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Showing papers on "Fullerene published in 2003"


Journal ArticleDOI
26 Sep 2003-Science
TL;DR: Bowl-shaped π-conjugated compounds are important not only as model compounds of fullerenes but also as possible synthetic intermediates for artificially designed fullerene derivatives, such as hetero-fullererenes.
Abstract: Bowl-shaped π-conjugated compounds are important not only as model compounds of fullerenes but also as possible synthetic intermediates for artificially designed fullerene derivatives, such as hetero-fullerenes ([ 1 ][1]). Most of the attention has been focused on the compounds derived from C 5v

390 citations


Journal ArticleDOI
TL;DR: The electrochemical behavior of fullerene and its derivatives are reviewed with special reference to their catalytic and sensor applications in this article, where the potential for the preparation of electrochemical sensors and their application in electroanalytical chemistry are highlighted.
Abstract: The electrochemical behavior of fullerene and fullerene derivatives are reviewed with special reference to their catalytic and sensor applications. Recent work on carbon nanotubes, used as catalyst supports in heterogeneous catalysis and sensor development is also presented. An overview of recent progress in the area of fullerene electrochemistry is included. Several cases of electrocatalytic dehalogenation of alkyl halides, assisted by the electrode charge transfer to fullerenes, are discussed. Research work on the electrocatalysis of biomolecules, such as hemin, cytochrome c, DNA, coenzymes, glucose, ascorbic acid, dopamine, etc. have also been considered. Based on the studies of the interaction of fullerenes, fullerene derivatives, and carbon nanotubes with other molecules and biomolecules in particular, the possibilities for the preparation of electrochemical sensors and their application in electroanalytical chemistry are highlighted.

341 citations


Journal ArticleDOI
TL;DR: A novel class of biological membrane ion channel blockers called single-walled carbon nanotubes (SWNTs) are identified and postulate new uses for SWNTs in biological applications and provide unexpected insights into the current view of mechanisms governing the interaction of ion channels with blocking molecules.

320 citations


Book
27 Mar 2003
TL;DR: Graphite intercalation compounds are a new class of electronic materials that are classified as graphite-based host guest systems as mentioned in this paper, which have specific structural features based on the alternating stacking of graphite and guest intercalate sheets.
Abstract: Graphite intercalation compounds are a new class of electronic materials that are classified as graphite-based host guest systems. They have specific structural features based on the alternating stacking of graphite and guest intercalate sheets. The electronic structures show two-dimensional metallic properties with a large variety of features including superconductivity. They are also interesting from the point of two-dimensional magnetic systems. This book presents the synthesis, crystal structures, phase transitions, lattice dynamics, electronic structures, electron transport properties, magnetic properties, surface phenomena, and applications of graphite intercalation compounds. The applications covered include batteries, highly conductive graphite fibers, exfoliated graphite and intercalated fullerenes and nanotubes.

274 citations


Journal ArticleDOI
TL;DR: Using surface-enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopy, this article showed that composites based on polyaniline (PANI) and single-walled carbon nanotubes (SWNTs) are different when they are prepared by two different methods.
Abstract: Using surface-enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopy, we show that composites based on polyaniline (PANI) and single-walled carbon nanotubes (SWNTs) are different when they are prepared by two different methods: (1) by adding dispersed SWNTs to the polymer solutions and (2) by chemical polymerization of aniline in the presence of SWNTs. The difference originates from the irreversible chemical transformation of SWNTs in the polymerization medium. The synthesis medium used for the preparation of PANI transforms SWNTs into fragments of shorter length like closed-shell fullerenes. This explains the similarity of SERS and FTIR spectra of the composites PANI/SWNTs and PANI/C60 chemically prepared. All compounds exhibit an absorption band at 1144 cm-1 in their FTIR spectra, increasing with the carbon nanoparticules content, as a signature of a charge transfer between the constituents. Besides, the FTIR spectrum of the compounds obtained by adding SWNTs to the polymer...

