Sample records for c-60 molecule adsorbed

  1. Spectroscopic observations of the displacement dynamics of physically adsorbed molecules-CO on C60 (United States)

    Yuan, Chunqing; Yates, John T.


    In this paper, we observed physically adsorbed CO molecules on C60 surface being displaced by impinging noble gas atoms (He, Ne, Ar, Kr), either through a dynamic displacement process or an exothermic replacement process, depending on their adsorption energies. This displacement mechanism could shift from one to the other depending on the surface coverage and temperature. Furthermore, rotational energy of the impinging molecules may also contribute to the dynamic displacement process by supplying additional energy.

  2. Controlled contact to a C-60 molecule

    DEFF Research Database (Denmark)

    Neel, N.; Kröger, J.; Limot, L.;


    The tip of a low-temperature scanning tunneling microscope is approached towards a C-60 molecule adsorbed at a pentagon-hexagon bond on Cu(100) to form a tip-molecule contact. The conductance rapidly increases to approximate to 0.25 conductance quanta in the transition region from tunneling...

  3. Electronic structure and electrical transport characteristics of C60, 2C60 and 4C60 fullerene molecules

    Institute of Scientific and Technical Information of China (English)

    SHEN Haijun; MU Xiancai


    The extended Hückel method and the Green's function method were used to calculate the electronic struc-ture and electrical transport of Au electrode-C60,2C60 or 4C60 fullerene-Au electrode systems.Furthermore,their electronic structure and electrical transport characteristics were com-pared and analyzed.The results show that (I) owing to the contact with the Au electrodes,the C60,2C60 and 4C60 mole-cules change in their electronic structures ignificantly,and their energy gaps between LUMO and HOMO are narrow;(ii) the bonding between C60,2C60 or 4C60 fullerene and Au electrodes is partially covalent and partially electrovalent;and (iii) the conductance of the three fullerenes conforms to the order of C60>2C60>4C60.

  4. Hindered rotation of a copper phthalocyanine molecule on C60 : Experiments and molecular mechanics calculations

    NARCIS (Netherlands)

    Fendrich, M.; Wagner, Th.; Stöhr, M.; Möller, R.


    If copper phthalocyanine (CuPc) molecules are deposited on a Au(111) surface covered with a monolayer of C60, the molecules are found to adsorb individually onto the close-packed layer of C60. As the adsorption site of the CuPc is not symmetric with respect to the underlying C60 layer, the CuPc mole

  5. Electronic structures of the icosahedral C 60H 60 and C 60F 60 molecules (United States)

    Cioslowski, Jerzy


    Electronic structures of the icosahedral C 60H 60 hydrocarbon and its perfluoro analog, C 60F 60, are examined at the HF/4-31G and HF/6-31G** levels. The calculated CC bond lengths are as large as 1.57 Å in C 60H 60 and 1.63 Å in C 60F 60. The bond lengthening is attributed to the HH and FF steric interactions rather than to rehybridization effects. Topological analysis of the electron densities reveals the presence of curve CC bond paths. In addition, FF bond paths are found in C 60F 60 indicating strong non-bonded interaction between the fluorine atoms. The same conclusion is reached from the calculated energy of the isodesmic transfluorination reaction involving the C 2H 6, C 2F 6, C 60H 60, and C 60F 60 molecules.

  6. Fullerene Molecule Strain in $RbC_{60}$

    CERN Document Server

    Aksenov, V L; Forró, L; Khasanov, S S; Chernyshev, V V; Shakhmatov, V S


    Strain displacements of carbon atoms in a C$_60$ molecule in the $Pnnm$ phase of the RbC$_60$ fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C$_60$ is equal to 1.69(1) $\\AA$, the rotation angle of the molecule about the polymeric direction is 47.0(3)$^0$.

  7. An ab initio study of the field-induced position change of a C-60 molecule adsorbed on a gold tip

    DEFF Research Database (Denmark)

    Stadler, Robert; Kubatkin, Sergey; Bjørnholm, Thomas


    be based on such junctions if the mechanism of the process is understood. We present density functional theory based plane wave calculations, where we studied the energetics of the molecule's adsorption under the influence of an external field. Particular emphasis was placed on investigating a possible...

  8. Fullerene molecule strain in RbC 60 (United States)

    Aksenov, V. L.; Ossipyan, Yu. À.; Forro, L.; Khasanov, S.; Chernyshev, V. V.; Shakhmatov, V. S.


    Strain displacements of carbon atoms in a Ñ 60 molecule in the Pnnm phase of the RbC 60 fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C 60 is equal to 1.69(1) Å, the rotation angle of the molecule about the polymeric direction is 47.0(3)°.

  9. Quantum Theory for Large Molecules $C_{60}$ Diffraction

    CERN Document Server

    Wu, Xiang-Yao; Liu, Xiao-Jing; Ba, Nuo; Wu, Yi-Heng; Tang, Hou-Li; Wang, Jing; Zhang, Si-Qi


    Diffraction phenomena of large molecules have been studied in many experiments, and these experiments are described by many theoretical works. In this paper, we study $C_{60}$ molecules single and double-slit diffraction with quantum theory approach, and we pay close attention to the $C_{60}$ diffraction experiment carried out by A.Zeilinger in 1999. In double-slit diffraction, we consider the decoherence effect, and find the theoretical results are good agreement with experimental data.

  10. Structure and dynamics of C60 molecules on Au(111)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Heekeun [Penn State University; Schwarze, A [Penn State University; Diehl, R D [Penn State University; Pussi, K [Lappeenranta University of Technology; Colombier, A [Universite de Lorraine; Gaudry, E. [Universite de Lorraine; Ledieu, J [Universite de Lorraine; McGuirk, G M [Universite de Lorraine; Serkovic Loli, L N [Universite de Lorraine; Fournee, V [Universite de Lorraine; Wang, Lin-Lin [Ames Laboratory; Schull, G [Universite de Strasbourg; Berndt, R [Christian-Albrechts-Universitt zu Kiel


    Earlier studies of C60 adsorption on Au(111) reported many interesting and complex features. We have performed coordinated low-energy electron diffraction, scanning tunneling microscopy (STM), and density functional theory studies to elucidate some of the details of the monolayer commensurate (2√3 × 2√3)R30° phase. We have identified the adsorption geometries of the two states that image as dim and bright in STM. These consist of a C60 molecule with a hexagon side down in a vacancy (hex-vac) and a C60 molecule with a carbon-carbon 6:6 bond down on a top site (6:6-top), respectively. We have studied the detailed geometries of these states and find that there is little distortion of the C60 molecules, but there is a rearrangement of the substrate near the C60 molecules. The two types of molecules differ in height, by about 0.7 Å, which accounts for most of the difference in their contrast in the STM images. The monolayer displays dynamical behavior, in which the molecules flip from bright to dim, and vice versa. We interpret this flipping as the result of the diffusion of vacancies in the surface layers of the substrate. Our measurements of the dynamics of this flipping from one state to the other indicate that the activation energy is 0.66 ± 0.03 eV for flips that involve nearest-neighbor C60 molecules, and 0.93 ± 0.03 for more distant flips. Based on calculated activation energies for vacancies diffusing in Au, we interpret these to be a result of surface vacancy diffusion and bulk vacancy diffusion. These results are compared to the similar system of Ag(111)-(2√3 × 2√3)R30°-C60. In both systems, the formation of the commensurate C60 monolayer produces a large number of vacancies in the top substrate layer that are highly mobile, effectively melting the interfacial metal layer at temperatures well below their normal melting temperatures.

  11. Wave-particle duality of C(60) molecules. (United States)

    Arndt, M; Nairz, O; Vos-Andreae, J; Keller, C; van der Zouw, G; Zeilinger, A


    Quantum superposition lies at the heart of quantum mechanics and gives rise to many of its paradoxes. Superposition of de Broglie matter waves' has been observed for massive particles such as electrons, atoms and dimers, small van der Waals clusters, and neutrons. But matter wave interferometry with larger objects has remained experimentally challenging, despite the development of powerful atom interferometric techniques for experiments in fundamental quantum mechanics, metrology and lithography. Here we report the observation of de Broglie wave interference of C(60) molecules by diffraction at a material absorption grating. This molecule is the most massive and complex object in which wave behaviour has been observed. Of particular interest is the fact that C(60) is almost a classical body, because of its many excited internal degrees of freedom and their possible couplings to the environment. Such couplings are essential for the appearance of decoherence, suggesting that interference experiments with large molecules should facilitate detailed studies of this process.

  12. The nano-science of C60 molecule

    Directory of Open Access Journals (Sweden)


    Full Text Available   Over the past few years, nano-science and its associated nano-technology have emerged into prominence in research instiutions across the world. They have brought about new scientific and engineering paradigms, allowing for the manipulation of single atoms and molecules, designing and fabricating new materials, atom-by-atom, and devices that operate on significantly reduced time and length scales. One important area of research in nano-science and nano-technology is carbon-based physics in the form of fullerene physics. The C60 molecule, and other cage-like fullerenes, together with carbon nanotubes provide objects that can be combined to generate three-dimensional functional structures for use in the anticipated nano-technology of future. The unique properties of C60 can also be exploited in designing nano-phase thin films with applications in nanoscopic device technology and processes such as nano-lithography. This requires a deep understanding of the highly complex process of adsorption of this molecule on a variety of substrates. We review the field of nano-scale nucleation and growth of C60 molecules on some of the technologically important substrates. In addition to experimental results, the results of a set of highly accurate computational simulations are also reported.

  13. Direct observation of hindered eccentric rotation of an individual molecule : Cu-phthalocyanine on C60

    NARCIS (Netherlands)

    Stöhr, Meike; Wagner, T; Gabriel, M; Weyers, B; Moller, R


    Individual Cu-phthalocyanine molecules have been investigated by scanning tunnel microscopy on a closed packed film of C-60 at various temperatures. The molecules are found to bind asymmetrically to one C-60. While they remain in one position at low temperature, they can hop between six equivalent p

  14. Formation of clusters composed of C60 molecules via self-assembly in critical fluids (United States)

    Fukuda, Takahiro; Ishii, Koji; Kurosu, Shunji; Whitby, Raymond; Maekawa, Toru


    Fullerenes are promising candidates for intelligent, functional nanomaterials because of their unique mechanical, electronic and chemical properties. However, it is necessary to invent some efficient but relatively simple methods of producing structures composed of fullerenes for the development of nanomechatronic, nanoelectronic and biochemical devices and sensors. In this paper, we show that various structures such as straight fibres, networks formed by fibres, wide sheets and helical structures, which are composed of C60 molecules, are created by placing C60-crystals in critical ethane, carbon dioxide and xenon even though C60 molecules do not dissolve or disperse in the above fluids. It is supposed, judging by the intermolecular potentials between C60 and C60, between C60 and ethane, and between ethane and ethane, that C60-clusters grow with the assistance of solvent molecules, which are trapped between C60 molecules under critical conditions. This room-temperature self-assembly cluster growth process in critical fluids may open up a new methodology of forming structures built up with fullerenes without the need for any ultra-fine processing technologies.

  15. Orientational Order of C60 Molecules in Low-dimensional Lattices

    Institute of Scientific and Technical Information of China (English)

    Hou Jianguo


    The orientational order is an important concept of the materials composed of large molecules or clusters. Using high-resolution scanning tunneling microscopy, we have studied the orientational order of two kinds of typical low-dimensional C60 lattices: two-dimensional molecules array and C60(111) multi-layer film surface. Due to the change of the crystal field, their orientational orders are distinctly different from those in bulk system, and some unique phenomena appear.

  16. On the chemical behavior of C60 hosting H2O and other isoelectronic neutral molecules. (United States)

    Galano, Annia; Pérez-González, Adriana; del Olmo, Lourdes; Francisco-Marquez, Misaela; León-Carmona, Jorge Rafael


    The density functional theory (DFT) was used to investigate the chemical behavior of C60 hosting neutral guest molecules (NGM). The deformed atoms in molecules (DAM) allowed identifying the regions of electron density depletion and accumulation. The studied NGM are CH4, NH3, H2O, and HF. Based on dipole moment and polarizabilities analyses it is predicted that the NGM@C60 should be more soluble in polar solvents than C60. The deformations on the surface electron density of the fullerenes explain this finding, which might be relevant for further applications of these systems. It was found that the intrinsic reactivity of studied NGM@C60 is only moderately higher than that of C60. This trend is supported by the global reactivity indexes and the frontier orbitals analyses. The free radical scavenging activity of the studied systems, via single electron transfer, was found to be strongly dependent on the chemical nature of the reacting free radical. The presence of the studied NGM inside the C60 influences only to some extent the reactivity of C60 toward free radicals. The distortion of the electron density on the C60 cage, caused by the NGM, is directly related to the electron withdrawing capacity of the later.

