Carbon-based thin films are a vast group of materials of great technological importance. Thanks to the different bonding options for carbon, a large variety of structures (from amorphous to nanostructured) can be achieved in the process of film synthesis. The structural diversity increases even more if carbon is combined with relatively small quantities of atoms of other elements. This results in a set of materials with many different interesting properties for a wide range of technological applications. This doctoral thesis is about nanostructured carbon-based thin films. In particular, the focus is set on theoretical modeling, prediction of structural features and design of sulfo carbide (CSx) and carbon fluoride (CFx) thin films. The theoretical approach follows the synthetic growth concept (SGC) which is based on the density functional theory. The SGC departure point is the fact that the nanostructured films of interest can be modeled as assemblies of low dimensional units (e.g., finite graphene-like model systems), similarly to modeling graphite as stacks of graphene sheets. Moreover, the SGC includes a description of the groups of atoms that act as building blocks (i.e., precursors) during film deposition, as well as their interaction with the growing film. This thesis consists of two main parts: Prediction: In this work, I show that nanostructured CSx thin films can be expected for sulfur contents up to 20 atomic % with structural characteristics that go from graphite-like to fullerene-like (FL). In the case of CFx thin films, a diversity of structures are predicted depending on the fluorine concentration. Short range ordered structures, such as FL structure, can be expected for low concentrations (up to 5 atomic %). For increasing fluorine concentration, diamond-like and polymeric structures should predominate. As a special case, I also studied the ternary system CSxFy. The calculations show that CSxFy thin films with nanostructured features should be possible to synthesize at low sulfur and fluorine concentrations and the structural characteristics can be described and explained in terms of the binaries CSx and CFx. Design: The carbon-based thin films predicted in this thesis were synthesized by magnetron sputtering. The results from my calculations regarding structure and composition, and analysis of precursors (availability and role during deposition process) were successfully combined with the experimental techniques in the quest of obtaining films with desired structural features and understanding their properties.

Entanglement is one of the most technologically important quantum phenomena and its con-trolled creation brings us a step closer to the realisation of a quantum computer. Hybrid electron and nuclear spin systems which combine long nuclear decoherence times with the high polarisation and rapid processing times of electron spins are considered reliable candidates for the representation of the fundamental building block of a quantum computer, the qubit. In the literature electron spins quite often play the role of a mediator which can access, manipulate and couple states with long coherence times, beneficial for storing quantum information. Despite the fact that an electron spin can be a useful resource for nuclear spin systems, its permanent presence can be a source of decoherence. The use of transient photoexcited electron spins provide an additional advantage and once the operations which involve the electron spin are completed, the electron spin can decay and not interfere further with the evolution of the system. In this thesis we report magnetic resonance experiments and density functional theory calculations for the demonstration of nuclear - nuclear entanglement using photoexcited triplet states. We study homonuclear and heteronuclear fullerene derivatives and we identify in each case the relevant parameters that can lead to high fidelity entangling operations. The hyperfine interaction in a homonuclear system is the key parameter which determines the degree of entanglement between the nucelar spins according to a recent theoretical proposal. We measure and calculate the hyperfine interaction in homonuclear systems with ¹³C nuclear spins in order to prove the feasibility of this scheme. Further experiments on a fullerene system with two nuclear spins a ³¹P and a ¹H show that entangling operations of high fidelity which involve the demonstration of CNOT gates, are possible within the lifetime of the triplet state.

Thesis advisor: Lawrence T. Scott / The purpose of this project was to make progress toward a chemical synthesis of a conductive [5,5] single-walled nanotube (SWNT), specifically a C50H10 geodesic cap. The term geodesic cap refers to the smallest fragment of a nanotube that resembles the chirality and structure of a specific nanotube. Beyond synthesizing a specific nanotube, we were also interested in exploring new reactions and compounds to perform indenoannulation reactions. The interest in these compounds, which contain indeno structures, comes from their resemblance to C60 and higher fullerenes, and more specifically the intermediates to our target molecule, the C50H10 geodesic cap. / Thesis (BS) — Boston College, 2006. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Chemistry. / Discipline: College Honors Program.

