| This thesis deals with the synthesis of [2]pseudorotaxane, [2]-, and [3]rotaxane architectures utilizing bis(pyridinium)ethane dications and 24-membered crown ethers as templating agents.; Eight bis(pyridinium)ethane dications 2a--h were synthesized and their complexation behaviour with six 24C8 derivatives 3a--f was examined. All the dications formed [2]pseudorotaxane geometries in solution with the crown ethers except for 2c which did not form a complex with any of 3a--f due to steric: constraints. Association constants for pseudorotaxane formation were determined by 1H NMR spectroscopy for all the complexes formed and the thermodynamics of formation of the pseudorotaxanes involving 2g and 3a--f . The crystal structures of [2]pseudorotaxanes 2e:3c, 2f:3c, and 2g:3c were determined.; [2]Pseudorotaxane 2e:3c was converted to [2]rotaxanes 7 and 9 by two different synthetic routes. The 1H NMR spectra were examined and the crystal structures of 7 and 9 were determined.; Two axle-shaped tetracations 11 and 12 were synthesized and converted, via benzylation in the presence of 3c, to the respective [3]rotaxanes 14 and 15, and [2]rotaxane molecular shuttles 16 and 17. The 1H NMR spectra of these compounds was examined and compared to the non-mechanically bonded benzylated, products 18 and 19. The dynamic behaviour of the [2]rotaxane shuttles was investigated by 1H NMR spectroscopy to determine the free energy of activation. In addition, it was established that molecular shuttle 17 displayed preference for one translational isomer. The crystal structures of 14 and 17 were also determined. |