  17. Effect of doping of N and B atoms on thermoelectric properties of C60 molecule

    Indian Academy of Sciences (India)

    Mojtaba Yaghobi; Fazel Ardeshir Larijani


    In this work, the doping effect on the thermoelectric properties of the C60 molecule (fullerene) was studied by considering inelastic electron–phonon interactions. It is seen that the maximum value of thermal conductance (max) with respect to the molecules are max(C59N) < max(C60) < max(C59B). Also, the oscillatory behaviour of thermal conductance is dramatically dependent on the type of molecules. The values of figure of merit (ZT) against energy and with respect to the type of molecules are between 0.25 × 10−5 and 0.194 × 10−3 and effect of the type of molecules is small on the minimum value of ZT.

  18. Spectromicroscopy of C60 and azafullerene C59N: Identifying surface adsorbed water (United States)

    Erbahar, Dogan; Susi, Toma; Rocquefelte, Xavier; Bittencourt, Carla; Scardamaglia, Mattia; Blaha, Peter; Guttmann, Peter; Rotas, Georgios; Tagmatarchis, Nikos; Zhu, Xiaohui; Hitchcock, Adam P.; Ewels, Chris P.


    C60 fullerene crystals may serve as important catalysts for interstellar organic chemistry. To explore this possibility, the electronic structures of free-standing powders of C60 and (C59N)2 azafullerenes are characterized using X-ray microscopy with near-edge X-ray adsorption fine structure (NEXAFS) spectroscopy, closely coupled with density functional theory (DFT) calculations. This is supported with X-ray photoelectron spectroscopy (XPS) measurements and associated core-level shift DFT calculations. We compare the oxygen 1s spectra from oxygen impurities in C60 and C59N, and calculate a range of possible oxidized and hydroxylated structures and associated formation barriers. These results allow us to propose a model for the oxygen present in these samples, notably the importance of water surface adsorption and possible ice formation. Water adsorption on C60 crystal surfaces may prove important for astrobiological studies of interstellar amino acid formation.

  19. The caged state of some small molecules in the C60 cage

    Institute of Scientific and Technical Information of China (English)


    The potential energy curves of some small molecules, H2, N2, O2, F2, HF, CO and NO, in the caged state within C60 cage and in the free state have been calculated by the quantum-chemical method AM1. In this study, the focus is on the cage effect of C60, and the concept of caged state is put forward. The results show that the bond lengths in the caged states are not much different from those in their corresponding free states, but the bond intensities in the caged states are much greater than those in their corresponding free states.

  20. Interceptor effect of C60 fullerene on the in vitro action of aromatic drug molecules. (United States)

    Skamrova, Galyna B; Laponogov, Ivan; Buchelnikov, Anatoly S; Shckorbatov, Yuriy G; Prylutska, Svitlana V; Ritter, Uwe; Prylutskyy, Yuriy I; Evstigneev, Maxim P


    C60 fullerenes are spherical molecules composed purely of carbon atoms. They inspire a particularly strong scientific interest because of their specific physico-chemical properties and potential medical and nanotechnological applications. In this work we are focusing on studying the influence of the pristine C60 fullerene on biological activity of some aromatic drug molecules in human buccal epithelial cells. Assessment of the heterochromatin structure in the cell nucleus as well as the barrier function of the cell membrane was performed. The methods of cell microelectrophoresis and atomic force microscopy were also applied. A concentration-dependent restoration of the functional activity of the cellular nucleus after exposure to DNA-binding drugs (doxorubicin, proflavine and ethidium bromide) has been observed in human buccal epithelial cells upon addition of C60 fullerene at a concentration of ~10(-5 )M. The results were shown to follow the framework of interceptor/protector action theory, assuming that non-covalent complexation between C60 fullerene and the drugs (i.e., hetero-association) is the major process responsible for the observed biological effects. An independent confirmation of this hypothesis was obtained via investigation of the cellular response of buccal epithelium to the coadministration of the aromatic drugs and caffeine, and it is based on the well-established role of hetero-association in drug-caffeine systems. The results indicate that C60 fullerene may reverse the effects caused by the aromatic drugs, thereby pointing out the potential possibility of the use of aromatic drugs in combination with C60 fullerene for regulation of their medico-biological action.

  1. Small Molecules in C60 and C70: Which Complexes Could Be Stabilized? (United States)

    Korona, Tatiana; Dodziuk, Helena


    The recent syntheses of complexes involving some small molecules in opened fullerenes and those of hydrogen molecule(s) in C60 and C70 are accompanied in the literature by numerous computations for endohedral fullerene complexes which cope with the problem of the stability of these complexes. In this contribution, stabilization energies of endohedral complexes of C60 and C70 with H2, N2, CO, HCN, H2O, H2S, NH3, CH4, CO2, C2H2, H2CO, and CH3OH guests have been estimated using symmetry-adapted perturbation theory, which, contrary to the standard DFT and some other approaches, correctly describes the dispersion contribution of the host-guest interactions. On the basis of these calculations, the endohedral complexes with all these guests were found stable in the larger fullerene, while the C60 cage was found too small to host the latter four molecules. Except for H2 and H2CO, a stabilization effect for most guests in the C60 cage is about 30 kJ/mol. For H2 and H2O guests, a typical supramolecular effect is observed; namely, the stabilization in the smaller cage is equal to or larger than that in the larger C70 host. Except for the water molecule where the induction interaction plays a non-negligible role, in all complexes the main stabilization effect comes from the dispersion interaction. The information on the stability of hypothetical endohedral fullerene complexes and physical factors contributing to it can be of importance in designing future experiments contributing to their applications.

  2. Nanoelectromechanical switch operating by tunneling of an entire C-60 molecule

    DEFF Research Database (Denmark)

    Danilov, Andrey V.; Hedegård, Per; Golubev, Dimitrii S.;


    We present a solid state single molecule electronic device where switching between two states with different conductance happens predominantly by tunneling of an entire C-60 molecule. This conclusion is based on a novel statistical analysis of similar to 10(5) switching events. The analysis yields...... (i) the relative contribution of tunneling, current induced heating and thermal fluctuations to the switching mechanism, (ii) the voltage dependent energy barrier (similar to 100-200 meV) separating the two states of the switch and (iii) the switching attempt frequency, omega(0) corresponding to a 2...

  3. Algebraic theory of endohedrally confined diatomic molecules: application to H$_2$@C$_{60}$

    CERN Document Server

    Fortunato, Lorenzo


    A simple and yet powerful approach for modeling the structure of endohedrally confined diatomic molecules is introduced. The theory, based on a $u(4)\\oplus u(3)$ dynamical algebra, combines the vibron model with an isotropic three dimensional oscillator. The first describes the internal roto-vibrations degrees of freedom of the molecule, while the second takes into account the confined molecule center-of-mass degrees of freedom. A resulting subalgebra chain is connected to the underlying physics and the model is applied to the prototypical case of H$_2$ caged in a fullerene molecule. The spectrum of the supramolecular complex H$_2$@C$_{60}$ is described with a few parameters and predictions for not yet detected levels are made. Our fits suggest that the quantum numbers of a few lines should be reassigned to obtain better agreement with data.

  4. Reversible dimerization of C60 molecules in the crystal structure of the bis(arene)chromium fulleride [Cr(C7H8)]2C60. (United States)

    Hönnerscheid, Andreas; Dinnebier, Robert; Jansen, Martin


    Bis(toluene)chromium fulleride, [Cr(C(7)H(8))(2)]C(60), has been synthesized as a black microcrystalline powder from C(60) and [Cr(C(7)H(8))(2)] in toluene. [Cr(C(7)H(8))(2)]C(60) is an ionic compound in which the fullerene is negatively charged and the bis(toluene)chromium molecule positively charged. At T = 250 K a reversible first-order phase transition from a primitive cubic high-temperature phase to a triclinic low-temperature phase occurs. The high-temperature phase [Pm3 macro m, a = 9.9840 (1) A, T = 295 K] is composed of dynamically disordered fulleride anions and bis(toluene)chromium(I) cations in a CsCl-type arrangement. The triclinic low-temperature modification [P1 macro, a = 13.6414 (8), b = 13.8338 (7), c = 13.8548 (7) A, alpha = 91.830 (3), beta = 116.776 (2), gamma = 119.333 (2) degrees, T = 235 K] consists of ordered C(60) dimers and two crystallographically distinct bis(toluene)chromium entities.

  5. Electrodynamical Forbiddance of the Strong Quadrupole Light-Molecule Interaction and Its Experimental Manifestation in Fullerene C60

    CERN Document Server

    Chelibanov, V P


    It is demonstrated that the forbidden lines, which must be present in the SERS, TERS and SEIRA spectra of molecules with sufficiently high symmetry, associated with a strong quadrupole light-molecule interaction, are absent in the fullerene C60. This result is an experimental manifestation of an electrodynamical forbiddance of the strong quadrupole light-molecule interaction, which must be not only in molecules with cubic symmetry groups, but in the fullerene C60 also.

  6. Gas phase ion-molecule reactions of buckminsterfullerene C60 with some small organic compounds in mass spectrometer

    Institute of Scientific and Technical Information of China (English)

    刘淑莹; 郭兴华; 刘子阳; 倪嘉缵


    In chemical ionization mass spectrometry (CIMS) gas phase C60+ or C60can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions A dozen of gas-phase adduct ions of C60 are observed, and most of them contain chlorine atoms The results of the comparison and analysis show that the relative intensities of adduct ions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C60+ or C60. This indicates that the alkene-like C60+ or C60 can act as a radical sponge in addition reactions.

  7. Molecular orientation and lattice ordering of C60 molecules on the polar FeO/Pt(111) surface (United States)

    Qin, Zhihui; Liu, Cunding; Chen, Jian; Guo, Qinmin; Yu, Yinghui; Cao, Gengyu


    C60 molecules assemble into close packing layer under the domination of the intermolecular interaction when deposited onto Pt(111)-supported FeO layer kept at 400 K. From corresponding high resolution scanning tunneling microscopy (STM) image, a kind of C60 molecular orientational ordering stabilized by the intermolecular interaction is revealed as C60/FeO(111)-(√133 × √133) R17.5° structure and determined from the commensurability between the C60 nearest-neighbor distance and the lattice of the underlying oxygen layer. Moreover, due to the inhomogeneously distributed work function of the underlying FeO layer, the C60 molecular electronic state is periodically modulated resulting in a bright-dim STM contrast. In addition, one coincidence lattice ordering is determined as 8 × 8 superstructure with respect to the C60 primitive cell, which overlays a 3 × 3 moiré cell of the underlying FeO layer.

  8. Coupling of Surface and Volume Dipole Oscillations in C-60 Molecules

    CERN Document Server

    Brack, M; Murthy, M V N


    We first give a short review of the ``local-current approximation'' (LCA), derived from a general variation principle, which serves as a semiclassical description of strongly collective excitations in finite fermion systems starting from their quantum-mechanical mean-field ground state. We illustrate it for the example of coupled translational and compressional dipole excitations in metal clusters. We then discuss collective electronic dipole excitations in C$_{60}$ molecules (Buckminster fullerenes). We show that the coupling of the pure translational mode (``surface plasmon'') with compressional volume modes in the semiclasscial LCA yields semi-quantitative agreement with microscopic time-dependent density functional (TDLDA) calculations, while both theories yield qualitative agreement with the recent experimental observation of a ``volume plasmon''.

  9. Hydrophobic Porous Material Adsorbs Small Organic Molecules (United States)

    Sharma, Pramod K.; Hickey, Gregory S.


    Composite molecular-sieve material has pore structure designed specifically for preferential adsorption of organic molecules for sizes ranging from 3 to 6 angstrom. Design based on principle that contaminant molecules become strongly bound to surface of adsorbent when size of contaminant molecules is nearly same as that of pores in adsorbent. Material used to remove small organic contaminant molecules from vacuum systems or from enclosed gaseous environments like closed-loop life-support systems.

  10. Study of Small Molecule Organic Solar Cells Performance Based on Boron Subphthalocyanine Chloride and C60

    Directory of Open Access Journals (Sweden)

    Jhong-Ciao Ke


    Full Text Available The small molecule organic solar cells based on boron subphthalocyanine chloride (SubPc and C60 by varying the SubPc layer thickness from 3 nm to 21 nm were fabricated. The maximum power conversion efficiency (PCE of 1.47% was obtained at the 9 nm SubPc layer under 100 mW/cm2 AM1.5G illumination, which is attributed to reach the optimal balance between the light absorption efficiency and the carrier collection efficiency in the device. To increase the open-circuit voltage (Voc of device, the molybdenum oxide (MoO3 and poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate were inserted between the indium tin oxide and the SubPc layer, respectively. Finally, the Voc of device increased from 0.46 V to 1 V by using MoO3 buffer layer, resulting in the fact that the PCE of device increased from 1.47% to 2.52%.

  11. Rotations and vibrations of water molecule inside the fullerene cage: infrared study of H2O@C60 (United States)

    Room, Toomas; Shugai, A.; Nagel, U.; Mamone, S.; Krachmalnicoff, A.; Whitby, R. J.; Levitt, M. H.; Nishida, T.; Murata, Y.; Lei, Xuegong; Li, Yongjun; Turro, N. J.


