Dancing with interlocked molecules: The generation of molecular motion for drug delivery applications and harnessing molecular recognition to create and manipulate exotic structures

This Thesis will begin by presenting a brief historical introduction (Chapter 1) of the emergence on the scene of mechanically interlocked molecules (MIMs) and the different kinds of MIMs that exist today. It will then move on to explore a select variety of molecular motions that I have worked on during my sojourn in the Stoddart group.;The first system (Chapter 2) under discussion will induce a polymer backbone to change reversibly from rigid to coiled and vice-versa using various generations of Frechet-type dendrons. This type of system has the potential to attach linear conjugated polymer chains into molecular circuits in order to devise a network of molecular wires in a predictable fashion.;The story then changes (Chapter 3) to describe a novel procedure which was developed to be able to create higher order interlocked structures by exploiting the thermodynamic landscape of the individual molecular components relative to the mechanically interlocked products.;The following chapter (Chapter 4) describes our successful attempt in using mesoporous silica nanoparticles that have been decorated with pH responsive molecular switches that allow the pores to be either open or closed, depending on the environmental pH. The key aspect of this system is that it operates in water, a feature which opens up the possibility of using it in a biological drug delivery context.;The final chapter (Chapter 5) describes an analogous system which no longer relies on external stimuli - such as light or magnetic fields - or non-selective internal stimuli, such as heat or pH. This novel, breakthrough system undergoes release, based on the presence of enzymes. Human diseases are known to over-express a number of enzymes. If we can promote release to occur in the local vicinity of these abundant biological markers, we could create an unparalleled targeted drug delivery system that would have the potential to eliminate any side-effects the drugs may normally elicit.;The goal of this Thesis is to provide the reader with an insight into the world of molecular motion using MIMs and to suggest how these nanoscale motions can potentially be translated into working devices.