217 citations


Journal ArticleDOI
TL;DR: The reaction of MoO3 and S at temperatures higher than 300 degrees C in an argon atmosphere provides a convenient and effective method for the synthesis of MoS2 nanocrystalline substances.
Abstract: The reaction of MoO3 and S at temperatures higher than 300 °C in an argon atmosphere provides a convenient and effective method for the synthesis of MoS2 nanocrystalline substances. MoS2 nanotubes and fullerene-like nanoparticles have been obtained by the reaction at 850 °C under well-controlled conditions. The influences of reaction temperature and duration were carefully investigated in this paper. All of the nanostructures were characterized by Xray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). A stepwise reaction model and rolling mechanism were proposed based on the experimental results.

202 citations


Journal ArticleDOI
TL;DR: Upon matrix-assisted laser desorption/ionization mass spectroscopy, the removal of organic addends from the fullerene derivative 1 encapsulating H2 and restoration of the pristine C60 cage, which retains approximately one-third of incorporated H2, have been observed.
Abstract: By applying high-pressure H2 to a new fullerene derivative, C63NO2SPh2Py (1), having a 13-membered-ring orifice, 100% incorporation of a H2 molecule into the fullerene cage has been achieved for the first time. This result substantiates the theoretical calculations indicating that the energy barrier required for H2 insertion through an orifice in 1 is considerably lower than that for the previously reported derivative with the largest orifice among open-cage fullerenes synthesized thus far. Upon matrix-assisted laser desorption/ionization mass spectroscopy, the removal of organic addends from the fullerene derivative 1 encapsulating H2 and restoration of the pristine C60 cage, which retains approximately one-third of incorporated H2, have been observed.

194 citations


Journal ArticleDOI
TL;DR: In this article, the C 1s spectra of fullerene C 60, highly oriented pyrolitic graphite (HOPG) and amorphous carbon (a-C) have been measured using X-ray photoemission.

175 citations


Journal ArticleDOI
TL;DR: Covalent sidewall functionalization of SWCNTs using addition chemistry has recently started to develop and theoretical and computational support is urgently needed to achieve control over chemoand regioselectivity of such additions.
Abstract: Covalent sidewall functionalization of SWCNTs using addition chemistry has recently started to develop. This approach is considered to be a very promising method for nanotube derivatization, since it leads to improved solubilities as well as processibilites and at the same time allows for the combination of the unique properties of SWCNTs with those of other compound classes. However, it is very difficult to achieve control over chemoand regioselectivity of such additions, which requires very 'hot' addends and drastic reaction conditions. This is one of the reasons why it is very difficult to characterize prepared functionalized SWCNTs as such. In particular, all experimental attempts to determine the precise location and mode of addition have failed to date. As a consequence, theoretical and computational support is urgently needed. The analysis of the principles of fullerene chemistry has shown that the reactivity of these spherical molecules towards addition reactions depends strongly on the curvature of their carbon framework. Among the stable fullerenes C60 is the smallest and as a consequence has the highest curvature. Because of the resulting pronounced pyramidalization of the C atoms within the rigid carbon framework, the outer convex surface is very susceptible towards addition reactions. 4] On the other hand, the inner concave surface of C60 is inert towards endohedral addition reactions. This is demonstrated, for example, by the remarkable stability of N@C60, in which a free nitrogen atom is encapsulated by the fullerene cage. In case of C60, the two sample. The probe light was provided by a 100 W tungsten lamp with wavelength selection being achieved by monochromators before and after the sample. Changes in optical density induced by the excitation pulse were monitored with a silicon photodiode and a home-built amplification/filtering system and digitised by a tetronix TDS220 digital storage oscilloscope.