    Water is the second molecule after hydrogen what has been trapped inside the cage of a C60 molecule by the molucular surgery method. We studied isolated water molecule isotopologs H2O, D2O, and HDO in the solid phase at cryogenic temperatures using IR spectroscopy. The water molecule rotation transitions were observed in the THz and vibration-rotation transitions in the mid-IR range. The slow conversion between para and ortho water allowed us to record the time evolution of spectra and to separate ortho and para absorption lines of water. The similarity of the rotation spectrum of caged water to water in the gas phase indicates that water is free to rotate in the C60 cage even at temperature as low as 3 K. However, spectral lines show a splitting of about 0.5 meV what is not compatible with the icosahedral symmetry of C60. Different models (e.g. crystal field effects in solid C60, C60 cage distortions) will be discussed. This work was supported by institutional research funding IUT23-3 of the Estonian Ministry of Education and Research.

  12. Calculations on the Nonlinear Second—Order Optical Polarizabilities for Series of Donor—C60 Molecules

    Institute of Scientific and Technical Information of China (English)

    刘孝娟; 封继康; 任爱民


    The equilibrium geometries and UV-visible spectra of a series of donor-C60 molecules were obtained by means of the AM1 and INDO/CI method,on the basis of accurate geometric and electronic structures.The nonlinear second-order optical polarizabilities were calculated using the method INDO/SDCI combined with the Sum-Over-States(SOS) expression.The calculatedβ(λ=1.34μm) values are 28.81,48.56,57.33,66.99,70.85,85.84,and 142.14(×10-30 esu) for the molecules A,B,C,D,E,F and G,respectively.The frontier orbitals were plot for the representative molecules in order to exhibit the intramolecular charge transfer.The results indicate the introduction of thienylethylene can enhance the NLO response and the dimethylaniline-substituted dithienyl-ethylene-C60 (molecule G) possesses the largest NLO second-order optical polarizability.The large β values can be attributed to the charge transfer between the substituents and C60,as well as within the three-dimensional conjugated sphere of C60.

  13. Size selective hydrophobic adsorbent for organic molecules (United States)

    Sharma, Pramod K. (Inventor); Hickey, Gregory S. (Inventor)


    The present invention relates to an adsorbent formed by the pyrolysis of a hydrophobic silica with a pore size greater than 5 .ANG., such as SILICALITE.TM., with a molecular sieving polymer precursor such as polyfurfuryl alcohol, polyacrylonitrile, polyvinylidene chloride, phenol-formaldehyde resin, polyvinylidene difluoride and mixtures thereof. Polyfurfuryl alcohol is the most preferred. The adsorbent produced by the pyrolysis has a silicon to carbon mole ratio of between about 10:1 and 1:3, and preferably about 2:1 to 1:2, most preferably 1:1. The pyrolysis is performed as a ramped temperature program between about and C., and preferably between about and C. The present invention also relates to a method for selectively adsorbing organic molecules having a molecular size (mean molecular diameter) of between about 3 and 6 .ANG. comprising contacting a vapor containing the small organic molecules to be adsorbed with the adsorbent composition of the present invention.

  14. Atom-Specific Identification of Adsorbed Chiral Molecules by Photoemission (United States)

    Kim, J. W.; Carbone, M.; Dil, J. H.; Tallarida, M.; Flammini, R.; Casaletto, M. P.; Horn, K.; Piancastelli, M. N.


    The study of chiral adsorbed molecules is important for an analysis of enantioselectivity in heterogeneous catalysis. Here we show that such molecules can be identified through circular dichroism in core-level photoemission arising from the chiral carbon atoms in stereoisomers of 2,3-butanediol molecules adsorbed on Si(100), using circularly polarized x rays. The asymmetry in the carbon 1s intensity excited by right and left circularly polarized light is readily observed, and changes sign with the helicity of the radiation or handedness of the enantiomers; it is absent in the achiral form of the molecule. This observation demonstrates the possibility of determining molecular chirality in the adsorbed phase.

  15. Effect of heating of the electronic subsystem on the thermal stability of the C-60 and C-20 fullerenes and (C-20)(2) cluster molecule

    NARCIS (Netherlands)

    Davydov, I. V.


    The effect of heating of the electronic subsystem on the thermal stability of C-60 and C-20 fullerenes and a (C-20)(2) cluster molecule is investigated theoretically. It is demonstrated that the excitation of electrons to upper energy levels in accordance with the Fermi-Dirac distribution function d

  16. Chiral switching by spontaneous conformational change in adsorbed organic molecules. (United States)

    Weigelt, Sigrid; Busse, Carsten; Petersen, Lars; Rauls, Eva; Hammer, Bjørk; Gothelf, Kurt V; Besenbacher, Flemming; Linderoth, Trolle R


    Self-assembly of adsorbed organic molecules is a promising route towards functional surface nano-architectures, and our understanding of associated dynamic processes has been significantly advanced by several scanning tunnelling microscopy (STM) investigations. Intramolecular degrees of freedom are widely accepted to influence ordering of complex adsorbates, but although molecular conformation has been identified and even manipulated by STM, the detailed dynamics of spontaneous conformational change in adsorbed molecules has hitherto not been addressed. Molecular surface structures often show important stereochemical effects as, aside from truly chiral molecules, a large class of so-called prochiral molecules become chiral once confined on a surface with an associated loss of symmetry. Here, we investigate a model system in which adsorbed molecules surprisingly switch between enantiomeric forms as they undergo thermally induced conformational changes. The associated kinetic parameters are quantified from time-resolved STM data whereas mechanistic insight is obtained from theoretical modelling. The chiral switching is demonstrated to enable an efficient channel towards formation of extended homochiral surface domains. Our results imply that appropriate prochiral molecules may be induced (for example, by seeding) to assume only one enantiomeric form in surface assemblies, which is of relevance for chiral amplification and asymmetric heterogenous catalysis.

  17. Self-Assembly of Individually Addressable Complexes of C-60 and Phthalocyanines on a Metal Surface : Structural and Electronic Investigations

    NARCIS (Netherlands)

    Samuely, Tomas; Liu, Shi-Xia; Haas, Marco; Decurtins, Silvio; Jung, Thomas A.; Stoehr, Meike


    The hosting properties of a close-packed layer of phenoxy-substituted phthalocyanine derivatives adsorbed on Ag(III) were investigated for the adsorption of C-60 molecules. The C-60 molecules bind to two clearly distinguishable sites, namely, to the underlying metal substrate in between two adjacent

  18. Hydrogen molecule on lithium adsorbed graphene: A DFT study (United States)

    Kaur, Gagandeep; Gupta, Shuchi; Gaganpreet, Dharamvir, Keya


    Electronic structure calculations for the adsorption of molecular hydrogen on lithium (Li) decorated and pristine graphene have been studied systematically using SIESTA code [1] within the framework of the first-principle DFT under the Perdew-Burke-Ernzerhof (PBE) form of the generalized gradient approximation (GGA)[2], including spin polarization. The energy of adsorption of hydrogen molecule on graphene is always enhanced by the presence of co-adsorbed lithium. The most efficient adsorption configuration is when H2 is lying parallel to lithium adsorbed graphene which is in contrast to its adsorption on pristine graphene (PG) where it prefers perpendicular orientation.

  19. Dynamics of different molecules adsorbed in porous media

    Indian Academy of Sciences (India)

    S Mitra; V S Kamble; A K Tripathi; N M Gupta; R Mukhopadhyay


    We present in this paper a comparative study on the dynamics of benzene, cyclohexane, and methanol molecules, confined in the pores of MCM-41 molecular sieve and HZSM-5 zeolite. The quasi-elastic neutron scattering (QENS) measurements revealed that the physical state of these adsorbed molecules depended not only on the structural characteristics of the host matrix but also on the chemical properties, such as dipole moment, of the guest molecules. Thus, while no motion was observed in the time-scale of 10−10 –10−12 s in the case of methanol, the larger size benzene and cyclohexane molecules are found to perform six-fold and three-fold jump rotation, respectively, when adsorbed inside the cages of HZSM-5 at room temperature. At the same time, all the three molecules are found to undergo a translational motion inside the pores of MCM-41 molecular sieves, the value of diffusion constant being the lowest in case of methanol because of its higher polarity. Translationl motion of the guest molecules inside the pores of MCM-41 can be satisfactorily described by Chudley–Eliott fixed jump length diffusion and accordingly the residence time, jump length and diffusion constant are estimated.

  20. What is C60. C60 no shotai wa

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, E. (Toyohashi University of Technology, Aichi (Japan))


    This paper elucidates what C60 really is. C60(1) is a carbon cluster of a special structure with Cs bonded solidly, and is a molecule chemically. Sixty Sp[sup 2] mixed carbon atoms are distributed evenly on a sphere with a radius of 7[angstrom]. Molecules in a crystal are of nearly perfect sphere, with small inter-molecular contact and weak binding force, and spinning at more than one billion rotations per second. C60 is a carbon's fourth allotrope. Three types of modification have been known to date, including the rugby ball shaped fullerene. Fullerene has been studied actively resulting in successive new reports. It is manufactured basically using the Kraetchmer's resistive heating method at a yield of approximately 10%. A plasma discharge process and an improved laser irradiation process can raise the yield to as high as 20% or more. Industrial application of C60 is within reach. Developmental researches are being moved forward by private corporations in Japan. Its application may cover wide areas, including electric conductors, semiconductors and the like. Elucidation of its production mechanisms has been waited for, together with solving a problem of reducing C60 reagent price. 45 refs., 3 figs.

  1. Porous polymer monoliths functionalized through copolymerization of a C60 fullerene-containing methacrylate monomer for highly efficient separations of small molecules

    KAUST Repository

    Chambers, Stuart D.


    Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) and poly(butyl methacrylate-co-ethylene dimethacrylate) capillary columns, which incorporate the new monomer [6,6]-phenyl-C 61-butyric acid 2-hydroxyethyl methacrylate ester, have been prepared and their chromatographic performance have been tested for the separation of small molecules in the reversed phase. While addition of the C60-fullerene monomer to the glycidyl methacrylate-based monolith enhanced column efficiency 18-fold, to 85 000 plates/m at a linear velocity of 0.46 mm/s and a retention factor of 2.6, when compared to the parent monolith, the use of butyl methacrylate together with the carbon nanostructured monomer afforded monolithic columns with an efficiency for benzene exceeding 110 000 plates/m at a linear velocity of 0.32 mm/s and a retention factor of 4.2. This high efficiency is unprecedented for separations using porous polymer monoliths operating in an isocratic mode. Optimization of the chromatographic parameters affords near baseline separation of 6 alkylbenzenes in 3 min with an efficiency of 64 000 plates/m. The presence of 1 wt % or more of water in the polymerization mixture has a large effect on both the formation and reproducibility of the monoliths. Other factors such as nitrogen exposure, polymerization conditions, capillary filling method, and sonication parameters were all found to be important in producing highly efficient and reproducible monoliths. © 2011 American Chemical Society.

  2. Raman Laser Polymerization of C60 Nanowhiskers

    Directory of Open Access Journals (Sweden)

    Ryoei Kato


    Full Text Available Photopolymerization of C60 nanowhiskers (C60NWs was investigated by using a Raman spectrometer in air at room temperature, since the polymerized C60NWs are expected to exhibit a high mechanical strength and a thermal stability. Short C60NWs with a mean length of 4.4 μm were synthesized by LLIP method (liquid-liquid interfacial precipitation method. The Ag(2 peak of C60NWs shifted to the lower wavenumbers with increasing the laser beam energy dose, and an energy dose more than about 1520 J/mm2 was found necessary to obtain the photopolymerized C60NWs. However, excessive energy doses at high-power densities increased the sample temperature and lead to the thermal decomposition of polymerized C60 molecules.

  3. Translocation mechanism of C60 and C60 derivations across a cell membrane (United States)

    Liang, Lijun; Kang, Zhengzhong; Shen, Jia-Wei


    Carbon-based nanoparticles (NPs) such as fullerenes and nanotubes have been extensively studied for drug delivery in recent years. The permeation process of fullerene and its derivative molecules through membrane is essential to the utilization of fullerene-based drug delivery system, but the mechanism and the dynamics of permeation through cell membrane are still unclear. In this study, coarse-grained molecular dynamics simulations were performed to investigate the permeation process of functionalized fullerene molecules (ca. 0.72 nm) through the membrane. Our results show that single functionalized fullerene molecule in such nanoscale could permeate the lipid membrane in micro-second time scale. Pristine C60 molecules prefer to aggregate into several small clusters while C60OH15 molecules could aggregate into one big cluster to permeate through the lipid membrane. After permeation of C60 or its derivatives into membrane, all C60 and C60OH15 molecules disaggregated and monodispersed in the lipid membrane.

