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A series of studies has been undertaken to facilitate the identification and development of chiral lanthanide complexes that are able to report on changes in their local environment through modulation of the circular polarization of their emission. Reports of such systems remain relatively rare in the literature, notwithstanding the prevalence and importance of chirality in biological systems. The work described herein is separated into five chapters, the first of which comprises a discussion of relevant background information, along with a comprehensive review of responsive lanthanide-based CPL probes reported to date. A classification of these probes is built up, which informs the content of the following three chapters. Chapter 2 describes work undertaken in the pursuit of a novel lanthanide-based system for use as a CPL probe for the detection of proteins. The synthesis of an enantiopure lanthanide complex was undertaken and characterisation of this system carried out with reference to a structurally related racemic complex. A series of comparative investigations designed to probe the relative protein binding capability of these complexes was subsequently performed, which revealed that the observation of induced CPL from racemic lanthanide systems may be brought about by a change in complex constitution. This is the first example of such an effect from a well-defined racemic lanthanide complex in solution. Chapter 3 goes on to detail studies undertaken to demonstrate the utility of this racemic lanthanide system as a probe for chiral detection. Chapter 4 describes investigations carried out in an attempt to identify new systems exhibiting chiral quenching effects in solution. Initially, two pairs of enantiomeric electron-rich quenching species were assessed for their ability to quench the emission from an enantiopure DOTA-derived lanthanide complex differentially. Subsequently, investigations were focussed on examining the quenching of emission from novel enantiopure lanthanide complexes based on a 1,4,7-triazacyclononane framework, using cobalt complexes as the quenching species. Finally, Chapter 5 contains experimental procedures for each compound synthesised, as well as general experimental procedures.

Well-defined branched polymers are fundamental in the understanding and prediction of the relationship between structure and properties. This work focused on two different types of branched polymers which we described in terms of their synthesis and characterisation. In particular we carried out a study on Hyperblocks and asymmetric three-arm stars. The combination of living anionic polymerisation and “macromonomer” approach was successfully used for the production of both types of branched polymers demonstrating the great versatility of this synthetic methodology. HyperBlocks were constructed from well-defined AB2 macromonomers of polystyrene-polyisoprene-polystyrene while asymmetric three-arm stars involved the synthesis of well-defined polystyrene arms with different chain-end functionalities for the ‘long’ and the ‘short’ arm respectively. We have explored Williamson coupling reaction and copper (I)-catalysed azide-alkyne ‘click’ reaction for the final assembly of both HyperBlocks and three-arm stars. These materials were characterised by differential scanning calorimetry (DSC), transmission electron microscopy (TEM), mechanical tensile testing and temperature gradient interaction chromatography (TGIC). The characterisations in terms of morphology, thermal and mechanical properties carried out on HyperBlocks, macromonomers and the commercial thermoplastic elastomer (TPE) KratonTM D-1160 are here described and compared. Microphase separation with no long-range order was observed in the case of HyperBlocks and blends of the latter with the commercial TPE, suggesting that the highly branched structure frustrates and inhibit the formation of long-range order morphologies. Nevertheless the mechanical properties of HyperBlocks demonstrated to be superior to the properties of their well-defined linear precursors with long-range order morphologies. Analysis of the three-arm stars using the TGIC showed structural dispersity The ability of TGIC technique to separate polymers in terms of molecular weights allowed us to fully characterise the star polymers and quantify the impurities left after purification by fractionation.

This project concerns the synthesis and characterization of linear conjugated compounds, and assessment of their electrical performance. To that end, several oligo(phenylene-ethynylene)s (OPEs) were prepared and the available synthetic procedures reviewed and optimized. Monolayers of these compounds were transferred onto solid substrates by means of the Langmuir-Blodgett technique, and their physical and electrical properties evaluated by Atomic Force Microscopy (AFM) and Scanning Tunnelling Microscopy (STM). Two novel approaches to the formation of the top electrode on sandwich like metal|molecule|metal devices, based on the in-situ decomposition of gold complexes, are detailed. The synthetic methodologies appropriate for the preparation of gold ethynyl complexes Au(C≡CR)(L) (R = aryl, L= PPh3 and CNR) that are critical to the thermal and photochemical decomposition protocol are described. A convenient synthesis of bis(ethynyl) complexes trans-Ru(CCR)2(dppe)2 and unsymmetrically substituted derivatives trans-Ru(CCR1)(CCR2)(dppe)2 is described. A detailed structural and spectroelectrochemical study of the complexes, supported by TD-DFT calculations, demonstrated the relationships between the underlying electronic transitions that are responsible for the NIR absorption band shape and the relative orientations of the metal fragment and arylethynyl moieties in the oxidized species. Single molecule STM conductance studies were performed on a series of OPE and polyyne derivatives devoting special attention to the role of the molecular linker in the overall performance of the molecular junction. In that regard, a novel molecular linker CCSiMe3 was introduced and its electrical and mechanical properties benchmarked against literature known molecular anchoring groups i.e. NH2 and SH. Transistor-like behaviour was observed in preliminary electrochemical STM studies performed on complex Ru(CCC6H4CCSiMe3)2(dppe)2. Finally, the statistical treatment of the conductance (STM) and force (AFM) measurements and the Visual Basic (VBA) codes designed to analyse the large datasets collected are included.