169 citations


Journal ArticleDOI
TL;DR: In this paper, in situ transmission electron microscope (TEM) observations reveal sequences of fullerene coalescence induced by electron irradiation on pristine nanotube peapods, together with extensive theoretical investigations of the microscopic mechanism underlying this process.
Abstract: A fascinating structural transformation occurring inside single-walled carbon nanotubes (SWNTs) is the fullerene coalescence, which is responsible for forming stable zeppelinlike carbon molecules. We report in situ transmission electron microscope (TEM) observations revealing sequences of fullerene coalescence induced by electron irradiation on pristine nanotube peapods, together with extensive theoretical investigations of the microscopic mechanism underlying this process. TEM images indicate that the merging of fullerenes results in stable but corrugated tubules (5 to 7 Angstrom in diameter) confined within SWNTs. These observations have been confirmed using a combination of theoretical approaches based on molecular dynamics, empirical potentials, tight-binding methods, Monte Carlo techniques, and first principles calculations. We have fully elucidated the coalescence mechanism of fullerenes inside SWNTs under electron irradiation and thermal annealing. The process occurs via the polymerization Of C-60 molecules followed by surface reconstruction, which can be triggered either by the formation of vacancies (created under electron irradiation) or by surface-energy minimization activated by thermal annealing. These novel tubular forms of carbon contain hexagons, pentagons, heptagons, and octagons. The stability, electronic properties, and electron conductance of the novel tubules are strongly affected by the final geometry of the coalesced fullerene complex. The possibility of forming highly conducting and semiconducting tubular structures suggests new avenues in designing carbon nanowires with specific electronic characteristics.

167 citations



Journal ArticleDOI
TL;DR: Measurements are presented with a low-temperature atomic force microscope with pico-Newton force sensitivity that reveal the hidden surface atom in graphite.
Abstract: Carbon, the backbone material of life on Earth, comes in three modifications: diamond, graphite, and fullerenes. Diamond develops tetrahedral sp3 bonds, forming a cubic crystal structure, whereas graphite and fullerenes are characterized by planar sp2 bonds. Polycrystalline graphite is the basis for many products of everyday life: pencils, lubricants, batteries, arc lamps, and brushes for electric motors. In crystalline form, highly oriented pyrolytic graphite is used as a diffracting element in monochromators for x-ray and neutron scattering and as a calibration standard for scanning tunneling microscopy (STM). The graphite surface is easily prepared as a clean atomically flat surface by cleavage. This feature is attractive and is used in many laboratories as the surface of choice for “seeing atoms.” Despite the proverbial ease of imaging graphite by STM with atomic resolution, every second atom in the hexagonal surface unit cell remains hidden, and STM images show only a single atom in the unit cell. Here we present measurements with a low-temperature atomic force microscope with pico-Newton force sensitivity that reveal the hidden surface atom.

Journal ArticleDOI
TL;DR: This study presents clear evidence for the Marcus inverted region in both the electron-transfer reduction and oxidation of fullerenes in a truly intermolecular electron transfer.
Abstract: Pulse-radiolytic studies were performed to determine the rate constants of intermolecular electron transfer (k e t ) from fullerenes (C 6 0 , C 7 6 , and C 7 8 ) to a series of arene radical cations in dichloromethane. The one-electron oxidation potentials of the employed arenes-corresponding to the one-electron reduction potentials of arene π-radical cations-were determined in dichloromethane to evaluate the driving forces of electron-transfer oxidation of fullerenes with arene π-radical cations. The driving force dependence of log k e t shows a pronounced decrease towards the highly exothermic region, representing the first definitive confirmation of the existence of the Marcus inverted region in a truly intermolecular electron transfer. Electron-transfer reduction of fullerenes with anthracene radical anion was also examined by laser flash photolysis in benzonitrile. The anthracene radical anion was produced by photo-induced electron transfer from 10,10'-dimethyl-9,9',10,10'-tetrahydro-9,9'-bi-acridine [(AcrH) 2 ] to the singlet excited state of anthracene in benzonitrile. The rate constants of electron transfer (k e t ) from anthracene radical anion to C 6 0 , C 7 0 , and a C 6 0 derivative were determined from the decay of anthracene radical anion in the presence of various concentrations of the fullerene. Importantly, a significant decrease in the k e t value was observed at large driving forces (1.50 eV) as compared to the diffusion-limited value seen at smaller driving forces (0.96eV). In conclusion, our study presents clear evidence for the Marcus inverted region in both the electron-transfer reduction and oxidation of fullerenes.