  4. Distribution of adsorbed molecules in electronic nose sensors

    DEFF Research Database (Denmark)

    Swann, M.J.; Glidle, A.; Gadegaard, Nikolaj


    Neutron reflectivity measurements of thin films of electropolymerised poly(pyrrole) show that swelling of these insoluble polymers does occur following vapour adsorption. The variation in swelling found for different vapours is correlated with corresponding changes in polymer conductivity and mas...... of adsorbed vapour. This correlation suggests that hydrophobic and hydrophilic vapour species adsorb into regions of the membrane with different solvating environments (C) 2000 Elsevier Science B.V. All rights reserved....

  5. On the fluorescence of C60 at room temperature

    Institute of Scientific and Technical Information of China (English)


    The fluorescence properties of C 60 in different organic solvents have been investigated at room temperature. Three fluorescence emission centers are discovered and ascribed to different aggregations of C 60 in solvent. A series of blue fluorescence peaks centered at 440 nm derive from C 60 nanoparticles; a distinctive yellow-green fluorescence band in 575 nm region arises from the aggregates of C 60 nanoparticles; a more informative salmon fluorescence band around 700 nm originates from C 60 microcrystals. And the distinct configurations of C 60 aggregations are closely associated with the characteristic interaction between C 60 and solvent molecules.

  6. Synthesis, Crystal Structure and Characterization of a Novel Super Molecule [Na(C60H80O12)]+[Au(SCN)4]%金(Ⅲ)与杯[4]乙酯合钠(Ⅰ)超分子化合物:[Na(C60H80O12)]+[Au(SCN)4]-的合成、结构及性能

    Institute of Scientific and Technical Information of China (English)

    付勇; 徐琰; 宋毛平; 吴养洁


    A novel super molecule [Na(C60H80O12)]+[Au(SCN)4]- was obtained by extraction of calix[4] arene (L) for an aqueous solution containing [AuCl4]-, and NaCl into CH2Cl2. The crystal structure and properties of the title super molecule were characterized by single-crystal X-ray diffraction, IR and 1H NMR spectra. The X-ray single crystal structure analysis shows that the crystal was Tetragonal system with space group P4/n and the unit cell parameters were as follows: a=2.880 8(18) nm, b=2.880 8(18) nm, c=2.2924(5) nm, and final R indices [I>2σ(I)]:R1=0.0485, wR2=0.1061. CCDC: 243229.

  7. C$_{60}$ in Photodissociation Regions

    CERN Document Server

    Castellanos, Pablo; Sheffer, Yaron; Wolfire, Mark G; Tielens, Alexander G G M


    Recent studies have confirmed the presence of buckminsterfullerene (C$_{60}$) in different interstellar and circumstellar environments. However, several aspects regarding C$_{60}$ in space are not well understood yet, such as the formation and excitation processes, and the connection between C$_{60}$ and other carbonaceous compounds in the interstellar medium, in particular polycyclic aromatic hydrocarbons (PAHs). In this paper we study several photodissociation regions (PDRs) where C$_{60}$ and PAHs are detected and the local physical conditions are reasonably well constrained, to provide observational insights into these questions. C$_{60}$ is found to emit in PDRs where the dust is cool ($T_d = 20-40$ K) and even in PDRs with cool stars. These results exclude the possibility for C$_{60}$ to be locked in grains at thermal equilibrium in these environments. We observe that PAH and C$_{60}$ emission are spatially uncorrelated and that C$_{60}$ is present in PDRs where the physical conditions (in terms of radi...

  8. Solubility Characteristics of PCBM and C60. (United States)

    Boucher, David; Howell, Jason


    Empirical data indicate that several good solvents for C60 and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have substantial polar and hydrogen-bonding components, which are not intrinsic to the structure of the C60 and PCBM molecules themselves. Functional solubility parameter (FSP) and convex solubility parameter (CSP) computations are performed on C60 and PCBM using solubility data available in the literature. The CSP and FSP results are compared to previously reported Hansen solubility parameters (HSPs) and to the parameters calculated using additive functional group contribution methods. The CSP and FSP methods confirm the anomalously large polar and hydrogen-bonding parameters, δP and δH, obtained experimentally for C60 and PCBM. This behavior, which is quite irregular given the structure of the molecules, is due to the fact that several good solvents have high δP and δH values. Thus, these irregularities are highlighted by the CSP and FSP calculations. Additional contradictory solubility characteristics are disclosed by comparing the experimental solubility parameters to a linear solvation energy relationship (LSER) model, additive functional group calculations, and COSMO-RS computations. The FSP solubility function strongly suggests that the solubility parameters do not accurately represent the cohesive energy density properties of C60 and PCBM, as intended, but rather they manifest the properties of the solvents, e.g., high δP and δH values, that are necessary to accommodate these molecules in the liquid phase.

  9. Detection of Ordered Molecules Adsorbed on Graphene: a Theoretical Study (United States)

    Wang, Yong; Zhang, Xue-Qing; Li, Hui


    Graphene has been demonstrated to be able to detect individual gas molecules [Schedin et al. Nat. Mater. 6 (2007) 652], which has attracted a lot of sensor research activities. Here we report for the first time that graphene is capable of detecting the ordering degree of absorbed water molecules. The efficiency of doping varies from the degrees of molecular ordering. The simulated results show that the highly ordered water molecules contribute more to the doping effect, which reduces the conductance of the water/graphene system.

  10. Substrate-mediated interactions and intermolecular forces between molecules adsorbed on surfaces. (United States)

    Sykes, E Charles H; Han, Patrick; Kandel, S Alex; Kelly, Kevin F; McCarty, Gregory S; Weiss, Paul S


    Adsorbate interactions and reactions on metal surfaces have been investigated using scanning tunneling microscopy. The manners in which adsorbates perturb the surface electronic structure in their vicinity are discussed. The effects these perturbations have on other molecules are shown to be important in overlayer growth. Interactions of molecules with surface steps are addressed, and each molecule's electron affinity is shown to dictate its adsorption sites at step edges. Standing waves emanating from steps are demonstrated to effect transient molecular adsorption up to 40 A away from the step edge. Halobenzene derivatives are used to demonstrate how the surface is important in aligning reactive intermediates.

  11. Laser electrospray mass spectrometry of adsorbed molecules at atmospheric pressure (United States)

    Brady, John J.; Judge, Elizabeth J.; Simon, Kuriakose; Levis, Robert J.


    Atmospheric pressure mass analysis of solid phase biomolecules is performed using laser electrospray mass spectrometry (LEMS). A non-resonant femtosecond duration laser pulse vaporizes native samples at atmospheric pressure for subsequent electrospray ionization and transfer into a mass spectrometer. LEMS was used to detect a complex molecule (irinotecan HCl), a complex mixture (cold medicine formulation with active ingredients: acetaminophen, dextromethorphan HBr and doxylamine succinate), and a biological building block (deoxyguanosine) deposited on steel surfaces without a matrix molecule.

  12. Surface Modification through Chemically Adsorbed Monolayer of Thiophene Molecules (United States)

    Yamamoto, Shin-ichi; Ogawa, Kazufumi


    Using a time-averaged dielectrophoretic force from an applied electric field, we have observed the assembly of a chemically adsorbed monomolecular layer (CAM) on microwires and connections and the formation of an electric path between a lithographically patterned array of two platinum (Pt) electrodes. A Pt electrode/monolayer/Pt electrode junction was fabricated by the self-assembly of a rigid monomolecular layer, namely 3-{6-[11-(trichlorosilyl)undecanoyl]hexyl} thiophene (TEN) with thiophene groups in the lateral direction between the Pt electrodes. Conductive probe AFM (CP-AFM) was used to investigate the forward bias conduction properties of a TEN film grown by a wet deposition process on a glass substrate. The self-assembly depends on the ideal rigidity of the CAM and the strong affinity of the thiophene end groups of the CAM for the Pt electrode. The current-voltage (I-V) characteristics of the conjugated thiophene junction exhibited stepwise features at room temperature. The I-V characteristics can be explained by electron transport through the junction. From the results of experiments carried out under ambient conditions, the conductivity of the laterally conjugated polythiophene groups was calculated to be 5.0 ×104 S/cm. Understanding and using these effects will allow the controlled fabrication and positioning of microwires or connections at densities much greater than those now achievable.

  13. Local field distribution and configuration of CO molecules adsorbed on the nanostructure platinum surface

    Institute of Scientific and Technical Information of China (English)

    Huang Xiao-Jing; He Su-Zhen; Wu Chen-Xu


    This paper shows that the local electric field distribution near the nanostructure metallic surface is obtained by solving the Laplace equation, and furthermore, the configuration of CO molecules adsorbed on a Pt nanoparticle surface is obtained by using Monte Carlo simulation. It is found that the uneven local electric field distribution induced by the nanostructure surface can influence the configuration of carbon monoxide (CO) molecules by a force, which drags the adsorbates to the poles of the nanoparticles. This result, together with our results obtained before, may explain the experimental results that the nanostructure metallic surface can lead to abnormal phenomena such as anti-absorption infrared effects.

  14. An ab initio study of the field-induced position change of a C60 molecule adsorbed on a gold tip

    DEFF Research Database (Denmark)

    Stadler, Robert; Kubatkin, S.; Bjørnholm, Thomas


    be based on such junctions if the mechanism of the process is understood. We present density functional theory based plane wave calculations, where we studied the energetics of the molecule’s adsorption under the influence of an external field. Particular emphasis was placed on investigating a possible...

  15. Local electric field and configuration of CO molecules adsorbed on a nanostructured surface with nanocones

    Institute of Scientific and Technical Information of China (English)

    You Rong-Yi; Huang Xiao-Jing


    Based on the nanostructured surface model that the (platinum,Pt) nanocones grow out symmetrically from a plane substrate,the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results,the adsorbed CO molecules are modelled as dipoles,and three kinds of interactions,I.e. Interactions between dipoles and local electric field,between dipoles and dipoles,as well as between dipoles and nanostructured substrate,are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field,and this agglomeration becomes more compact with decreasing conical angle,which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE),which was found when CO molecules were adsorbed on the nancetructured transition-metal surface.

  16. Mechanism of melting in submonolayer films of nitrogen molecules adsorbed on the basal planes of graphite

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Bruch, Ludwig Walter; Taub, H.


    The melting mechanism in submonolayer films of N-2 molecules adsorbed on the basal planes of graphite is studied using molecular-dynamics simulations. The melting is strongly correlated with the formation of vacancies in the films. As the temperature increases, the edges of the submonolayer patch...

  17. Ionization energies of the C60 fullerene and its hydrogenated derivatives C60H18 and C60H36 determined by electron ionization (United States)

    Pogulay, Andrey V.; Abzalimov, Rinat R.; Nasibullaev, Shamil'k.; Lobach, Anatoly S.; Drewello, Thomas; Vasil'Ev, Yury V.


    Modification of a method for processing positive ion ionization efficiency curves of polyatomic molecules, as developed earlier by Märk and coworkers, has been described. Based on the method, the first, second, and third ionization energies of C60 have been re-examined and found to be in excellent agreement with the most reliable literature data. The ionization energies for C60H18 and C60H36 have been measured for the first time and were established as 7.3+/-0.3 eV and 7.01+/-0.25 eV, respectively. Although the appearance energy of C60H362+ (18.7+/-0.2 eV) has been determined to be lower than that of C602+ (18.98+/-0.35 eV), the reverse scenario is true for the second ionization energies of C60H36 and C60.

  18. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    Directory of Open Access Journals (Sweden)

    Makoto Ishikawa


    Full Text Available We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C60 molecules into the graphite. Moreover, it is found that the intercalated C60 molecules can rotate in between single graphene sheets by using C13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  19. Mapping spin distributions in electron acceptor molecules adsorbed on nanostructured graphene by the Kondo effect (United States)

    Garnica, Manuela; Calleja, Fabián; Vázquez de Parga, Amadeo L.; Miranda, Rodolfo


    Electron acceptor molecules adsorbed on nanostructured graphene grown on Ru(0001) were investigated by low temperature scanning tunneling microscopy and spectroscopy (LT-STM/STS). Our experiments reveal a considerable charge transfer from the substrate to the single molecules leading to the partial occupation of the LUMO of the neutral molecules. The nanostructured graphene modulates the hybridization between the transferred unpaired electron and the ruthenium conduction electrons leading to the appearance of a Kondo effect. Spatially resolved LT-STS allows the high resolution mapping of the spin distribution of the charge transferred and a characteristic inelastic Kondo features associated to specific vibrational modes.

  20. Infrared spectroscopy of fullerene C60/anthracene adducts

    CERN Document Server

    Garcia-Hernandez, D A; Manchado, A


    Recent Spitzer Space Telescope observations of several astrophysical environments such as Planetary Nebulae, Reflection Nebulae, and R Coronae Borealis stars show the simultaneous presence of mid-infrared features attributed to neutral fullerene molecules (i.e., C60) and polycyclic aromatic hydrocarbons (PAHs). If C60 fullerenes and PAHs coexist in fullerene-rich space environments, then C60 may easily form adducts with a number of different PAH molecules; at least with catacondensed PAHs. Here we present the laboratory infrared spectra (~2-25 um) of C60 fullerene and anthracene Dies-Alder mono- and bis-adducts as produced by sonochemical synthesis. We find that C60/anthracene Diels-Alder adducts display spectral features strikingly similar to those from C60 (and C70) fullerenes and other unidentified infrared emission features. Thus, fullerene-adducts - if formed under astrophysical conditions and stable/abundant enough - may contribute to the infrared emission features observed in fullerene-containing circu...

