This dissertation is a summary of my research developing the synthesis and assembly of functional materials from nanoscale building blocks and studying their emergent properties. Chapter 1 introduces superatoms as exciting atomically precise supramolecular building blocks for materials design. Bottom-up assembly of these superatoms into materials with increased dimensionality (0D, 1D, 2D, and 3D) offers exciting opportunities to create novel solid-state compounds with tailored functions for widespread technological applications. I review recent advances to assemble superatomic materials and focus on assemblies from metal chalcogenide clusters and fullerenes. In subsequent chapters, I employ several of these nanoscale superatoms as the precursors to functional materials. Chapter 2 describes the synthesis and structural characterization of a hybrid solid-state compound assembled from two building blocks: a nickel telluride superatom and an endohedral fullerene. Although a varied library of binary superatomic solids has been assembled from fullerenes, this is the first demonstration of a superatomic assembly using an endohedral fullerene as a building block. Lu3N@C80 fullerenes are dimerized in this new solid-state compound with an unpreceded orientation of the encapsulated metal nitride cluster. I explore the structural characterization of this material supported with computational evidence to explain the dimerization and orientation of the endohedral fullerenes. In Chapter 3 I begin to detail my exploration into assembling superatoms at micro and meso-scales –which will be the focus of Chapters 3-5. Polymers offer attractive mechanical and self-assembly properties that when combined with the attractive redox, optical, and magnetic properties of molecular clusters, these materials chart new paths to developing advanced materials and technologies. Chapter 3 describes charge transfer interactions between perylene diimide and cobalt telluride superatoms that drive the assembly of a solid-state compound from these two building blocks and inspired the design of a diblock copolymer template. Chapters 4 and 5 detail the synthesis and characterization of a polymer with functionalized cobalt selenide side units. I describe a cationic homopolymer in Chapter 4 and diblock copolymer in Chapter 5 synthesized from ring opening polymerization of norbornene-derived monomers. Chapter 4 describes potential applications of the homopolymer system such as thin film fabrication. Chapter 5 discusses the self-assembly of the redox-active diblock copolymer into cross-linkable vesicle structures that can encapsulate molecular cargo. Finally, in Chapter 6 I introduce a new molecular building block to form gold metal surface bonds. Bisaminocyclopropenylidenes (BACs) are a class of carbenes that, much like N-heterocyclic carbenes, have been widely employed for catalysis but have yet to be explored for materials design. This chapter describes the structure and binding orientation of a BAC on an Au(111) surface. Each of these chapters illustrates how the synthetic flexibility of molecular building blocks enables the design of functional materials with tunable properties.

Since the discovery of the buckyball in 1985, researchers have imagined its potential in fields ranging from materials science to medicinal chemistry. The unique size, shape and hydrophobicity of C 60 fullerene endow it with the ability to interact with biological superstructures such as enzymes and membranes making it attractive as a potential pharmacophore. In this regard, we have developed a new, simple route to water soluble fullerene amino acids, both alkyl and aryl, through the dipolar addition of azido starting materials. The synthesis of our phenylalanine derivative, including the chromatographic purification, requires only one day for its completion. We have subsequently used our C 60 phenylalanine derivative in the synthesis of a series of C 60 peptides for the purposes of enzyme inhibition, specifically human immunodeficiency virus Type 1 protease, a critical viral enzyme responsible for the maturation of the virus and a popular target of medicinal chemists. We have demonstrated the ability of our C 60 amino acids and peptides to inhibit HIV-1 PR in a cell-free fluorescence based assay at low nanomolar concentrations. Graphite, or specifically graphene, has recently come to the forefront of nanomaterials research due to it similar scale, properties, and reaction pathways as other more costly carbon nanostructures such as carbon nanotubes. We have demonstrated the high yield functionalization of graphitic starting materials through the thermal decomposition of azido amino acids to their corresponding nitrene. The result is an inexpensive, highly functionalized, carbon based scaffold.

No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 229-236). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 229-236). Also available on the Internet.

Commercial production and use of carbon-based nanomaterials will inevitably lead to the release of nanoscale compounds into to the environment. While fullerene nanoparticles, such as nC60 and multi-wall nanotubes (MWNTs), exhibit toxicity to certain microbes and human cell lines, their transport and deposition in subsurface environments are largely unknown. In this study, nanoparticle transport experiments were conducted in one-dimensional columns packed with water-saturated glass beads, quartz sands, or natural soil. Results demonstrated that nC60 transport was strongly influenced by electrolyte species and concentration, as well as mean grain size and flow rate. The attachment of nC60 was largely irreversible, with introduction of pH 12 water required to detach substantial quantities of retained nC60. Measured nC60 breakthrough curves and retention profiles in quartz sands suggest that the retention of nC60 was primarily due to attachment in a first energy minimum and that clean-bed filtration theory alone was not sufficient to describe the experimental data. In the presence of stabilizing agents, including surfactant, fulvic and humic acids, significant enhancement of nC60 transport in quartz sands was observed. In two natural soils, Appling and Webster soil, complete retention of nC60 was observed, even after introducing up to 65 pore volumes of nC60 suspension. However, nC60 readily transported through Appling soil in the presence of surfactant. For MWNTs with a manufacture-reported (MR) length of 50 μm readily transported through sand columns and the retention of MWNTs at higher input concentrations increased with the MR length. The data also suggested MWNTs exhibited higher mobility in quartz sands than nC60 or single-wall nanotubes under similar chemical conditions. These findings advance our current understanding of fundamental processes governing nanoparticle transport and retention in porous media and provide reliable experimental data for the development of nanoparticle transport models.

Thesis (Ph.D.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2009/06/11). Includes bibliographical references.

