Threading competitive

Because earlier reviews deal explicitly with these template effects [4, 7, 12], the following discussion is restricted to a recently discovered anion template effect (Scheme 6.5.3). fn non-competitive solvents, the tetralactam macrocyde strongly binds anions such as chloride, bromide, or phenolate. Phenolate stoppers bound to the macrocycle can act as wheeled nudeophiles and react through the wheel with a semi-axle generated in situ to yield ether rotaxanes in yields of 57% to 95% [13]. Consequently, the macrocyde not only represents an anion receptor, but as a concave template simultaneously provides the correct orientation of the guest for threading the axle into the wheel. 

Fig. 11. The chemically controlled competition between two thread-like species 18 and 19 for the cavity of a tetracationic cyclophane 44+.

As it runs like a thread through the present treatment, various cancellations and competitions (enthalpy/entropy, repulsion/attraction, etc.) appear to be conspiring to make molecular behavior in complex fluids seemingly simple. 

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