Cavity enhanced laser induced fluorescence (CELIF) is the first technique to combine cavity ring-down (CRDS) and laser induced fluorescence (LIF) spectroscopies in a single beam experiment. It has been shown previously to extend the dynamic range of CRDS to cover six orders of magnitude in total when observing BPEB concentrations seeded in a pulsed molecular beam. This study has extended CELIF to the most general application where a fluorescer or scatterer fills the length of a pulsed CRD experiment. Under these conditions CELIF is found to produce consistently smaller errors than CRD and is competitive with it but does not extend the dynamic range. Observing acetone fluorescence and nitrogen Rayleigh scattering it has been shown how the CRD signal normalises the LIF signal generated and that the normalisation remains linear during changes to the input powers, pressures and detector gains. Furthermore it has been shown it can be used to measure absolute quantum yields of fluorescence using acetone as an example. A peltier based set-up for cooling the upper surface of a prism for the growth of thin ice films at temperatures of the troposphere and stratosphere has been constructed. A full temperature range of 225-303K was displayed. Testing showed the optimal conditions of ice growth to be a rapid expansion directed at the surface. Ice films 2.5-11.8um thick have been successfully grown at 225.2+-0.2K covering, at maximum, 96% of a 1cm by 3cm stainless steel prism surface. During growth a strong migration over time to an area 0.028+-0.002cm^2 was seen caused by a temperature gradient on the surface, dT~5K from the centre to the outside of the surface along its short side. To monitor this and ice growth, two methods have been successfully installed and tested. A morphological analysis combined with video monitoring can accurately determine areas within 5% and a HeNe laser reflected from the ice is able to monitor surface thicknesses from interference patterns. Together these offer a complete method to characterise an ice film over the duration of an experiment.

This thesis describes the asymmetric synthesis of γ-amino alcohols through the asymmetric copper-catalysed β-boration of α,β-unsaturated imines. An introduction is given into the area of β-boration/borylation (or boron conjugate addition, BCA) of electron-deficient alkenes, which forms the basis of the literature review within this thesis. The β-boration of α,β-unsaturated imines (formed in situ to circumvent problems with isolation) has been studied and the intermediate β-boryl imines have been transformed to γ-amino alcohols in one-pot (‘one-pot methodology’). An interesting side reaction was observed when methanol was present during the final oxidation step of the methodology. Indeed, evidence suggests that slight methanol oxidation gives rise to the formation of 1,3-oxazines (which can be made readily from γ-amino alcohols and aqueous formaldehyde) during this late stage oxidative step. Additional in situ IR spectroscopy (ReactIR), 1H NMR and DFT studies were performed to understand the factors which govern direct addition-elimination vs. conjugate addition of primary amines to enones and enals, with the aim of using this information to prepare α,β-unsaturated imines in situ. It was found that most enones and enals have a kinetic preference towards the direct addition of primary amines, but enones such as methyl vinyl ketone show that the kinetic preference is towards conjugate addition. DFT calculations support this observation by showing that there is a conformational effect which favours direct- over conjugate-addition, i.e. enones and enals that adopt the s-trans conformation show a lower energy barrier of addition (kinetic preference) via the direct addition pathway with primary amines. Conversely, enones and enals that adopt the s-cis conformation show a lower energy barrier of addition (kinetic preference) via the conjugate addition pathway with primary amines. A base-free (alkoxide) β-boration methodology was developed, which allows enones to be transformed to γ-amino alcohol by the addition of a primary amine, Cu2O, BINAP ligand, B2pin2 and MeOH to the starting enone, with subsequent reductive and oxidative transformations. Evidence suggests that the reaction proceeds via the α,β-unsaturated imine (formed in situ) and, in addition, the absence of the alkoxide base reduces the possibility of any alternative β-boration pathways (e.g. organocatalytic), leading to the highly enantioselective protocol (up to 99% e.e.). Enals are prone to direct borylation under the standard β-boration-type methodology and low e.e. values. It is shown herein that the use of a sterically bulky N-benzyl imine auxiliary can be used (formed from the reaction between an enal and benzhydrylamine) to favour selective β-boration and, indeed, high e.e. can be obtained using a relatively cheap and stable DM-BINAP ligand-copper catalyst system (up to 97% e.e.). The optimised one-pot methodology was applied towards the total synthesis of (R)-Fluoxetine in 45% yield (96% e.e.) and (S)-Duloxetine in 47% yield (94% e.e.), whereby the intermediate β-boryl N-benzhydryl imine can be readily exchanged by methylamine addition to form the appropriate N-methyl precursor.