  1. Fragmentation of the C60 molecule in collision with light ions studied by a multi-correlation technique. Cross-sections, electron spectroscopy; Fragmentation de la molecule C60 par impact d'ions legers etudiee en multicorrelation. Sections efficaces, spectroscopie d'electrons

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A


    A quantitative study of the C60 fullerenes fragmentation in collision with light ions (H{sub n}{sup +} with n=1,2,3, He{sup q+} with q=1,2) in the velocity range 0,1 - 2,3 u.a.) is presented. The multi-correlation technique, developed between fragment ions and electrons with well defined energy, has enlightened some of the dependences and properties of fragmentation mechanisms (cross sections, electron spectroscopy, size distributions, kinetic energy of fragment ions, Campi's scatter plot, activation energies). The deposited energy hence appeared as an important parameter. Cross sections have been measured, for the first time, for all the collisional processes. Ionisation and capture only depends on the collision velocity. On the other hand, scaling laws with the deposited energy have been observed for the cross sections of multifragmentation, which depends on the collision energy and the nature of the projectile. The deposited energy has also been found as an essential parameter to understand the evolution of the charged fragment size distributions. The electron spectroscopy, achieved at an emission angle of 35 degrees, showed spectra peaked at important energies (from 5 to 20 eV). The spectra shape depends on the collision velocity. A first theoretical analysis points out the link between the observed energy distribution and the presence of a centrifugal potential barrier. Finally, correlation experiments between produced ions and electron energy reveal that electron energy increases with internal energy. (author)

  2. Photophysics of C60 Colloids (United States)


    34Investigation of encapsulation and solvatochromism of fullerenes in binary solvent mixtures," Journal of Physical Chemistry B 103(51), 11256-11260 (1999). 76...E. Huie, P. Neta, H. Hungerbühler, and K.-D. Asmus, "Excitation of C60, solubilized in water by triton X-100 and [gamma]- cyclodextrin , and

  3. C60 1,1,2,2-tetrachloroethylene tetrasolvate

    Directory of Open Access Journals (Sweden)

    C. Arunkumar


    Full Text Available In the title complex, C60·4C2Cl4, the C60 molecule is located on an inversion centre and there are two tetrachloroethylene (TCE molecules in the asymmetric unit. Both TCE molecules show positional disorder, with occupancy ratios of 0.75:0.25 and 0.56:0.44. Four fullerene C atoms form short contacts [3.208 (17 and 3.223 (17 Å] with the centres of the TCE double bonds, indicating that C60–solvent interactions are largely π–π in nature.

  4. Sc20C60: a volleyballene (United States)

    Wang, Jing; Ma, Hong-Man; Liu, Ying


    An exceptionally stable hollow cage containing 20 scandium atoms and 60 carbon atoms has been identified. This Sc20C60 molecular cluster has a Th point group symmetry and a volleyball-like shape that we refer to below as ``Volleyballene''. Electronic structure analysis shows that the formation of delocalized π bonds between Sc atoms and the neighboring pentagonal rings made of carbon atoms is crucial for stabilizing the cage structure. A relatively large HOMO-LUMO gap (~1.4 eV) was found. The results of vibrational frequency analysis and molecular dynamics simulations both demonstrate that this Volleyballene molecule is exceptionally stable.An exceptionally stable hollow cage containing 20 scandium atoms and 60 carbon atoms has been identified. This Sc20C60 molecular cluster has a Th point group symmetry and a volleyball-like shape that we refer to below as ``Volleyballene''. Electronic structure analysis shows that the formation of delocalized π bonds between Sc atoms and the neighboring pentagonal rings made of carbon atoms is crucial for stabilizing the cage structure. A relatively large HOMO-LUMO gap (~1.4 eV) was found. The results of vibrational frequency analysis and molecular dynamics simulations both demonstrate that this Volleyballene molecule is exceptionally stable. Electronic supplementary information (ESI) available: Sc20C60: a Volleyballene_SI. See DOI: 10.1039/c5nr07784b

  5. Adlayers of C60-C60 and C60-C70 fullerene dimers formed on au(111) in benzene solutions studied by STM and LEED. (United States)

    Matsumoto, Masashi; Inukai, Junji; Tsutsumi, Eishi; Yoshimoto, Soichiro; Itaya, Kingo; Ito, Osamu; Fujiwara, Koichi; Murata, Michihisa; Murata, Yasujiro; Komatsu, Koichi


    Scanning tunneling microscopy (STM) and low-energy electron diffraction were used to reveal the structures of ordered adlayers of [2+2]-type C60-C60 fullerene dimer (C120) and C60-C70 cross-dimer (C130) formed on Au(111) by immersingit in abenzene solution containing C120 or C130 molecules. High-resolution STM images clearly showed the packing arrangements and the electronic structures of C120 and C130 on the Au(111) surface in ultrahigh vacuum. The (2 square root3 x 4square root3)R30 degrees, (2square root3 x 5square root3)R30 degrees, and (7 x 7) structures were found for the C120 adlayer on the Au(111) surface, whereas C130 molecules were closely packed on the surface. Each C60 or C70 monomer cage was discerned in the STM image of a C130 molecule.

  6. Laser-assisted deposition of thin C60 films

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Fæster, Søren

    . However, organic materials are usually not well suited for direct laser irradiation, since the organic molecules may suffer from fragmentation by the laser light. We have, therefore, explored the possible fragmentation of organic molecules by attempting to produce thin films of C60 which is a strongly...... bound carbon molecule with a well-defined mass (M = 720 amu) and therefore a good, organic test molecule. C60 fullerene thin films of average thickness of more than 100 nm was produced in vacuum by matrix-assisted pulsed laser evaporation (MAPLE). A 355 nm Nd:YAG laser was directed onto a frozen target...... of the matrix material, anisole, with a concentration of 0.67 wt% C60. At laser fluences below 1.5 J/cm2, a dominant fraction of the film molecules are C60 transferred to the substrate without any fragmentation. High-resolution SEM images of MAPLE deposited films reveal large circular features on the surface...

  7. Study of Conformation and Dynamics of Molecules Adsorbed in Zeolites by 1H NMR (United States)

    Michel, Dieter; Bohlmann, Winfried; Roland, Jorg; Mulla-Osman, Samir

    The chapter Study of Conformation and Dynamics of Molecules Adsorbed in Zeolites by 1H NMR is concerned with the application of high-resolution (HR) solid-state NMR techniques to study the behavior of molecules adsorbed on surfaces of nanoporous solids, such as zeolitic molecular sieves. This includes a combined or alternative application of conventional high-resolution NMR methods and of high-resolution solid-state NMR techniques, including magic-angle sample spinning (MAS), cross-polarization (CP), high-power decoupling and appropriate multiple-pulse sequences for two- or higher dimensional NMR and multiple-quantum spectroscopy. The interaction of adsorbed molecules with adsorption centers in the internal surfaces of porous solids does not only lead to changes in the reorientational and translational mobility of the molecular species but influences also the molecular conformation. Examples will be given for simple olefins in interaction with inner zeolite surfaces. Conclusions about the correlation times of the internal reorientational and translational dynamics are derived in complete agreement with the conclusion obtained from diffusion coefficients by means of PFG NMR (second chapter). Since the methodical approach of HR MAS NMR in heterogeneous systems presented here is also valuable for the investigation of lyotropic crystalline phases using HR MAS NMR (in Chap. 12) And for the NMR studies of cartilage (in Chap. 13) it was also the aim of this chapter to elucidate also the methodical background of these measurements in some more detail.

  8. STM studies of the epitaxial growth of C_(60) molecules on Si(111)-7 ×7 surface%C_(60)分子在Si(111)-7×7表面分子束外延生长的STM研究

    Institute of Scientific and Technical Information of China (English)

    赵明海; 孙静静; 王丹; 邹志强; 梁齐


    在超高真空中采用分子束外延(molecular beam epitaxial)技术进行C_(60)分子在硅(111)-7×7表面的生长,并利用扫描隧道显微镜进行原位研究.室温下,相对于无层错半胞(unfaulted half unit cell),C_(60)更易于吸附在有层错半胞(faulted half unit cell).表面台阶处的电子悬挂键密度最高,通过控制温度和时间进行退火处理后,C_(60)分子会向着台阶的方向扩散并聚集.测量分子在不同吸附位置的直径和高度,发现由于不同位置分子与衬底的相互作用强度的不同,其分子直径和高度也存在一定差异.还研究了C_(60)分子在Si(111)-7×7表面的多层生长模式,并且通过600℃退火处理在硅表面形成了有序的单层结构,从而实现了C_(60)分子在硅表面从Stanski-Krastanov三维岛状模式到Frank-van der Merwe层状生长模式的转变.

  9. Can circular dichroism in core-level photoemission provide a spectral fingerprint of adsorbed chiral molecules?

    Energy Technology Data Exchange (ETDEWEB)

    Allegretti, F [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Polcik, M [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); Sayago, D I [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); Demirors, F [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); O' Brien, S [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Nisbet, G [Centre for Applied Catalysis, Department of Chemical and Biological Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Lamont, C L A [Centre for Applied Catalysis, Department of Chemical and Biological Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Woodruff, D P [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom)


    The results of experimental measurements and theoretical simulations of circular dichroism in the angular distribution (CDAD) of photoemission from atomic core levels of each of the enantiomers of a chiral molecule, alanine, adsorbed on Cu(1 1 0) are presented. Measurements in, and out of, substrate mirror planes allow one to distinguish the CDAD due to the chirality of the sample from that due to a chiral experimental geometry. For these studies of oriented chiral molecules, the CDAD is seen not only in photoemission from the molecular chiral centre, but also from other atoms which have chiral geometries as a result of the adsorption. The magnitude of the CDAD due to the sample chirality differs for different adsorption phases of alanine, and for different emission angles and energies, but is generally small compared with CDAD out of the substrate mirror planes which is largely unrelated to the molecular chirality. While similar measurements of other molecules may reveal larger CDAD due to molecular chirality, the fact that the results for one chiral molecule show weak effects means that such CDAD is unlikely to provide a simple and routine general spectral fingerprint of adsorbed molecular chirality.

  10. Chemical effects on vibrational properties of adsorbed molecules on metal surfaces: Coverage dependence (United States)

    Ueba, H.


    Vibrational properties of chemisorbed molecules on metal surfaces are studied with a focus on the coverage dependent chemical shift of the frequencies. Available experimental data of a CO adsorption on transition metal and noble metal surfaces are analyzed in the light of the coverage dependent back-donation into the 2 π* orbitals of chemisorbed CO molecules. The vibrational frequency ωCO of the intramolecular stretching mode exhibits a downward shift of varying magnitude, depending on the amount of back-donation into the 2 π* orbitals of the chemisorbed CO. On increasing the coverage θ, ωCO usually increases due to the dipole-dipole interaction. On Cu surfaces, however, the shifts are relatively small, or in some cases, negative. So far, this anomalous frequency shift with θ is understood as a result of competitive effect between the upward dipole Ωdip and the downward chemical shift Ωchem associated with back-donation. The purpose of this paper is to establish the possible origin of the downward frequency shift through the electronic properties of an incomplete monolayer of adsorbates. The adsorbate density of states ρa is calculated by means of the coherent potential approximation, in which the electron hopping between the adsorbates (band formation effect) and the depolarization effect due to the proximity of ionized adsorbed molecules are taken into account. The change of the occupied portion of ρa and ρa ( ɛF) at the Fermi level ɛF with increasing θ then manifests itself in the coverage dependent Ωchem not only due to the static back-donation, but also due to the dynamical charge fluctuation during vibrational excitation. It is found that in a weakly chemisorbed system, such as CO/Cu, the negative Ωchem amounts to Ωdip at low θ. Consequently the apparent total frequency shift remains almost constant. As the coverage increases, Ωchem becomes larger than Ωdip due to the band effect. It is also shown that the variation of the back

  11. Large Relative Raman Shift for Molecules Adsorbed on Metallic Nano-particles

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Yun; XIA Yu-Xing; ZHAN Li; LENG Jiang-Hua


    The enhancement of two order-of-magnitudes is observed in surface-enhanced Raman spectroscopy (SERS) of gases (CO, C2H2, C2H4, etc) adsorbed on nitric acid-roughened metal foil. In addition, some Raman lines of gases adsorbed on these active substrates show larger frequency shifts and linewidth broadening, compared with the Raman spectroscopy of free gases. Using the two-oscillator electromagnetic model, we explain this phenomenon. It is related to the large non-regular particles on the active substrate we prepared. It is found that the parameters of the surface-plasmon dispersion, the distance of molecules from the surface and the radius of particles play crucial roles on the relative large Raman shifts.

