Anion-templated assembly of rotaxanes
Anion templation is used to develop a general method for rotaxane synthesis. The anion-templated synthesis of three new rotaxanes containing positively charged pyridinium axles and neutral isophthalamide macrocyclic components is described. The incorporation of electron withdrawing substituents, such as the nitro group, into the 5-position of an isophthalamide bis-vinyl acyclic precursor results in a significant improvement in rotaxane assembly yields. Rotaxane anion binding strengths are also enhanced whilst the rotaxane's unique interlocked binding domain ensures selectivity for chloride – the templating anion – is maintained.