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The incursion of the physical sciences into the medical sphere has led to myriad investigations in the use of nanomaterials for diagnostic and therapeutic purposes. In particular, the fullerenes show great promise in a number of areas because of their unique molecular properties. The chemistry of these carbon building blocks can be harnessed through covalent functionalisation and incorporation into supramolecular architectures such as extended self-assembled structures and molecular machines based on mechanically interlocked molecules. This thesis describes the synthesis and characterisation of such supramolecular structures incorporating fullerenes, whose potential utility in nanomedicine is demonstrated. Water-solubilisation of fullerene C60 is achieved in the first part of this thesis by covalent functionalisation with triethylene glycol monoethyl ether. The resulting complex molecular structure is elucidated and a new method developed for interpreting elemental and thermal gravimetric analyses. It is highly soluble in water (37 mg/mL) and exhibits concentration-dependent photoluminescent behaviour suitable for biomedical applications. Ultraviolet-Visible absorption data points to the formation of self-assembled structures. Over time, these self-assembled structures grow considerably into hydrogels. Optical and scanning electron microscopies show the hydrogels have a tricontinuous hierarchical structure of great promise for use in drug delivery. The same functionalisation protocol is applied to higher fullerenes C70, C84 and C90–92, and extensive hierarchical structures are formed for the latter two. It is proposed that the presence of corannulene-like hydrophobic regions in the functionalised fullerenes affects the formation of hierarchical structures. Atomic force microscopy nanoindentation shows that the strongest of the formed hydrogels (C90–92 derivative, E = 432 ± 286 kPa) fares remarkably well against other supramolecular hydrogel competitors. In the second part of this thesis, fullerene C60 is functionalised for incorporation into a rotaxane-based molecular machine. Two new iodo-alkyne functionalised fullerene derivatives are isolated in this process. C60 is incorporated into a four-station [3]rotaxane with two peripheral naphthalene diimide stations and two ferrocene-functionalised macrocycles via a copper-catalysed click reaction. The anion-induced motion of the macrocycles leads to a tuneable photoluminescent response due to photoinduced electron transfer. C60 plays a crucial electron-accepting role in this setup. In this way, this fullerene-containing mechanically interlocked architecture demonstrates a unique platform for the sensing of chloride ions. The utility of this [3]rotaxane is expanded into a theranostic tool by the demonstration of tuneable singlet oxygen generation by the central fullerene moiety concomitant with the tuneable photoluminescence.

Quantum information processing (QIP), which inherently utilizes quantum mechanical phenomena to perform information processing, may outperform its classical counterpart at certain tasks. As one of the physical implementations of QIP, the electron-spin based architecture has recently attracted great interests. Endohedral fullerenes with unpaired electrons, such as N@C60, are promising candidates to embody the qubits because of their long spin decoherence time. This thesis addresses several fundamental aspects of the strategy of engineering the N@C60 molecules for applications in QIP.Chemical functionalization of N@C60 is investigated and several different derivatives of N@C60 are synthesized. These N@C60 derivatives exhibit different stability when they are exposed to ambient light in a degassed solution. The cyclopropane derivative of N@C60 shows comparable stability to pristine N@C60, whereas the pyrrolidine derivatives demonstrate much lower stability. To elucidate the effect of the functional groups on the stability, an escape mechanism of the encapsulated nitrogen atom is proposed based on DFT calculations. The escape of nitrogen is facilitated by a 6-membered ring formed in the decomposition of the pyrrolidine derivatives of N@C60. In contrast, the 4-membered ring formed in the cyclopropane derivative of N@C60 prohibits such an escape through the addends.Two N@C60-porphyrin dyads are synthesized. The dyad with free base porphyrin exhibits typical zero-field splitting (ZFS) features due to functionalization in the solid-state electron spin resonance (ESR) spectrum. However, the nitrogen ESR signal in the second dyad of N@C60 and copper porphyrin is completely suppressed at a wide range of sample concentrations. The dipolar coupling between the copper spin and the nitrogen spins is calculated to be 27.0 MHz. To prove the presence of the encapsulated nitrogen atom in the second dyad, demetallation of the copper porphyrin moiety is carried out. The recovery of approximately 82% of the signal intensity confirms that the dipolar coupling suppresses the ESR signal of N@C60.To prepare ordered structure of N@C60, the nematic matrix MBBA is employed to align the pyrrolidine derivatives of N@C60. Orientations of these derivatives are investigated through simulation of their ESR spectra. The derivatives with a –CH3 or phenyl group derived straightforward from the N-substituent of the pyrrolidine ring are preferentially oriented based on their powder-like ESR spectra in the MBBA matrix. An angle of about is also found between the directors of fullerene derivatives and MBBA. In contrast, the derivatives with a –CH₂ group inserted between the phenyl group and the pyrrolidine ring are nearly randomly distributed in MBBA. These results illustrate the applicability of liquid crystal as a matrix to align N@C60 derivatives for QIP applications.

