Tying Molecules in Knots

We are now left with another question - what is this new structure that we have drawn with the three crossing points However we twist and turn the molecule (hint try this with pipe-cleaners) the crossing points remain. If we start at any point on the structure and trace around we eventually end up at the same point. In other words, there is only a single cyclic molecule, but the twisting means that it is not the same as the [2+2] macrocyclic product. This view serves to emphasise the relationship with the double-helical structures that 

7 The Three-Dimensional Template Effect, Supramolecular Chemistry and Molecular Topology 

We have come to the end of our journey through supramolecular chemistry. The bulk of the discussion in this chapter has centred upon the role of the metal ion in controlling the conformation of a co-ordinated ligand. We have seen that a variety of novel molecular architectures may be achieved from the simple principles that we have developed. 

Many of the references quoted in Chapter 6 contain relevant material. 

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