Journal ArticleDOI
TL;DR: In the presence of the metal surface, nucleation of a closed cap or a capped single-wall carbon nanotube is overwhelmingly favored compared to any structure with dangling bonds or to a fullerene.
Abstract: The nucleation pathway for single-wall carbon nanotubes on a metal surface is demonstrated by a series of total energy calculations using density functional theory. Incorporation of pentagons at an early stage of nucleation is energetically favorable as they reduce the number of dangling bonds and facilitate curvature of the structure and bonding to the metal. In the presence of the metal surface, nucleation of a closed cap or a capped single-wall carbon nanotube is overwhelmingly favored compared to any structure with dangling bonds or to a fullerene.

Journal ArticleDOI
TL;DR: An acyclic dimer of a dendritic zinc porphyrin bearing six carboxylic acid functionalities interacts with fullerenes, such as C60 and C70, to form "supramolecular peapods", composed of a hydrogen-bonded zinc p Morphyrin nanotube and fullererenes (3).
Abstract: An acyclic dimer of a dendritic zinc porphyrin bearing six carboxylic acid functionalities (1acid) interacts with fullerenes, such as C60 and C70, to form “supramolecular peapods”, composed of a hydrogen-bonded zinc porphyrin nanotube and fullerenes (3). According to TEM, the peapods are very long (>1 μm) and have a uniform diameter of 15 nm. Without fullerenes, the zinc porphyrin dimer forms only a heavily entangled, irregular assembly. In contrast with 1acid, an ester version of the acyclic dimer without hydrogen-bonding capability (1ester) hardly interacts with fullerenes.


Journal ArticleDOI
TL;DR: A tetraphenylporphyrin bearing amide groups at the 3,5-positions of the meso-phenyl groups is assembled into a two-dimensional sheetlike structure and acts as an organogelator, and an amide-amide hydrogen-bonding interaction creates a cavity, the size of which is complementary to that of [60]fullerene, and these cavities are connected to provide a one-dimensional multicapsular structure.
Abstract: A tetraphenylporphyrin (1b) bearing amide groups at the 3,5-positions of the meso-phenyl groups is assembled into a two-dimensional sheetlike structure and acts as an organogelator. When [60]fullerene was added, the sheetlike structure was dramatically changed into a one-dimensional fibrous structure, and both the gelation ability and the gel stability were improved. The stoichiometry between [60]fullerene and 1b was determined to be 1:2. Examination utilizing SEM and TEM observations, UV−vis and ATR IR spectral analyses, and XRD analysis revealed that an amide−amide hydrogen-bonding interaction creates a cavity, the size of which is complementary to that of [60]fullerene, and these cavities are connected by another amide−amide hydrogen-bonding interaction to provide a one-dimensional multicapsular structure. This is a novel example that the superstructure constructed in an organogel system is drastically changed by added [60]fullerene.


Journal ArticleDOI
TL;DR: Electrochemical measurements found compounds 9 and 10, which have two carbonyl groups on the rim of the orifice, were found to be more readily reduced than C(60) itself, while the first reduction potentials of other open-cage fullerene derivatives, 5, 11, and 15, were nearly the same as that of C( 60).
Abstract: A thermal liquid-phase reaction of fullerene C(60) with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine afforded aza-open-cage fullerene derivative 5 having an eight-membered-ring orifice on the fullerene cage. Compound 5 was found to undergo oxidative ring-enlargement reactions with singlet oxygen under photo-irradiation to give azadioxo-open-cage fullerene derivatives 9 and 10, which have a 12-membered-ring orifice, in addition to a small amount of azadioxa-open-cage fullerene derivative 11, which has a 10-membered-ring orifice. A thermal reaction of 9 with elemental sulfur in the presence of tetrakis(dimethylamino)ethylene resulted in further ring-enlargement to give azadioxothia-open-cage fullerene derivative 15, which has a 13-membered-ring orifice. The structures of 5 and 15 were determined by X-ray crystallography, while those of 9, 10, and 11 were confirmed by the agreement of observed (13)C NMR spectra with those obtained by DFT-GIAO calculations. These reactions were rationalized based on the results of molecular orbital calculations. Following electrochemical measurements, compounds 9 and 10, which have two carbonyl groups on the rim of the orifice, were found to be more readily reduced than C(60) itself (the first reduction potential was found to be 0.2 V lower than that of C(60)), while the first reduction potentials of other open-cage fullerene derivatives, 5, 11, and 15, were nearly the same as that of C(60).