Neste trabalho, propomos o uso do átomo do silício da molécula C59Si como uma maneira possível de ancorar moléculas de fulerenos em uma superfície de silício, devido à formação de uma ligação forte com um dos átomos de silício da superfície. Consideramos uma superfície Si(100) monohidrogenada com um H removido de um dos átomos de silício da superfície e neste local uma molécula de C59Si é adsorvida. Através de cálculos ab initio baseados na Teoria do Funcional da Densidade, obtivemos uma distância de ligação de 2,37 Å e uma energia de ligação de aproximadamente 2,10 eV. Diferentes possíveis rotas para obter a adsorção dessa molécula são discutidas. Em particular, propomos que uma possível rota seria através da molécula, ainda não detectada, (C59Si)2. A partir de cálculos ab initio mostramos que as duas moléculas de C59Si ((C59Si)2) estão ligadas através de seus átomos de silício. Obtivemos uma distância final de ligação de 2,36 Å e uma energia de ligação com respeito à dissociação em dois monômeros C59Si de 1,6 eV. Uma análise da estrutura eletrônica e do espectro vibracional da molécula (C59Si)2 é apresentada e comparada com o monômero C59Si. Investigamos também a ligação do fulereno C60N com a superfície de silício através do átomo de nitrogênio, assim como a adsorção do fulereno endoédrico N@C59Si na superfície Si(100):H. Finalmente, investigamos a interação da molécula de C59Si com uma superfície de Au(111) mediada por um átomo do enxôfre. / In this work we propose the use of the Si atom in the C59Si molecule as a possible way to controllably anchor fullerene molecules on a Si surface, due to the formation of a strong bond to one of the Si surface atoms. We consider a monohydride Si(100) surface with a H removed from one of the Si surface atoms and the C59Si adsorbed at this site. Through ab initio calculations based on Density Functional Theory, we obtained a final Si_super-Si_C59Si bond distance of 2.37 Å, and a binding energy of approximately 2.1 eV. Different possible routes to obtain the adsorption of such a molecule will be discussed. In particular, we propose that a as yet undetected (C59Si)2 molecule could be used for such a reaction. Through ab initio calculations we show that the two C59Si molecules will be bonded via their Si atoms, forming a dumbbell-like structure. We obtain a final Si-Si bond distance of 2.36 Å, and a binding energy with respect to dissociation into two C59Si monomers of 1.6 eV. An analysis of the (C59Si)2 electronic structure and vibrational spectra will be presented and compared with the C59Si monomer. We also investigate the binding of the C60} fullerene on the Si surface via nitrogen atoms, as well as the endohedral fullerene N@C59Si at the Si(100) surface. Finally, we also investigate the interaction of the C59Si molecule with Au(111) surface via sulfur atoms.

This thesis contains the results of molecular dynamics simulations of molecule-surface interactions, looking particularly at fullerene molecules and carbon surfaces. Energetic impacts of fullerene molecules on graphite create defect craters. The relationship between the parameters of the impacting molecule and the parameters of the crater are examined and found to be a function of the energy and velocity of the impacting molecule. Less energetic fullerene molecules can be scattered from a graphite surface and the partitioning of energy after a scattering event is investigated. It is found that a large fraction of the kinetic energy retained after impact is translational energy, with a small fraction of rotational energy and a number of vibrational modes. At impact energies where the surface is not broken and at normal incidence, surface waves are seen to occur. These waves are used to develop a method of desorbing molecules from a graphite surface without damage to either the surface or the molecules being desorbed. A number of fullerene molecules are investigated and ways to increase the desorption yield are examined. It is found that this is a successful technique for desorbing large numbers of intact molecules from graphite. This technique could be used for desorbing intact molecules into a gas phase for mass spectrometric analysis.

The work described in this thesis concerns development, synthesis and characterisation of new molecular compounds and materials based on the carbon allotropes fullerene (C60) and graphene. A stepwise strategy to a symmetric ferrocene-linked dumbbell of fulleropyrrolidines was developed. The versatility of this approach was demonstrated in the synthesis of a non-symmetric fulleropyrrolidine-ferrocene-tryptophan triad. A new tethered bis-aldehyde, capable of regiospecific bis-pyrrolidination of a C60-fullerene in predominantly trans fashion, was designed, synthesised and reacted with glycine and C60 to yield the desired N-unfunctionalised bis(pyrrolidine)fullerene. A catenane dimer composed of two bis(pyrrolidine)fullerenes was obtained as a minor co-product. From the synthesis of the N-methyl analogue, the catenane dimer could be separated from the monomeric main product and fully characterised by NMR spectroscopy. Working towards organometallic fullerene-based molecular wires, the N-unfunctionalised bis(pyrrolidine)fullerene was coupled to an activated carboxyferrocene-fullerene fragment by amide links to yield a ferrocene-linked fullerene trimer, as indicated by mass spectrometry from reactions carried out at small scale A small library of conjugated diarylacetylene linkers, to be coupled to C60 via metal-mediated hydroarylation, was developed. Selected linker precursors were prepared and characterised, and the hydroarylation has been adapted using simple arylboronic acids. Few-layer graphene was prepared and dip-deposited from suspension onto a piezoelectric polymer substrate. Spontaneous side-selective deposition was observed and, from the perspective of non-covalent interaction, rationalised as being driven by the inbuilt polarization of the polymer. Aiming for selectively edge-oxidized graphene, a number of graphitic materials were treated with a combination of ozone and hydrogen peroxide under sonication. This mild, metal-free procedure led to edge-oxidation and exfoliation with very simple isolation of clean materials indicated by microscopy, spectroscopy, and thermogravimetric analysis.