This research involved the synthesis and characterisation of a range of optically active polyhedral oligomeric silsesquioxane (POSS) compounds. POSS precursor compounds containing functional groups required for subsequent attachment of the desired functional groups have been synthesised. Examples of such precursor compounds include mono-functionalised POSS compounds with periphery aldehyde, azide, amino and pyridyl functional groups. A variety of POSS compounds, functionalised with a range of optical functionalities, including optical limiters such as fulleropyrrolidine and iminofullerene, and dyes and pigments, including naphthalene, biphenyl, perylene, pyrene and porphyrin have been synthesised. The reaction of mono-functionalised POSS aldehydes with fullerene (C60) in the presence of N-methylglycine yielded the desired POSS fulleropyrrolidines, whilst reaction of mono-functionalised POSS azide with C60 yielded POSS iminofullerenes. All POSS fullerene compounds were characterised by power limiting measurements, exhibiting comparable power limiting to that of parent C60. The microwave condensation of mono-amino POSS with a range of mono- and bis-anhydrides yielded the POSS imide compounds, which were characterised by UV-Vis and fluorescence spectrophotometry. The perylene POSS imide derivative was further characterised by single crystal x-ray crystallography. The naphtha and biphenyl POSS imides exhibited extremely weak fluorescence, whilst the perylene ii POSS imide displayed particularly strong fluorescence, with a quantum yield approaching unity. The incorporation of a pyridyl group on the periphery of a mono-functionalised POSS cage allowed for the synthesis of the first porphyrin functionalised POSS compound. Mono-porphyrin POSS exhibited comparable absorption properties to other pyridyl ligated ruthenium porphyrins. Mono-functionalised pyrene POSS compounds were prepared through the reaction of 1-pyrene acid chloride with mono(3-aminopropyl)POSS. This synthetic pathway offered a convenient route to mono-functionalised pyrene POSS, in preference to the multi-substitution associated with Heck coupling. Mono-pyrene POSS was determined to be strongly fluorescent, exhibiting a high quantum yield of fluorescence

Le but de ma thèse a été de réaliser de nouveaux composés hybrides constitués de nanotubes de carbone (ou fullerènes) et de nanotubes de peptide. L'approche choisie a consisté à greffer sur des nanotubes de carbone, ou dans un premier temps sur des fullerènes, via des bras espaceurs, des cyclopeptides « de type Ghadiri» conduisant aux nanotubes de peptide. Pour se faire, la synthèse de bras espaceurs a été nécessaire ainsi que leur fixation sur les nanotubes de carbones ou fullerènes. Les cyclopeptides sont constitués d'un nombre pair d'acides aminés (8) alternés D et L s'auto-assemblant en feuillets ß antiparallèles pour conduire à des nanotubes. Des essais de solubilisation du cyclopeptide diacide révèlent l'impossibilité d'utiliser ces composés en synthèse organique, dans la mesure ou ils ne sont pas solubles dans les solvants organiques classiques. Il a fallut ainsi revoir la synthèse en incluant soit le fullerène en cours de synthèse peptidique soit en modifiant les conditions pour permettre une solubilisation du peptide. Les composés synthétisés ont été caractérisés par différentes méthodes notamment en TEM, FT-IR, ATR, microscopie optique, diffusion de la lumière. De nouvelles applications aux peptides de Ghadiri ont été cherchées en imagerie (par encapsulation du Xénon hyperpolarisé dans les cavités). Il a été mis en évidence de nouvelles organisations cristallines des peptides possibles dans des conditions contrôlées à l'aide de contre ions tels que les éléments de la première colonne du tableau périodique (Li, Na, K, Rb, ou Cs). Ces organisations, différentes en fonction du contre ion choisi, ont un caractère fractal remarquable, une organisation cristalline régulière et on observe un réseau de liaisons hydrogène inattendu dans les conditions utilisés.

