Physical Studies of Template Reactions

Template reactions have been monitored by NMR spectroscopy (126) for the reaction of Na + ions with dibenzo-18-crown-6 in TV,N-dimethyl-formamide. One drawback of this technique is that the presence of paramagnetic ions, i.e., many transition metal ions, would cause appreciable broadening of the resonances. 

The driving force toward formation of a macrocycle has been related to stability constants by Cabbiness and Margerum (25). In aqueous solution it was found that compound C formed a more stable complex with Cu(II) than did compound Cl, and it was concluded that differences in configuration and solvation properties of the free ligands 

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