Thesis advisor: Lawrence T. Scott / The synthesis of carbon nanotubes is of great interest to a wide variety of chemists. Our approach uses traditional organic synthesis to build rationally designed fullerene fragments, which can be grown into carbon nanotubes. Two target bowls were selected for this research; one consisting of 50 carbon atoms, and the second containing 40. Both bowls, when grown through a repetitive sequence of Diels-Alder addition and rearomatization, would result in the formation of [5,5] carbon nanotubes. The first route attempted was the synthesis of a C50H10 end-cap using diphenanthrylcorannulene as an advanced intermediate. However, after a great deal of trial and error to make the substituted diphenanthrylketone needed, the route was abandoned when the aldol condensation of this ketone with acephenanthrylquinone could not be made efficient enough to continue with the synthesis. The second synthetic target, the C40H10 end-cap, was pursued through the synthesis of corannulene, which was then substituted with bromine. The bromine atoms were converted to vinyl groups, and a Diels-Alder cycloaddition followed by rearomatization forms the new benzo substituent. This was successful for the smallest members of the benzocorannulene family; however, the yields were too low for a practical route to pentabenzo[a,d,g,j,m]corannulene from corannulene, which was the planned precursor for the ultimate formation of the target bowl. An adapted method was employed for the synthesis of larger benzologs. Tribenzo[a,d,j]corannulene was prepared through a modified version of the literature method for the synthesis of dibenzo[a,g]corannulene. With this material characterized and available in gram quantities, the synthesis of pentabenzo[a,d,g,j,m]corannulene was pursued through the dibromination of tribenzo[a,d,j]corannulene, followed by vinylation and subsequent Diels-Alder reaction to accomplish a two-fold benzannulation. This molecule was synthesized and characterized here for the first time. Tetrabenzo[a,d,g,j]corannulene was also observed in some of the reactions, but was never isolated or characterized. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: Lawrence T. Scott / Curved carbon-rich materials such as carbon nanotubes and carbon nanocones have unique mechanical strength, charge carrying ability and structure. Efficient syntheses to access these strained structures are required to obtain usable quantities of these materials in order to exploit their unique properties. This dissertation describes the recent efforts toward gaining access to these interesting structures using corannulene as the foundation for the curvature. Chapter 2 offers a microwave assisted tandem Suzuki-Heck-type coupling of <italic>peri</italic>-dichloroacenaphthene with various aryl boronic acids. This allows for the formation of strained unsaturated five-membered rings in a single transformation. The extension of this methodology to <italic>peri</italic>-chloroacenaphthylboronic acids and aryl halides was also investigated. Chapter 3 discusses efforts toward the total synthesis of a [10,10] carbon nanotube end-cap. The key step was optimized on bicorannulenyl and applied to 1,3,5,7,9-pentacorannulenylcorannulene. Preliminary Diels-Alder reactions have been successful with di-cyclopenta[<italic>def</italic>]phenanthro[3,3a,4,4a,5,6-<italic>cdefg</italic>;3',3a',4',4a',5',6'-<italic>nopqr</italic>]pentacene, suggesting that the C₁₂₀H₂₀ end-cap should also be reactive under similar conditions. Chapter 4 presents progress toward the total synthesis of a carbon nanocone with a single five-membered ring. The acid-catalyzed oxidative cyclization seems to effect a 1,2-aryl shift, preventing the desired six-membered ring cyclodehydrogenation. To render this rearrangement degenerate and thus irrelevant, 9-phenanthrylcorannulene was utilized to replace the problematic 1-naphthylcorannulene. Chapter 5 describes the collaboration between the Shenhar laboratory at The Hebrew University of Jerusalem and the Scott laboratory to form supramolecular polymers using corannulene derivatives. It had been shown that corannulene tetraanion can dimerize with lithium cations, so the limitations were probed with the following larger corannulene networks: <italic>p</italic>-dicorannulenylbenzene, 1,3,5-tricorannulenylbenzene and 1,3,5,7,9-pentacorannulenylcorannulene. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

