Reaction of imidazolium-linked ortho-cyclophanes with nickel(II) and palladium(II) salts in the presence of acetate base led to the formation of complexes where a metal centre is bound by a pair of heterocyclic carbenes which themselves are part of a cyclophane skeleton. These cyclophane–metal complexes have been characterised by NMR spectroscopy and (for five complexes) X-ray diffraction studies. The complexes are highly active as promoters of Heck and Suzuki couplings, with preliminary studies showing Heck reactions with turnover numbers approaching 10⁷. p

The crystal structure of a cyanine dye rotaxane shows that the cyclodextrin is tightly threaded round the polymethine bridge of the dye; encapsulation dramatically increases the kinetic chemical stability of the radicals formed on oxidation and reduction of the dye, making it possible to observe the rotaxane radical dication by ESR and UV-vis-NIR spectroscopy.