Nanomaterials have attracted great interest due to the unique physical properties and great potential in the applications of nanoscale devices. Two dimensional atomic crystals, which are atomic thickness, especially graphene, have triggered the gold rush recently due to the fascinating high mobility at room temperature for future electronics. The crystal structure of nanomaterials will have great influence on their physical properties. Thus, this thesis is focused on developing the methods to control the crystal structure of nanomaterials, namely quantum dots as semiconductor, boron nitride (BN) as insulator, graphene as semimetal, with low cost for their applications in photonics, structural support and electronics. In this thesis, firstly, Mn doped ZnSe quantum dots have been synthesized using colloidal synthesis. The shape control of Mn doped ZnSe quantum dots has been achieved from branched to spherical by switching the injection temperature from kinetics to thermodynamics region. Injection rates have been found to have effect on controlling the crystal phase from zinc blende to wurtzite. The structural-property relationship has been investigated. It is found that the spherical wurtzite Mn doped ZnSe quantum dots have the highest quantum yield comparing with other shape or crystal phase of the dots. Then, the Mn doped ZnSe quantum dots were deposited onto the BN sheets, which were micron-sized and fabricated by chemical exfoliation, for high resolution imaging. It is the first demonstration of utilizing ultrathin carbon free 2D atomic crystal as support for high resolution imaging. Phase contrast images reveal moiré interference patterns between nanocrystals and BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes using a newly developed equation method. Double diffraction is observed and has been analyzed using a vector method. As only a few microns sized 2D atomic crystal, like BN, can be fabricated by the chemical exfoliation. Chemical vapour deposition (CVD) is as used as an alternative to fabricate large area graphene. The mechanism and growth dynamics of graphene domains have been investigated using Cu catalyzed atmospheric pressure CVD. Rectangular few layer graphene domains were synthesized for the first time. It only grows on the Cu grains with (111) orientation due to the interplay between atomic structure of Cu lattice and graphene domains. Hexagonal graphene domains can form on nearly all non-(111) Cu surfaces. The few layer hexagonal single crystal graphene domains were aligned in their crystallographic orientation over millimetre scale. In order to improve the alignment and reduce the layer of graphene domains, a novel method is invented to perform the CVD reaction above the melting point of copper (1090 ºC) and using molybdenum or tungsten to prevent the balling of the copper from dewetting. By controlling the amount of hydrogen during the growth, individual single crystal domains of monolayer over 200 µm are produced determined by electron diffraction mapping. Raman mapping shows the monolayer nature of graphene grown by this method. This graphene exhibits a linear dispersion relationship and no sign of doping. The large scale alignment of monolayer hexagonal graphene domains with epitaxial relationship on Cu is the key to get wafer-sized single crystal monolayer graphene films. This paves the way for industry scale production of 2D single crystal graphene.