The major part of my thesis work includes large scale production of corannulene, C20H10, a bowl-shaped Polycyclic Aromatic Hydrocarbon. Over the road towards corannulene via tetramethylfluoranthene, we improved several steps of the existing multistep procedure. These improvements include: -Nucleophilic displacement of chloride in 2,7-dimethyl-1-chloromethyl- naphthalene with cyanide gave an excellent yield of 2,7-dimethyl-1-naphthalene- acetonitrile when performed in acetonitrile instead of DMSO or acetone/water. -Oxidation of 3,8-dimethyl-1-acenaphthenone to 3,8-dimethylacenaphthaquinone was successfully achieved with HBr/DMSO instead of selenium dioxide, which usually requires tedious work up. -Overall yield of 3,8-dimethylacenaphth- aquinone was greatly improved in comparison with the previous reports. -Palladium catalyzed large scale debromination of tetrabromocorannulene was accomplished within thirty minutes of brief reflux, in contrast to the original Zn/KI method which took weeks for completion. Alternative palladium catalyzed ring closure methods where tested for synthesis of 1,6,7,10-tetramethylfluroanthene (25), a key intermediate in corannulene production. A structurally similar system, 7,10-dimethylfluoranthene was synthesized by this new approach in low yield. Unfortunately, we did not succeed in the synthesis of 25 using similar methodology, since all our attempts to produce the prerequisite 2,7-dimethyl-1-naphthylboronic acid failed. Elaboration of the corannulene core by coupling tetrabromocorannulene with p-methoxyphenylboronic acid and p-methoxycarbonylphenylboronic acid under Suzuki conditions resulted in formation of two vital intermediates which can be used to build capsules with corannulene caps.

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Transport of ions and molecules in solids is a very important process in many technological applications, for example, in drug delivery, separation processes, and in power sources such as ion diffusion in electrodes or in solid electrolytes. Progress in the understanding of the ionic and molecular transport mechanisms in solids can be used to substantially increase the performance of devices. In this dissertation we use ab initio calculations and molecular dynamics simulations to investigate the mechamisn of transport in solid. We first analyze molecular transport and storage of H2. Different lightweight carbon materials have been of great interest for H2 storage. However, pure carbon materials have low H2 storage capacity at ambient conditions and cannot satisfy current required storage capacities. Modification of carbon materials that enhance the interaction between H2 and absorbents and thus improve the physisorption of H2, is needed for hydrogen storage. In this dissertation, corannulene and alkali metal-doped corannulene are investigated as candidate materials for hydrogen storage. Molecularalso investigated. Using computational chemistry, we predict enhanced H2 adsorption on molecular systems with modification and hydrogen uptake can reach DOE target of 6.5wt% at at 294 bar at 273 K, and 309 bar at 300 K. In the second part of this dissertation, we study the lithium ion transport from a solid electrolyte phase to a solid electrode phase. Improvement of ionic transport in solid electrolytes is a key element in the development of the solid lithium ion batteries. One promising material is dilithium phthalocyanine (Li2Pc), which upon self-assembly may form conducting channels for fast ion transport. Computational chemistry is employed to investigate such phenomena: (1) to analyze the crystalline structure of Li2Pc and formation of conducting channels; (2) to understand the transport of Li ions inside channels driven by an electric field; (3) to study the continuity of the conducting channels through interface. The study shows Li2Pc has higher conductivity than PEO as electrolyte.