Journal ArticleDOI
TL;DR: In this paper, the electrostatic potentials on both the outer and the inner surfaces of 10 single-walled model systems have been computed at the Hartree−Fock STO-5G/STO-3G level.
Abstract: To help understand and predict nanotube interactions, the electrostatic potentials on both the outer and the inner surfaces of 10 single-walled model systems have been computed at the Hartree−Fock STO-5G//STO-3G level. All structures were optimized computationally. Both carbon and boron/nitrogen tubes were studied, including the open and closed (5,5) and the open (6,1), (7,1), and (8,1), plus fullerene for comparison. Hydrogen atoms were introduced at the ends of the open tubes, to satisfy the unfulfilled valencies. The surface potentials were characterized in terms of both site-specific and global properties: positive and negative extrema and average values, average deviation, positive and negative variances, and electrostatic balance. The all-carbon systems, the closed (5,5) and fullerene, are very weakly positive on most of the outer and all of the inner surfaces, the latter potentials being somewhat stronger. In contrast, the open carbon tubes with charge-donating hydrogens at the ends are slightly n...

Journal ArticleDOI
TL;DR: Structures and recombination routes for interstitial-vacancy pairs in graphite are examined and it is expected that similar defects to form in carbon nanostructures such as nanotubes, nested fullerenes, and onions under irradiation.
Abstract: The atomic processes associated with energy storage and release in irradiated graphite have long been subject to untested speculation. We examine structures and recombination routes for interstitial-vacancy (I-V) pairs in graphite. Interaction results in the formation of a new metastable defect (an intimate I-V pair) or a Stone-Wales defect. The intimate I-V pair, although 2.9 eV more stable than its isolated constituents, still has a formation energy of 10.8 eV. The barrier to recombination to perfect graphite is calculated to be 1.3 eV, consistent with the experimental first Wigner energy release peak at 1.38 eV. We expect similar defects to form in carbon nanostructures such as nanotubes, nested fullerenes, and onions under irradiation.


Journal ArticleDOI
TL;DR: In this article, the mass selected ion yield as a function of IR laser frequency yields the IR-REMPI (infrared resonance enhanced multiphoton ionization) spectrum of the molecule or cluster.
Abstract: Resonant IR excitation of gas-phase molecules and clusters can lead to superhot species that thermally emit an electron. Monitoring the mass selected ion yield as a function of IR laser frequency yields the IR-REMPI (infrared resonance enhanced multiphoton ionization) spectrum of the molecule or cluster. Although this IR-REMPI spectrum is not the same as the linear absorption spectrum, it can be quite similar and it yields valuable information on the IR optical properties of the species investigated. In this article, the method and the necessary tools are presented. Results from experiments on fullerenes, metal carbide, metal oxide, and metal nitride clusters are shown.


Journal ArticleDOI
TL;DR: The structural and electrical properties of an electron-beam (EB)-irradiated C60 film have been examined at room temperature, using in situ infrared (IR) spectroscopy and ex situ four-probe measurements as mentioned in this paper.
Abstract: The structural and electrical properties of an electron-beam (EB)-irradiated C60 film have been examined at room temperature, using in situ infrared (IR) spectroscopy and ex situ four-probe measurements. IR results show that the irradiated film is neither graphite nor carbon nanotube-like but a peanut-shaped C60 polymer. Current–voltage curve shows that the polymer exhibits a metallic property with a drastically reduced resistivity of 7 Ω cm in comparison with 108–1014 Ω cm for solid C60. This indicates the possibility of applying C60 molecules in EB nanofabrication processes and large potential for developing carbon-based nanodevices.

