Novel Synthetic Molecular Machines

Abstract

Molecular pumps in biology are responsible for the generation of chemical gradients across membranes; a process that is required for energy storage in both cells and intracellular organelles. Inspired by their biological counterparts, to date, a number of artificial molecular pumps have been devised. A chemically fuelled information ratchet has been recently reported, that utilises the metal-free active template formation of rotaxanes to continuously pump crown-ether macrocycles from bulk solution onto a molecular axle. The project reported in this thesis aims to develop the understanding of this molecular pump by investigating the effects of changing the parameters of the system. So far, the original pump has been successfully re-synthesized and operated, reproducing the original findings. A second version of the pump, whereby the catchment area has a lower affinity for the macrocycle, was also synthesised and investigated. The autonomous operation of the second version of the pump was carried out and several studies that were conducted with the original pump, were repeated with the new pump design. From the experimental results, it was concluded that a reduced number of triazole stations in the catchment area is likely to lead to less efficient pumping and significantly faster dethreading of the interlocked species. The findings demonstrate that the quantity of non-covalent interactions between the macrocycle and the catchment area can affect the outcome of pumping. Overall, an improved understanding of this system, aids in the comprehension of biological pumps, and the development and rational design of future autonomous molecular machines.

Date of Award	1 Aug 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	David August (Supervisor) & David Leigh (Supervisor)