  12. Evidence for photo-induced charge separation between dye molecules adsorbed to aluminium oxide surfaces. (United States)

    Cappel, Ute B; Moia, Davide; Bruno, Annalisa; Vaissier, Valerie; Haque, Saif A; Barnes, Piers R F


    Excited state dynamics and photo-induced charge transfer of dye molecules have been widely studied due to their relevance for organic and dye-sensitised solar cells. Herein, we present a femtosecond transient absorption spectroscopy study of the indolene dye D131 when adsorbed to inert Al2O3 substrates for different surface concentration of the dye. Surprisingly, we find that at high surface concentrations, the first singlet excited state of the dye is converted into a new state with an efficiency of about 80%. We assign the absorption features of this state to the oxidised dye and discuss the possibility of photo-induced charge separation between neighboring dye molecules. Our study is the first to show that this process can be highly efficient without the use of donor and acceptor molecules of different chemical structures.

  13. Structure formation in adsorbed overlayers comprising functional cross-shaped molecules: A Monte Carlo study (United States)

    Kasperski, Adam; Nieckarz, Damian; Szabelski, Paweł


    Surface confined self-assembly of functional star-shaped organic molecules is a promising method to create nanoporous networks with tailorable structure and functions. In this work we use the Monte Carlo simulation method to demonstrate how the morphology of these supramolecular assemblies can be tuned by manipulating intrinsic parameters of the building blocks and modified by the presence of co-adsorbed metal atoms. To that purpose we study the 2D self-assembly of planar cruciform molecules modeled as collections of interconnected segments, some of which were activated to represent discrete interaction centers. We consider a few exemplary adsorbed systems in which the molecules with different size, aspect ratio and intramolecular distribution of active centers form superstructures stabilized by short-range segment-segment interactions or by metal-segment interactions. These two situations correspond to supramolecular assemblies sustained by, for example, hydrogen bonding and metal-organic ligand coordination, respectively. The simulated results show that proper encoding of intramolecular interactions into the cruciform building bricks allows for directing the self-assembly towards largely diversified structures ranging from nanoclusters to porous grids. The obtained findings can facilitate designing and optimization of molecular networks comprising cross-shaped units including functionalized porphyrins and phthalocyanines and they can be helpful in preliminary selection of these building blocks.

  14. Formaldehyde molecule adsorbed on doped graphene: A first-principles study (United States)

    Liu, Xu-Ying; Zhang, Jian-Min


    Adsorption of formaldehyde (H2CO) on B-, N-, Si-, Al-, Cr-, Mn-, and Au-doped graphene was theoretically studied using first-principles approach based on density functional theory in order to exploit their potential applications as H2CO gas sensors. The electronic and magnetic properties of the graphene-molecule adsorption adducts are strongly dependent on the dopants. H2CO molecule is adsorbed weakly on B- and N-doped graphene; in general, strong chemisorption is observed on Si-, Al-, Cr-, Mn-, and Au-doped graphene. The most stable adsorption geometries, adsorption energies, magnetic moments, charge transfers, and density of states of these systems are thoroughly discussed. This work reveals that the sensitivity of graphene-based chemical gas sensors for H2CO can be drastically improved by introducing appropriate dopant. Al and Mn are found to be the best choices among all the dopants.

  15. Formaldehyde molecule adsorbed on doped graphene: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xu-Ying; Zhang, Jian-Min, E-mail:


    Adsorption of formaldehyde (H{sub 2}CO) on B-, N-, Si-, Al-, Cr-, Mn-, and Au-doped graphene was theoretically studied using first-principles approach based on density functional theory in order to exploit their potential applications as H{sub 2}CO gas sensors. The electronic and magnetic properties of the graphene-molecule adsorption adducts are strongly dependent on the dopants. H{sub 2}CO molecule is adsorbed weakly on B- and N-doped graphene; in general, strong chemisorption is observed on Si-, Al-, Cr-, Mn-, and Au-doped graphene. The most stable adsorption geometries, adsorption energies, magnetic moments, charge transfers, and density of states of these systems are thoroughly discussed. This work reveals that the sensitivity of graphene-based chemical gas sensors for H{sub 2}CO can be drastically improved by introducing appropriate dopant. Al and Mn are found to be the best choices among all the dopants.

  16. Molecular resonant dissociation of surface-adsorbed molecules by plasmonic nanoscissors (United States)

    Zhang, Zhenglong; Sheng, Shaoxiang; Zheng, Hairong; Xu, Hongxing; Sun, Mengtao


    The ability to break individual bonds or specific modes in chemical reactions is an ardently sought goal by chemists and physicists. While photochemistry based methodologies are very successful in controlling e.g. photocatalysis, photosynthesis and the degradation of plastic, it is hard to break individual molecular bonds for those molecules adsorbed on the surface because of the weak light-absorption in molecules and the redistribution of the resulting vibrational energy both inside the molecule and to its surrounding environment. Here we show how to overcome these obstacles with a plasmonic hot-electron mediated process and demonstrate a new method that allows the sensitive control of resonant dissociation of surface-adsorbed molecules by `plasmonic' scissors. To that end, we used a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) setup to dissociate resonantly excited NC2H6 fragments from Malachite green. The surface plasmons (SPs) excited at the sharp metal tip not only enhance the local electric field to harvest the light incident from the laser, but crucially supply `hot electrons' whose energy can be transferred to individual bonds. These processes are resonant Raman, which result in some active chemical bonds and then weaken these bonds, followed by dumping in lots of indiscriminant energy and breaking the weakest bond. The method allows for sensitive control of both the rate and probability of dissociation through their dependence on the density of hot electrons, which can be manipulated by tuning the laser intensity or tunneling current/bias voltage in the HV-TERS setup, respectively. The concepts of plasmonic scissors open up new versatile avenues for the deep understanding of in situ surface-catalyzed chemistry.The ability to break individual bonds or specific modes in chemical reactions is an ardently sought goal by chemists and physicists. While photochemistry based methodologies are very successful in controlling e.g. photocatalysis

  17. Magnetization switching in ferromagnets by adsorbed chiral molecules without current or external magnetic field. (United States)

    Ben Dor, Oren; Yochelis, Shira; Radko, Anna; Vankayala, Kiran; Capua, Eyal; Capua, Amir; Yang, See-Hun; Baczewski, Lech Tomasz; Parkin, Stuart Stephen Papworth; Naaman, Ron; Paltiel, Yossi


    Ferromagnets are commonly magnetized by either external magnetic fields or spin polarized currents. The manipulation of magnetization by spin-current occurs through the spin-transfer-torque effect, which is applied, for example, in modern magnetoresistive random access memory. However, the current density required for the spin-transfer torque is of the order of 1 × 10(6) A·cm(-2), or about 1 × 10(25) electrons s(-1) cm(-2). This relatively high current density significantly affects the devices' structure and performance. Here we demonstrate magnetization switching of ferromagnetic thin layers that is induced solely by adsorption of chiral molecules. In this case, about 10(13) electrons per cm(2) are sufficient to induce magnetization reversal. The direction of the magnetization depends on the handedness of the adsorbed chiral molecules. Local magnetization switching is achieved by adsorbing a chiral self-assembled molecular monolayer on a gold-coated ferromagnetic layer with perpendicular magnetic anisotropy. These results present a simple low-power magnetization mechanism when operating at ambient conditions.

  18. Magnetization switching in ferromagnets by adsorbed chiral molecules without current or external magnetic field (United States)

    Ben Dor, Oren; Yochelis, Shira; Radko, Anna; Vankayala, Kiran; Capua, Eyal; Capua, Amir; Yang, See-Hun; Baczewski, Lech Tomasz; Parkin, Stuart Stephen Papworth; Naaman, Ron; Paltiel, Yossi


    Ferromagnets are commonly magnetized by either external magnetic fields or spin polarized currents. The manipulation of magnetization by spin-current occurs through the spin-transfer-torque effect, which is applied, for example, in modern magnetoresistive random access memory. However, the current density required for the spin-transfer torque is of the order of 1 × 106 A·cm−2, or about 1 × 1025 electrons s−1 cm−2. This relatively high current density significantly affects the devices' structure and performance. Here we demonstrate magnetization switching of ferromagnetic thin layers that is induced solely by adsorption of chiral molecules. In this case, about 1013 electrons per cm2 are sufficient to induce magnetization reversal. The direction of the magnetization depends on the handedness of the adsorbed chiral molecules. Local magnetization switching is achieved by adsorbing a chiral self-assembled molecular monolayer on a gold-coated ferromagnetic layer with perpendicular magnetic anisotropy. These results present a simple low-power magnetization mechanism when operating at ambient conditions. PMID:28230054

  19. Adsorption of sodium and cesium on aggregates of C60 (United States)

    Harnisch, Martina; Daxner, Matthias; Scheier, Paul; Echt, Olof


    We explore the formation of C60 sodium and C60 cesium complexes in superfluid helium nanodroplets. Anomalies in mass spectra of these doped droplets reveal anomalies in the stability of ions. (C60) m Cs+ n ions ( m ≤ 6) are particularly abundant if they contain n = 6 m + 1 cesium atoms; (C60) m Cs2+ n dications ( m ≤ 3 or 5) are abundant if n = 6 m + 2. These findings are consistent with the notion that alkali metal atoms (A) transfer their valence electrons into the three-fold degenerate lowest unoccupied orbital of C60, resulting in particularly stable C60A6 building blocks. However, (C60) 4CsCs2+ n dications display an entirely different pattern; instead of an expected anomaly at n = 6 × 4 + 2 = 26 we observe a strong odd-even alternation starting at n = 6. Also surprising is the effect of adding one H2O or CO2 molecule to (C60) m Cs n mono- or dications; anomalies shift by two units as if the impurity were acting as an acceptor for two valence electrons from the alkali metal atoms.

  20. Charge transfer excitons in C60-dimers and polymers

    CERN Document Server

    Harigaya, K


    Charge-transfer (CT) exciton effects are investigated for the optical absorption spectra of crosslinked C60 systems by using the intermediate exciton theory. We consider the C60-dimers, and the two (and three) molecule systems of the C60-polymers. We use a tight-binding model with long-range Coulomb interactions among electrons, and the model is treated by the Hartree-Fock approximation followed by the single-excitation configuration interaction method. We discuss the variations in the optical spectra by changing the conjugation parameter between molecules. We find that the total CT-component increases in smaller conjugations, and saturates at the intermediate conjugations. It decreases in the large conjugations. We also find that the CT-components of the doped systems are smaller than those of the neutral systems, indicating that the electron-hole distance becomes shorter in the doped C60-polymers.

  1. The formation of buckminsterfullerene (C$_{60}$) in interstellar space

    CERN Document Server

    Berné, Olivier


    Buckminsterfullerene (C$_{60}$) was recently confirmed to be the largest molecule identified in space. However, it remains unclear how, and where this molecule is formed. It is generally believed that C$_{60}$ is formed from the build up of small carbonaceous compounds, in the hot and dense envelopes of evolved stars. Analyzing infrared observations, obtained by Spitzer and Herschel, we found that C$_{60}$ is efficiently formed in the tenuous and cold environment of an interstellar cloud illuminated by strong ultraviolet (UV) radiation fields. This implies that another formation pathway, efficient at low densities, must exist. Based on recent laboratory and theoretical studies, we argue that Polycyclic Aromatic Hydrocarbons are converted into graphene, and subsequently C$_{60}$, under UV irradiation from massive stars. This shows that alternative - top-down - routes are key to understanding the organic inventory in space.

  2. IR-REMPI spectroscopy for thermometry of C-60

    NARCIS (Netherlands)

    van Heijnsbergen, D.; von Helden, G.; Sartakov, B.; Meijer, G.


    Gas-phase C-60 molecules are excited with a 30 ps 266 nm Nd:YAG laser, followed by a train of high-power infrared (IR) sub-picosecond pulses from a free electron laser (FEL), which resonantly heats the molecules up to internal energies at which they efficiently undergo delayed ionization. By tuning

  3. Electrical conductivity of reconstructed Si(111) surface with sodium-doped C60 layers (United States)

    Tsukanov, D. A.; Ryzhkova, M. V.; Borisenko, E. A.; Zotov, A. V.; Saranin, A. A.


    Electrical conductance of sodium-doped C60 ultra-thin layers (1-6 monolayers) grown on the Na-adsorbed Si(111)√3 × √3-Au surface has been studied in situ by four-point probe technique, combined with low-energy electron diffraction observations. Evidence of conductance channel formation through the C60 ultrathin layer is demonstrated as a result of Na dosing of 3 and 6 monolayers thick C60 layers. The observed changes in surface conductivity can be attributed to the formation of fulleride-like NaC60 and Na2C60 compound layers.