The study of polycyclic aromatic hydrocarbons (PAHs) with curved surfaces, also known as buckybowls or fullerene fragments, represent an area which is under intense investigation by organic chemists and material scientists. This dissertation describes research that contributes to this field. The availability of multi-gram quantities of the smallest buckybowl, corannulene, has led to the synthesis of several larger systems with buckybowl subunits. Cyclotrimerization of corannulyne using palladium(0) as the catalyst is described. The resulting product, C60H24, is a highly nonplanar hydrocarbon with very interesting conformational dynamics. The X-ray crystallography of the cyclotrimer confirms the “twist” conformation with C1 symmetry. The cyclotrimer also shows three distinct corannulene bowls with very different inversion barriers as confirmed by both experiment and calculations. The bowl to bowl inversion of the corannulene bowl with the lowest inversion barrier results in pseudorotation of the cyclotrimer, which gives rise to a symmetrized 1H NMR spectrum exhibiting 12 distinct proton signals. 1H NMR line shape analysis gives an estimation of the inversion barrier at 8.5 – 8.6 kcal/mol. The tetrameric hydrocarbon C80H32 was synthesized through the Diels-Alder reaction of the cyclotrimer and 1,2-didehydrocorannulene. The six membered rings adjacent to the central ring in the cyclotrimer are activated enough to react with another corannulyne. The tetramer exhibits different conformational and optical absorption properties when compared to the cyclotrimer. The tetramer (C80H32), which is highly nonplanar and sterically congested, represents the largest fully characterized oligomer of corannulyne reported to date. This is also the first reported example of a cycloaddition reaction in which a corannulene subunit acts as a diene. A tripodal molecular receptor (C87H54O6) with three corannulene pincers and a cyclotriveratrylene tether was synthesized. The molecular receptor was evaluated by 1H NMR titration in toluene-d8 for its ability to bind fullerenes. The experiment demonstrates the formation of 1:1 inclusion complexes of the molecular receptor with fullerenes and provides the association constants of 1500 plus or minus 50 and 1180 plus or minus 30 M-1 for C60 and C70, respectively.

Thesis advisor: Lawrence T. Scott / The Scott lab is interested in the functionalization of corannulene as a building block for large polycyclic aromatic hydrocarbons and carbon nanotube end-cap precursors. Toward that end, a new approach to the direct five-fold borylation of corannulene with iridium (I) catalysts via C-H activation has been explored. It has been discovered that the addition of catalytic amounts of base to the reaction mixture promotes the formation of symmetrical penta-borylated corannulene in a good yield on a sizable scale. All byproducts can be easily removed with iterative methanol washes. The present work also provides proof of the reversibility of the direct borylation reaction under the conditions used. Furthermore, modified Suzuki-Miyaura conditions have been employed to synthesize pentakis(2,6-dichlorophenyl)corannulene, a precursor for a [5,5] carbon nanotube end-cap. The reported reactions provide good yields and are scalable. / Thesis (MS) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

The first section of this dissertation (Chapter I-III) describes the development of new methodologies for the rhodium catalyzed C-N bond formation between sp3 hybridized carbon atom of phenyl substituted alpha-lactams and the nitrogen atom of indole derivatives. Phenyl substituted alpha-lactams generated in situ from the corresponding alpha-bromoamides reacted with indoles in the presence of rhodium catalyst to afford the ring opening products of alpha-lactams. The scope of this methodology was extended to various types of indole derivatives including electron donating and withdrawing substituents. Furthermore, a series of functionalized phenyl substituted alpha-lactams generated in situ reacted with indole to assess the viability of this methodology. The developed method provides an atom-economical approach for the formation of substituted alpha-amino amides in good to excellent yields. The main goal of the research described in the second section (Chapter IV-VII) is the synthesis of the corannulene-based molecular receptors with polar tethers and their immobilization on silica gel. First, we have considered a preparation of bis-corannulenoanthracene, formally possessing the pentacene core as a potential precursor for a series of barrelene based bis-corannulene receptors with polar groups. Bis-corannulenoanthracene was synthesized by the double Diels-Alder cycloaddition of isocorannulenofuran with bis-benzyne precursor, followed by deoxygenation of the endoxide adducts. While bis-corannulenoanthracene is stable enough to be isolated and stored, its pentacene core undergoes facile cycloaddition with maleic anhydride to afford bis-corannulene molecular receptor with the barrelene tether adorned with the anhydride moiety. The 1H NMR titration experiments carried out in chlorobenzene-d5 proved the high binding affinity of the receptor toward C60. In addition, the presence of polar anchors on its tether allowed for its deposition on silica gel through the (3-aminopropyl)triethoxysilane linker.

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