The emergence of organic semiconductors is exciting since it promises to open up for straightforward and low-cost fabrication of a wide range of efficient and novel electronic devices. However, in order for this promise to become reality it is critical that new and functional fabrication techniques are developed. This thesis demonstrates the conceptualization, development, realization and implementation of a particularly straightforward and scalable fabrication process: the photo-induced and resist-free imprint patterning technique.Initial experiments revealed that some members of a group of carbon-cage molecular semiconductors – termed fullerenes – can be photochemically modified into dimeric or polymeric structures during exposure to laser light, and, importantly, that the exposed fullerene material retains its good electron-transport property while its solubility in common organic solvents is drastically lowered. With this information at hand, it was possible to design and create well-defined patterns in a solution-deposited fullerene film by exposing selected film areas to laser light and then developing the entire film in a tuned developer solution. An electronically active fullerene pattern emerges at the locations defined by the incident laser beam, and the patterning technique was successfully utilized for the fabrication of arrays of efficient field-effect transistors.In a later stage, the capacity of the photo-induced and resist-free imprint technique was demonstrated to encompass the fabrication of ubiquitous and useful CMOS circuits. These are based on a combination of p-type and n-type transistors, and a blend between a p-type organic semiconductor and an n-type fullerene compound was designed so that the latter dominated. By solution-depositing the blend film on an array of transistor structures, exposing selected transistors to laser light, and then developing the entire transistor array in a developer solution, it was possible to establish a desired combination of (non-exposed) p-type transistors and (exposed) n-type transistors. We finally utilized this combination of transistors for the fabrication of a CMOS circuit in the form of well a-functional organic inverter stage.

Water-soluble fullerene containing polymers comprising of poly(2-(dimethylamino) ethyl methacrylate)-fullerene (PDMAEMA-C60) with targeting moieties, poly(oligo(ethylene glycol) methyl ether methacrylate)-C60 (POEGMA-C60), nanocrystalline cellulose-fullerene (NCC-C60) and NCC-C60-POEGMA were synthesized and their solution properties were investigated. PDMAEMA-C60 with galactose targeting moiety was prepared by atom transfer radical polymerization (ATRP) and atom transfer radical addition (ATRA) processes. The self-assembly of galactose functionalized PDMAEMA-C60 structure in aqueous solutions was investigated using dynamic light scattering (DLS) at different pHs. A smaller hydrodynamic radius (Rh) was observed at pH 10 than at pH 3 due to electrostatic repulsion at low pH values. In addition, free PDMAEMA chains induced the demicellization of self-assembled nanostructures caused by the formation of charge transfer complex between PDMAEMA and C60. A well-defined poly(di(ethylene glycol) methyl ether methacrylate–stat-oligo(ethylene glycol) methyl ether methacrylate)-block-poly(di(ethylene glycol) methyl ether methacrylate ((PMEO2MA-stat-POEGMA300)-b-PMEO2) was successfully synthesized at room temperature via a two-step ATRP process. The block copolymer exhibited two thermal transitions at ~ 30 and 45 oC, which was believed to be associated with the formation of micelles and larger aggregates. The Rh of the aggregates increased from 47 to 90 nm, the aggregation number increased from 76 to ~9800 and Rg/Rh increased from 0.75 to 1.2 within the temperature range of 34 to 45oC. Well-defined statistical (PMEO2MA-stat-POEGMA300)-C60 was synthesized via ATRP and ATRA. The lower critical solution temperature (LCST) of (PMEO2MA-stat-POEGMA300)-C60 increased with methanol content in water, exhibiting lower LCSTs than PMEO2MA-stat-POEGMA300 for all methanol/water compositions. Higher critical micelle concentration (CMC) and larger spherical micelles were observed for (PMEO2MA-stat-POEGMA300)-C60 with increasing methanol content. The Rh of the micelles remained constant at temperature below the LCST and increased dramatically at temperature greater than the LCST, and (Rg/Rh) increased from ~ 0.75 to ~ 1.0. Nanocrystalline cellulose (NCC) was modified with water-soluble C60-(β-cyclodextrin) and (PMEO2MA-stat-POEGMA300)-C60) through a radical coupling reaction. NCC-C60-(PMEO2MA-stat-POEGMA300) possessed thermal responsive behavior in water and ~3.5 oC hysteresis associated with the heating/cooling cycles. No observable damage to NCC occurred during the radical coupling reaction as determined by TEM. NCC-C60-(β-cyclodextrin) possessed a similar thermal degradation behavior as NCC except it possessed a broader temperature range. Both NCC-fullerene systems demonstrated a radical scavenging activity when screened with the 2,2-diphenyl-1-picrylhydrazyl (DPPH). In addition, the drug loading and delivery using PDMAEMA-C60 with targeting moieties was explored. Two model drugs, namely fluorescein and pyrene were employed to evaluate the location of drug in the self-assembled structure of PDMAEMA-C60. It was found that the hydrophobic drugs were partitioned between the PDMAEMA shells and the hydrophobic fullerene cores. The drug delivery profiles indicated that PDMAEMA-C60 is an efficient drug carrier, however, it was cytotoxic to cells. The gene transfection efficacy of PDMAEMA-C60 to different cell lines was investigated and the results demonstrated that PDMAEMA-C60 exhibited good gene transfection performance. However, the targeting selectivity to liver cells cannot be determined in both cases. This study demonstrates that nanostructures of stimuli-responsive fullerene polymers can be controlled and manipulated by changing the external environments. Several potential applications, such as in drug and gene delivery, and free radical scavenging can be further explored.