Information processors that harness quantum mechanics may be able to outperform their classical counterparts at certain tasks. Quantum information processing (QIP) can utilize the quantum mechanical phenomenon of entanglement to implement quantum algorithms. Endohedral fullerenes, where atoms, ions or clusters are trapped in a carbon cage, are a class of nanomaterials that show great promise as the basis for a solid-state QIP architecture. Some endohedral fullerenes are spin–active, and offer the potential to encode information in their spin-states. This thesis addresses the challenges of how to engineer the components of a scalable QIP architecture based on endohedral fullerenes. It focuses on the synthesis and characterization of molecules which may, in the future, permit the demonstration of entanglement; the optical read-out of quantum states; and the creation of quasi-one-dimensional molecular arrays. Due to its long spin decoherence time, N@C60 is the selected as the basic molecular unit for ‘coupled’ fullerene pairs, molecular systems for which it may be possible to demonstrate entanglement. To this end, isolated fullerene pairs, in the form of spin-bearing fullerene dimers, are created. This begins with the processing of N@C60 at the macroscale and leads towards the synthesis of 15N@C60-15N@C60 dimers at the microscale. High throughput processing is introduced as the most efficient technique to obtain high purity N@C60 on a reasonable timescale. A scheme to produce symmetric and asymmetric fullerene dimers is also demonstrated. EPR spectroscopy of the dimers in the solid-state confirms derivatization, whilst permitting the modelling of spin–spin interactions for 'coupled' fullerene pairs. This suggests that the optimum inter–spin separation for which to observe spin–spin coupling in powders is circa 3 nm. Motivated by the properties of the trivalent erbium ion for the optical detection of quantum states, optically–active erbium–doped fullerenes are also investigated. These erbium metallofullerenes are synthesized and isolated as individual isomers. They are characterized by low temperature photoluminescence spectroscopy, emitting in the infra- red at a wavelength of 1.5 μm. The luminescence is markedly different where a C2 cluster is trapped alongside the erbium ions in the fullerene cage. Er2C2@C82 (isomer I) exhibits emission linewidths that are comparable to those observed for Er3+ in crystals. Finally, the discovery of a novel praseodymium-doped fullerene is reported. The balance of evidence favours the structure being assigned as Pr2@C72. This novel endohedral fullerene forms quasi-one-dimensional arrays in carbon nanotubes, which is a useful proof-of-principle of how a scaled fullerene-based architecture may be achieved.

Quantum information processing (QIP) has the potential to reduce the complexity of many classically ‘hard’ computational problems. To implement quantum information algorithms, a suitable physical quantum computer architecture must be identified. One approach is to store quantum information in the electron spins of an array of paramagnetic N@C60 endohedral fullerene molecules, using the electron-electron dipolar interaction to permit the formation of the entangled quantum states needed to implement QIP. This thesis explores two different chemical methods to create two-spin centre arrays that contain N@C60. The first method uses a double 2,3 dipolar cycloaddition reaction to a dibenzaldehyde-terminated oligo-p-phenylene polyethynylene (OPE) unit , to create an (S3/2, S3/2) N@C60-N@C60 dimer with a fixed spin centre separation of 2.7 nm. The second approach is via a self-assembly scheme in which a Lewis base functionalised N@C60 molecule coordinates to an antiferromagnetic metallic ring magnet to form a (S3/2, S3/2) two-spin centre N@C60-Cr7Ni system with an inter-spin separation of 1.4 nm. In both systems, a significant perturbation of the electron spin transition energies is observed using CW ESR, this perturbation is shown to be well accounted for by the inclusion of an electron-electron dipolar coupling term in the electron spin Hamiltonians. To create entanglement in an ensemble of two-spin centre molecules, the dipolar coupling interaction must lie within a narrow distribution. To achieve this not only the separation but also the orientation of the inter-spin axis with respect to the applied magnetic field must be controlled for which a method of macroscopic alignment is required. The potential of using a uniaxially drawn liquid crystal elastomer to exert uniaxial order on fullerene dimers is tested, finding that the degree of alignment is insufficient, possibly a result of the propensity for the fullerene molecules to phase separate from the elastomer. This phase separation is shown to restrict N@C60 phase coherence lifetime to 1.4 µs at 40 K due to instantaneous spin diffusion. The electron spin environment of both N@C60 and an N@C60-C60 dimer in a polymer matrix is examined using polystyrene as the host matrix. By deuteration of the polystyrene matrix, a maximum phase coherence lifetimes of 48 µs and 21 µs are measured for the N@C60 and N@C60-C60 dimer, respectively. The concept of reading out the electron spin state of N@C60 molecules by coupling it to a spin system that can be probed using optically detected magnetic resonance (ODMR) such as an NV- centre has been previously suggested. To this end, the photostability of N@C60 under 637 nm laser illumination has been examined in solution. The effect of the presence of an atmospheric concentration of oxygen is striking, affording a 57-fold retardation in the photodecomposition of N@C60 compared to a degassed solution. When ambient oxygen is present, the average number of excitations that are required to cause decomposition is ≈60000. Finally, for future UV photophysics experiments involving N@C60, the best solvent to use was found to be decalin, finding that it significantly slowed decomposition of N@C60 in both ambient and degassed solutions. The conclusions of this work make a significant contribution to the field of QIP with N@C60, showing that there is a bright future for N@C60.