Journal ArticleDOI
TL;DR: In this paper, the relative stability of bucky diamonds and carbon onions has been compared with previous results for nanodiamond and fullerenes, showing that bucky diamond occupies a coexistence region, spanning the calculated upper limit of fullerene stability and the lower limit of ndiamond stability.
Abstract: The transformation of nanodiamonds into carbon onions, and vice versa, has lead to the introduction of a new intermediate phase of carbon, coined "bucky diamond," with a diamond core encased in an onion-like shell. Using a model based on the atomic heat of formation to describe the phase stability of carbon nanoparticles, we have calculated the relative stability of bucky diamonds and carbon onions for comparison with previous results for nanodiamond and fullerenes. Our results show that bucky diamond occupies a coexistence region, spanning the calculated upper limit of fullerene stability and the lower limit of nanodiamond stability.

Journal ArticleDOI
TL;DR: In this article, a number of composite-like samples of γ-cyclodextrin and HiPco carbon nanotubes were prepared using a simple grinding procedure, which has been reported to cut HiP co carbon nanitubes, and analyzed using absorption and Raman spectroscopy and differential scanning calorimetry.
Abstract: In this study a number of composite-like samples of γ-cyclodextrin and HiPco carbon nanotubes were prepared. The first sample was prepared by a simple grinding procedure, which has been reported to cut HiPco carbon nanotubes. The other samples were obtained via a refluxing procedure analogous to similar studies on other fullerenes and γ-cyclodextrin. The samples were analyzed using absorption and Raman spectroscopy, and differential scanning calorimetry. The results presented show clear evidence of an intermolecular interaction between γ-cyclodextrin and single-walled carbon nanotubes.

Journal ArticleDOI
TL;DR: In this article, total energy electronic-structure calculations of fullerenes encapsulated in zigzag carbon nanotubes (so-called peapods) are presented.
Abstract: We report total-energy electronic-structure calculations that provide energetics and electronic structures of fullerenes encapsulated in zigzag carbon nanotubes (so-called peapods). It is found that the space between the nanotube and the encapsulated fullerenes is a decisive factor to determine the energetics for the encapsulation process of the fullerenes in the nanotubes and the stability of resultant structures. The reaction energies for the encapsulation processes exhibit common characteristics depending on the space inside the tube, irrespective of their metallic and semiconducting properties. It is also found that the electronic structures of peapods depend on the space and that they reflect electron states of the encapsulated fullerenes. A relative energy position of the lowest unoccupied states of the encapsulated fullerenes modulates the energy gap of the semiconducting nanotubes. Further, the interwall spacing results in a significant shift of the electron states that have originated from the fullerenes. Our results indicate that the energy gap of the semiconducting peapods exhibits interesting variation depending on both the space and the fullerenes and suggest the possibility of band-gap engineering of the all carbon materials.


Journal ArticleDOI
TL;DR: In this article, total energy electronic structure calculations of various fullerenes encapsulated in carbon nanotubes and the electronic structures of resulting carbon peapods are presented. But they do not consider the effect of encapsulation on the electron states.
Abstract: We report total-energy electronic structure calculations that provide energetics of encapsulation of various fullerenes in carbon nanotubes and electronic structures of resulting carbon peapods. We find that the electron states of the peapods depend on the space in the nanotubes and that they reflect electron states of the encapsulated fullerenes. The deep energy position of the lowest unoccupied state of fullerenes as well as hybridization between $\ensuremath{\pi}$ states of the fullerenes and the nearly free-electron states of the nanotubes causes a multicarrier character in the peapods.