  4. Scanning conductive probe microscopy of thiophen molecules incorporated into chemically adsorbed monolayer

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, S-I [Department of Electrical Engineering, Kobe City College of Technology, 8-3, Gakuenhigashi-machi, Nishi-ku, Kobe 651-2194 (Japan); Ogawa, K [Department of Advanced Materials Science, Faculty of Engineering, Kagawa University, 2217-20, Hayashi-cho, Takamatsu 761-0396 (Japan)], E-mail:


    We will describe a technique for acquiring the current-voltage characteristics of a metal-molecule-metal probe junction in the lateral direction using a conducting probe atomic force microscopy (CP-AFM) technique. To conduct a repetitive experiment efficiently, we have utilized the current imaging mode of the CP-AFM system. We have prepared a chemically adsorbed monolayer (CAM) of 3-{l_brace}6-{l_brace}11-(Trichlorosilyl)undecanoyl{r_brace}hexyl{r_brace} thiophene (TEN) on a glass substrate. The samples with the electric path were prepared by a chemical adsorption technique with TEN on a glass substrate, followed by an electro-oxidative polymerization with pure water. The conductivity of a polythiophene derivative monolayer was investigated for its application as a wire. The corresponding I-V curves have exhibited stability and are steep in current.

  5. Scanning conductive probe microscopy of thiophen molecules incorporated into chemically adsorbed monolayer (United States)

    Yamamoto, S.-I.; Ogawa, K.


    We will describe a technique for acquiring the current-voltage characteristics of a metal-molecule-metal probe junction in the lateral direction using a conducting probe atomic force microscopy (CP-AFM) technique. To conduct a repetitive experiment efficiently, we have utilized the current imaging mode of the CP-AFM system. We have prepared a chemically adsorbed monolayer (CAM) of 3-{6-{11-(Trichlorosilyl)undecanoyl}hexyl} thiophene (TEN) on a glass substrate. The samples with the electric path were prepared by a chemical adsorption technique with TEN on a glass substrate, followed by an electro-oxidative polymerization with pure water. The conductivity of a polythiophene derivative monolayer was investigated for its application as a wire. The corresponding I-V curves have exhibited stability and are steep in current.

  6. Adsorption and self-assembly of fullerenes on Si(111)√{ 3 } ×√{ 3 }-Ag: C60 versus C70 (United States)

    Olyanich, D. A.; Mararov, V. V.; Utas, T. V.; Zotov, A. V.; Saranin, A. A.


    Behavior of C60 and C70 fullerenes adsorbed onto Si(111)√{ 3 } ×√{ 3 }-Ag is compared on the basis of STM observations. Such characteristics as sticking coefficient, migration rate, attachment/detachment rate from the molecular islands are considered. Room-temperature sticking coefficient for C70 is slightly greater than that for C60. Due to their non-spherical shape, C70 are less mobile than spherical C60. For both types of fullerenes, mobility of molecules on the fullerene layer is significantly retarded as compared to that on bare Si(111)√{ 3 } ×√{ 3 }-Ag surface. Self-assembly of C60 obeys layer-by-layer growth mode, while C70 follows multi-layer mode, a sign of a greater Ehrlich-Schwoebel barrier. Alternating deposition of C60 and C70 paves the way to fabricate planar C60/C70 heterostructures with the most promising results being obtained with nanostructured islands grown on C60 monomolecular layer.

  7. Reducing HAuCl4 by the C60 dianion: C60-directed self-assembly of gold nanoparticles into novel fullerene bound gold nanoassemblies (United States)

    Liu, Wei; Gao, Xiang


    The C60 dianion is used to reduce tetrachloroauric acid (HAuCl4) for the first time; three-dimensional C60 bound gold (Au-C60) nanoclusters are obtained from C60-directed self-assembly of gold nanoparticles due to the strong affinities of Au-C60 and C60-C60. The process was monitored in situ by UV-vis-NIR spectroscopy. The resulting Au-C60 nanoclusters were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive spectroscopy (EDS), x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and FT-IR and Raman spectroscopies. TEM demonstrates the formation of 3D nanonetwork aggregates, which are composed of discrete gold nanocores covered with a C60 monolayer. The SAED and XRD patterns indicate that the gold nanocores inside the capped C60 molecules belong to the face-centred cubic crystal structure, while the C60 molecules are amorphous. The EDS and XPS measurements validate that the Au-C60 nanoclusters contain only Au and C elements and Au3+ is reduced to Au0. FT-IR spectroscopy shows the chemiadsorption of C60 to the gold nanocores, while Raman spectroscopy demonstrates the electron transfer from the gold nanocores to the chemiadsorbed C60 molecules. Au-C60 nanoclusters embedded in tetraoctyl-n-ammonium bromide (TOAB) on glassy carbon electrodes (GCEs) have been fabricated and have shown stable and well-defined electrochemical responses in aqueous solution.

  8. Structure and dynamics of monolayer films of squalane molecules adsorbed on a solid surface (United States)

    D. T Enevoldsen, A.; Hansen, F. Y.; Diama, A.; Taub, H.


    Squalane is a branched alkane (C_30H_62). It consists of a straight chain with 24 carbon atoms, as in tetracosane (C_24H_50), and has six methyl side groups. Branched polymers such as squalane are thought to be better lubricants than n-alkanes. At low temperature, our molecular dynamics (MD) simulations show that the molecules form an ordered monolayer which melts at approximately 325 K compared to the tetracosane monolayer melting point of ˜ 340 K. Our MD simulations indicate the same melting mechanism in the squalane monolayer that was found previously for tetracosane (F. Y. Hansen and H. Taub, Phys. Rev. Lett. 69, 652 (1992).) They also show that the adsorbed molecules are distorted from an all-trans carbon backbone in contrast to what was found for tetracosane. This may explain why the Bragg diffraction peaks were observed to be broader for the squalane monolayer than for tetracosane (D. Fuhrmann, A. P. Graham, L. Criswell, H. Mo, B. Matthies, K. W. Herwig, and H. Taub, Surf. Sci. 482-485, 77 (2001).). The diffusive motion in a squalane monolayer has been investigated by both quasielastic neutron scattering and MD simulations and compared to the dynamics in tetracosane monolayers. Focus will be on differences in the dynamics.

  9. Brownian dynamics simulation of peeling a strongly-adsorbed polymer molecule from a frictionless substrate. (United States)

    Iliafar, Sara; Vezenov, Dmitri; Jagota, Anand


    We used brownian dynamics to study the peeling of a polymer molecule, represented by a freely jointed chain, from a frictionless surface in an implicit solvent with parameters representative of single-stranded DNA adsorbed on graphite. For slow peeling rates, simulations match the predictions of an equilibrium statistical thermodynamic model. We show that deviations from equilibrium peeling forces are dominated by a combination of Stokes (viscous) drag forces acting on the desorbed section of the chain and a finite rate of hopping over a desorption barrier. Characteristic velocities separating equilibrium and nonequilibrium regimes are many orders of magnitude higher than values accessible in force spectroscopy experiments. Finite probe stiffness resulted in disappearance of force spikes due to desorption of individual links predicted by the statistical thermodynamic model under displacement control. Probe fluctuations also masked sharp transitions in peeling force between blocks of distinct sequences, indicating limitation in the ability of single-molecule force spectroscopy to distinguish small differences in homologous molecular structures.

  10. Electronic structure and binding geometry of tetraphenylporphyrin-derived molecules adsorbed on metal and metal oxide surfaces (United States)

    Coh, Senia

    Tetraphenylporphyrin (TPP)-derived molecules have been studied extensively as efficient photosensitizers when chemisorbed on the metal oxide substrates in dye-sensitized solar cells. Still, many fundamental electronic properties of the dye/oxide interface are not understood and need careful consideration. In this thesis we present a comprehensive study of the electronic structure, energy level alignment and the adsorption geometry of the TPP-derived dye molecules adsorbed on TiO2(110), ZnO(1120) and Ag(100) single crystal surfaces using ultra-high vacuum (UHV) based surface sensitive techniques. The alignment of the molecular energy levels with respect to the TiO 2 and ZnO band edges for all TPP-derived molecules we studied was found to be insensitive to either the nature of the functional groups located on the phenyl rings, presence of zinc as a central metal ion and different binding geometry of the molecules. Binding geometry, molecule-molecule interaction and the aggregation effects in the adsorbed layer, that were observed in the UV-visible spectra of the molecules adsorbed on ZnO substrate were not observed in the ultraviolet photoemission (UPS) and inverse photoemission (IPS) spectra of the occupied and unoccupied molecular states. Using near edge X-ray absorption fine structure (NEXAFS) and scanning tunneling microscopy (STM), binding geometry of the two representative TPP-derivatives was directly determined to be upright, with the porphyrin ring under large angle with respect to the surface for the p-ZnTCPP molecules and with the porphyrin ring parallel to the surface for the m-ZnTCPP molecules. We observe that the energies and the energy level alignment of the ZnTPP molecular levels measured in UPS and IPS depend on the substrate on which the molecules are adsorbed (Ag(100) or TiO2(110) single crystal surfaces). The differences are attributed to different charge screening properties of these two materials. Image charges created in the substrates during

  11. Semiconductor nanocrystals photosensitize C60 crystals. (United States)

    Biebersdorf, Andreas; Dietmüller, Roland; Susha, Andrei S; Rogach, Andrey L; Poznyak, Sergey K; Talapin, Dmitri V; Weller, Horst; Klar, Thomas A; Feldmann, Jochen


    Semiconductor nanocrystals (SCNCs) made of CdSe, CdTe, and InP are used to photosensitize needlelike C(60) crystals. The photocurrent is increased by up to 3 orders of magnitude as compared with C(60) crystals without SCNCs. The photocurrent spectrum can be tuned precisely by the SCNC size and material, rendering the SCNC-functionalized C(60) crystals an excellent material for spectrally tuneable photodetectors. We explain the increased photocurrent as a result of photoexcited electrons transferring from the SCNCs to the C(60) crystals and causing photoconductivity, while the complementary holes remain trapped in the SCNCs.

  12. Entrapping of exohedral metallofullerenes in carbon nanotubes: (CsC60)n@SWNT nano-peapods. (United States)

    Sun, Bao-Yun; Sato, Yuta; Suenaga, Kazutomo; Okazaki, Toshiya; Kishi, Naoki; Sugai, Toshiki; Bandow, Shunji; Iijima, Sumio; Shinohara, Hisanori


    Exohedral C60-based metallofullerenes, CsC60, have been synthesized and successfully encapsulated into single-wall carbon nanotubes (SWNTs) in high yield by reducing C60 molecules into anions. High-resolution transmission electron microscopy (HRTEM) images and in situ electron energy loss spectroscopy (EELS) indicate that Cs atoms and C60 molecules align within SWNTs as CsC60 exohedral metallofullerenes, and that the formal charge state of encaged CsC60 is expressed as Cs+1C60-1. The present peapods with the exohedral metallofullerenes provide a new insight and the possibility to fine-tune the electronic and transport properties of carbon nanotubes.

  13. Photosensitization of Nanocrystalline TiO2 Electrode Modifiedwith C60 Carboxylic Acid Derivatives

    Institute of Scientific and Technical Information of China (English)

    张文; 史亚茹; 甘良兵; 黄春辉; 王艳琴; 虎民


    C60 carboxylic acid derivatives can be readily adsorbed on the surface of nanocrystalline TiO2 films act as charge-transfer sensitizer. The electron transport from TiO2 to the C60 derivatives results in the generation of the cathodic photocurrent. The short-circuit photocurrent of a C60 tetracarboxylic acid is 0.45 μA/cm2 under 464 um light illumination. The photoelectric behaviour of ITO electrodes modified by the same C60 carboxylic acids is different from that of the modified TiO2 electrodes, and shows anodic photocurrent.

  14. Classical and quantum studies of the photodissociation of a HX (X=Cl,F) molecule adsorbed on ice. (United States)

    Woittequand, S; Duflot, D; Monnerville, M; Pouilly, B; Toubin, C; Briquez, S; Meyer, H-D


    The photodissociation dynamics of a HX (X = Cl,F) molecule adsorbed on a hexagonal ice surface at T = 0 K is studied using time-dependent quantum wave packets and quasiclassical trajectories. The relevant potential energy surfaces are calculated using high-level ab initio methods. We present here two dimensional calculations for the dynamics of the hydrogen photofragment for both HCl and HF molecules. The purpose of this paper is to compare the photodissociation dynamics of the two molecules which are adsorbed on the ice surface with different equilibrium geometries. The total photodissociation cross section and the angular distribution are calculated. The comparison with classical trajectory calculations provides evidence for typical quantum effects and reveals rainbow structures.

  15. Solubility of C60 in solvent mixtures. (United States)

    Kulkarni, Pradnya P; Jafvert, Chad T


    The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene-acetonitrile, toluene-ethanol, toluene-tetrahydrofuran, and acetonitrile-tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl's equation. The estimated crystal energy term for C60 in tetrahydrofuran was different than that in the other solvents, indicating that the C60 solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal.

