramolecular polarization modes

Further work to clarify the exact mechanism by which shape and polarity matching influences co-crystal formation will undoubtedly lead to improvements in the co-former selection strategy presented here. Experimental results that apparently contradict these principles may uncover new supramolecular recognition modes, as illustrated by the co-crystallisation of steroids with aromatic compounds, or help identify further factors that need to be considered in co-crystal design. 

Figure 35 Supramolecular isomerism—influence of solvent, (a) Chemical structure of the basic building block, copper(I) 2-ethylimidazolate, (b) supramolecular chain isolated from a polar solvent, (c) triple-stranded helix shown in space Ailing mode resulting from the combination of three symmetry-related chains illustrated in (b), and (d) zigzag chain obtained from a less-polar solvent.

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