De nouveaux dérivés fonctionnels du fullerène C60 ont été synthétisés à partir du dianion C602- selon la méthodologie mise au point au Laboratoire :- des dihydrofullerènes C60(CH2CO2R)2 (R = Me, Et). Des cellules photovoltaïques à base de ces dérivés et de MEH-PPV en réseaux interpénétrés montrent de bonnes performances, assez proches de celles obtenues lorsque l'accepteur est le PCBM ;- des dihydrofullerènes fonctionnels dissymétriques C60RR'. Les synthèses correspondantes reposent sur l'exploitation, jusqu'alors non réalisée dans ce but, du mécanisme réactionnel (Kadish-Fukuzumi) de la réaction entre C602- et divers dérivés halogénés ;- un fullerène diol, issu de dérivés du pentaérythritol. Les bons rendements obtenus pour cette synthèse font de ce fullerène diol un nouveau synthon de choix en chimie du fullerène C60.A partir de ce fullerène diol, de nouvelles dyades et triades ont été obtenues, l'entité électro-donneur étant le motif tétrathiafulvalène ou l'anion perchlorotriphénylméthyle. Les propriétés physico-chimiques de ces assemblages covalents donneur-accepteur ont été étudiées (spectroscopies UV-Vis, fluorescence, RPE ; électrochimie ; photophysique). / New functionalized [60]fullerene derivatives have been synthesized starting from C602- anion, following the procedure previously developed in our Laboratory :- dihydrofullerenes C60(CH2CO2R)2 (R = Me, Et). Solar cells have been built using a mixture of these compounds and MEH-PPV in interpenetrating network and they exhibit good photovoltaic characteristics, which are close to those obtained when the acceptor is PCBM ;- functionalized dissymmetric dihydrofullerenes C60RR'. The corresponding syntheses lie upon a new interpretation of the Kadish-Fukuzumi mechanism, so far unexplored in this way, associated with the reaction between C602- and various halogeno derivatives ;- a fullerene diol, issued from pentaerythritol derivatives. Thanks to good yields observed in this synthesis, this fullerene diol appears to be a new promising building block in fullerene chemistry.Starting from the latter diol, new C60-based dyads and triads have been obtained, the electron donor moiety being the tetrathiafulvalene core or the perchlorotriphenylmethyl anion. The physico-chemical properties of these donor-acceptor covalent assemblies have been studied (UV-Vis, fluorescence, ESR spectroscopic methods ; electrochemistry ; photophysics).

none

Reactions of Fullerene with Tris(diphenylacetylene)(carbonyl)Tungsten and structure identified of these compounds. Due to its have many special mechanism for Tris(diphenylacetylene)(carbonyl)Tungsten. They could form interested structure of new compounds. Synthesis in high temperature we could get metallofullerene compounds W(CO)(£b2-C60)(£b2-PhC¡ÝCPh)(£b4-C4Ph4) 1a and W(CO)(£b2-C60)(¡ÝCPh)(£b5-C5Ph5) 1b. We also through C-H activation to get compound W(CO)2(£b3,£b5-C5Ph4(o-C6H4)CHPh) 2. To separate and Purify these compounds. To make sure mechanism of compound 2, we use cross experiment to confirm it.