  16. 15 CFR 8c.60 - Communications. (United States)


    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Communications. 8c.60 Section 8c.60 Commerce and Foreign Trade Office of the Secretary of Commerce ENFORCEMENT OF NONDISCRIMINATION ON THE... Communications. (a) The agency shall take appropriate steps to ensure effective communication with...

  17. Direct comparison of the electronic coupling efficiency of sulfur and selenium alligator clips for molecules adsorbed onto gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Patrone, L.; Palacin, S.; Bourgoin, J.P


    Scanning tunneling microscopy experiments have been performed to compare the electronic coupling provided by S and by Se used as alligator clips for bisthiol- and biselenol-terthiophene molecules adsorbed onto gold. The molecules were inserted in a dodecanethiol (DT) self-assembled monolayer. Their apparent height above the dodecanethiol matrix was used as a measure of the electronic coupling strength corresponding to S and Se, respectively. We show that the insertion behaviors of the two molecules are qualitatively the same, and that Se provides systematically a better coupling link than S, whatever the tunneling conditions.

  18. The Structure and Mechanical Properties of C60 Fullerite

    Directory of Open Access Journals (Sweden)

    S.O. Rudchenko


    Full Text Available The fullerite films with texture (110 were prepared by the condensation of C60 molecules on KCl, LiF, and Si substrates. The hardness (Н  0,42 GPa and Young’s modulus (Е  14,1 GPa of the fullerite films were determined by nanoindentation method at continuous scanning in depth. The results were compared with theoretical estimates of elastic modules and previous works on measurements of elastic characteristics and hardness of crystalline C60.

  19. Collision dynamics of He@C60+He@C60 at low energies

    Institute of Scientific and Technical Information of China (English)


    A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the dimer structure.

  20. Binary molecular layers of C-60 and copper phthalocyanine on Au(111) : Self-organized nanostructuring

    NARCIS (Netherlands)

    Stöhr, Meike; Wagner, Thorsten; Gabriel, Markus; Weyers, Bastian; Möller, Rolf


    The binary molecular system of C-60 and copper phthalocyanine(CuPc) molecules has been investigated by scanning tunneling microscopy (STM) at room temperature and at 50 K. As substrate Au(111) was chosen. When C-60 and CuPc molecules are sequentially deposited, it is found that well-ordered domains

  1. Some Features of Raman Scattering by Molecules Adsorbed on Metal Crystal Faces and a Fine Light Structure


    Polubotko, A. M.


    The paper analyzes some experiments on Raman scattering by molecules adsorbed on the face (111) of silver monocrystals performed by A. Campion et al. From the existence of the forbidden line of benzene, the conclusion about existence of the surface field, caused by atomic structure of the surface is made. The relatively large intensity of this line allows to make a conclusion about large influence of the electromagnetic field spatial inhomogeneity in crystals on their optical properties. The ...

  2. Photocycloaddition of anthracene to excited C-60

    Energy Technology Data Exchange (ETDEWEB)

    Gol`dshleger, N.F.; Denisov, N.N.; Lobach, A.S. [and others


    The ability to participate in photochemical cycloaddition reactions is characteristic feature of chromophores with a carbon double bond. In this work, the authors demonstrate the formation of an adduct by cycloaddition of anthracene to the triplet-excited C-60 fullerene under anaerobic conditions, which provides a straight forward way to synthesize new derivatives of C-60 fullerenes. Reaction methods, conditions, and mechanisms are included along with the characterization of the fullerene derivative with IR, MS, and NMR methods.

  3. Detection of adsorbed explosive molecules using thermal response of suspended microfabricated bridges

    DEFF Research Database (Denmark)

    Yi, Dechang; Greve, Anders; Hales, Jan Harry;


    Here we present a thermophysical technique that is capable of differentiating vapor phase adsorbed explosives from nonexplosives and is additionally capable of differentiating individual species of common explosive vapors. This technique utilizes pairs of suspended microfabricated silicon bridges...

  4. Shock-wave processing of C60 in hydrogen (United States)

    Biennier, L.; Jayaram, V.; Suas-David, N.; Georges, R.; Singh, M. Kiran; Arunan, E.; Kassi, S.; Dartois, E.; Reddy, K. P. J.


    Context. Interstellar carbonaceous particles and molecules are subject to intense shocks in astrophysical environments. Shocks induce a rapid raise in temperature and density which strongly affects the chemical and physical properties of both the gas and solid phases of the interstellar matter. Aims: The shock-induced thermal processing of C60 particles in hydrogen has been investigated in the laboratory under controlled conditions up to 3900 K with the help of a material shock-tube. Methods: The solid residues generated by the exposure of a C60/H2 mixture to a millisecond shock wave were collected and analyzed using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman micro-spectroscopy, and infrared micro-spectroscopy. The gaseous products were analyzed by Gas Chromatography and Cavity Ring Down Spectroscopy. Results: Volatile end-products appear above reflected shock gas temperatures of 2540 K and reveal the substantial presence of small molecules with one or two C atoms. These observations confirm the role played by the C2 radical as a major product of C60 fragmentation and less expectedly highlight the existence of a single C atom loss channel. Molecules with more than two carbon atoms are not observed in the post-shock gas. The analysis of the solid component shows that C60 particles are rapidly converted into amorphous carbon with a number of aliphatic bridges. Conclusions: The absence of aromatic CH stretches on the IR spectra indicates that H atoms do not link directly to aromatic cycles. The fast thermal processing of C60 in H2 over the 800-3400 K temperature range leads to amorphous carbon. The analysis hints at a collapse of the cage with the formation of a few aliphatic connections. A low amount of hydrogen is incorporated into the carbon material. This work extends the range of applications of shock tubes to studies of astrophysical interest.

  5. First-principles investigation of organic photovoltaic materials C60, C70, [C60]PCBM , and bis-[C60]PCBM using a many-body G0W0 -Lanczos approach (United States)

    Qian, Xiaofeng; Umari, Paolo; Marzari, Nicola


    We present a first-principles investigation of the excited-state properties of electron acceptors in organic photovoltaics including C60, C70, [6,6]-phenyl-C61-butyric-acid-methyl-ester ([C60]PCBM ), and bis-[C60]PCBM using many-body perturbation theory within the Hedin's G0W0 approximation and an efficient Lanczos approach. Calculated vertical ionization potentials (VIP) and vertical electron affinities (VEA) of C60 and C70 agree very well with experimental values measured in the gas phase. The density of states of all three molecules is also compared to photoemission and inverse photoemission spectra measured on thin films, and they exhibit a close agreement—a rigid energy-gap renormalization owing to intermolecular interactions in the thin films. In addition, it is shown that the low-lying unoccupied states of [C60]PCBM are all derived from the highest-occupied molecular orbitals and the lowest-unoccupied molecular orbitals of fullerene C60. The functional side group in [C60]PCBM introduces a slight electron transfer to the fullerene cage, resulting in small decreases of both VIP and VEA. This small change of VEA provides a solid justification for the increase of open-circuit voltage when replacing fullerene C60 with [C60]PCBM as the electron acceptor in bulk heterojunction polymer solar cells.

  6. Resonant core spectroscopies of the charge transfer interactions between C60 and the surfaces of Au(111), Ag(111), Cu(111) and Pt(111) (United States)

    Gibson, Andrew J.; Temperton, Robert H.; Handrup, Karsten; O'Shea, James N.


    Charge transfer interactions between C60 and the metal surfaces of Ag(111), Cu(111), Au(111) and Pt(111) have been studied using synchrotron-based photoemission, resonant photoemission and X-ray absorption spectroscopies. By placing the X-ray absorption and valence band spectra on a common binding energy scale, the energetic overlap of the unoccupied molecular orbitals with the density of states of the underlying metal surface have been assessed in the context of possible charge transfer pathways. Resonant photoemission and resonant Auger data, measuring the valence region as a function of photon energy for C60 adsorbed on Au(111) reveals three constant high kinetic energy features associated with Auger-like core-hole decay involving an electron transferred from the surface to the LUMO of the molecule and electrons from the three highest occupied molecular orbitals, respectively and in the presence of ultra-fast charge transfer of the originally photoexcited molecule to the surface. Data for the C60/Ag(111) surface reveals an additional Auger-like feature arising from a core-hole decay process involving more than one electron transferred from the surface into the LUMO. An analysis of the relative abundance of these core-hole decay channels estimates that on average 2.4 ± 0.3 electrons are transferred from the Ag(111) surface into the LUMO. A core-hole clock analysis has also been applied to assess the charge transfer coupling in the other direction, from the molecule to the Au(111) and Ag(111) surfaces. Resonant photoemission and resonant Auger data for C60 molecules adsorbed on the Pt(111) and Cu(111) surfaces are shown to exhibit no super-Auger features, which is attributed to the strong modification of the unoccupied molecular orbitals arising from stronger chemical coupling of the molecule to the surface.

  7. Charge transfer interactions of a Ru(II) dye complex and related ligand molecules adsorbed on Au(111)

    Energy Technology Data Exchange (ETDEWEB)

    Britton, Andrew J.; Weston, Matthew; O' Shea, James N. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Nottingham Nanotechnology and Nanoscience Centre (NNNC), University of Nottingham, Nottingham NG7 2RD (United Kingdom); Taylor, J. Ben; Rienzo, Anna; Mayor, Louise C. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)


    The interaction of the dye molecule, N3 (cis-bis(isothiocyanato)bis(2,2{sup '}-bipyridyl-4,4{sup '}-dicarboxylato) -ruthenium(II)), and related ligand molecules with a Au(111) surface has been studied using synchrotron radiation-based electron spectroscopy. Resonant photoemission spectroscopy (RPES) and autoionization of the adsorbed molecules have been used to probe the coupling between the molecules and the substrate. Evidence of charge transfer from the states near the Fermi level of the gold substrate into the lowest unoccupied molecular orbital (LUMO) of the molecules is found in the monolayer RPES spectra of both isonicotinic acid and bi-isonicotinic acid (a ligand of N3), but not for the N3 molecule itself. Calibrated x-ray absorption spectroscopy and valence band spectra of the monolayers reveals that the LUMO crosses the Fermi level of the surface in all cases, showing that charge transfer is energetically possible both from and to the molecule. A core-hole clock analysis of the resonant photoemission reveals a charge transfer time of around 4 fs from the LUMO of the N3 dye molecule to the surface. The lack of charge transfer in the opposite direction is understood in terms of the lack of spatial overlap between the {pi}*-orbitals in the aromatic rings of the bi-isonicotinic acid ligands of N3 and the gold surface.

  8. James C. McGroddy Prize Talk: What Was New About C60 (United States)

    Haddon, Robert


    C60 was named molecule of the year by Science in 1991, and in this talk I will discuss what I consider to be the most novel features of the molecule. In some ways C60 is truly unique and the discovery of the molecule in 1985 and its subsequent synthesis in 1990 blazed a trail of new chemical and physical properties that is unlikely to be surpassed by any other molecule. I will discuss the electronic structure of C60, its magnetism, and the conductivity and superconductivity shown by the alkali metal-doped phases.

  9. Magic C60 islands forming due to moiré interference between islands and substrate (United States)

    Olyanich, D. A.; Mararov, V. V.; Utas, T. V.; Utas, O. A.; Gruznev, D. V.; Zotov, A. V.; Saranin, A. A.


    Recently proposed mechanism for self-organized formation of magic islands [Nat.Comm. 4(2013)1679] has received a new experimental confirmation. According to this mechanism, self-assembly is mediated by the moiré interference between an island and underlying substrate lattice. It was first detected at C60 island growth on In-adsorbed Si(111)√{ 3} ×√{ 3}-Au surface. Changing In adsorbate for Tl results in lowering the corrugations of the surface potential relief due to a greater surface metallization. This allows formation of the C60 arrays with novel moiré pattern. As a result, a new set of magic C60 islands is formed on Tl-adsorbed Au/Si(111) surface differing from that observed on In-adsorbed surface. For example, the 19-C60 magic island which has a non-compact boomerang shape on In-adsorbed Au/Si(111) surfaces adopts a shape of a regular hexagon on Tl-adsorbed surface.

  10. A discrete interaction model/quantum mechanical method for describing response properties of molecules adsorbed on metal nanoparticles. (United States)

    Morton, Seth Michael; Jensen, Lasse


    A new polarizable quantum mechanics/molecular mechanics method for the calculation of response properties of molecules adsorbed on metal nanoparticles is presented. This method, which we denote the discrete interaction model/quantum mechanics (DIM/QM) method, represents the nanoparticle atomistically which enables the modeling of the influence of the local environment of a nanoparticle surface on the optical properties of a molecule. Using DIM/QM, we investigate the excitation energies of rhodamine-6G (R6G) and crystal violet (CV) adsorbed on silver and gold nanoparticles of different quasispherical shapes and sizes. The metal nanoparticle is characterized by its static total polarizability, a reasonable approximation for frequencies far from the plasmon resonance. We observe that for both R6G and CV, the presence of the nanoparticle shifts the strongest excitation to the red approximately 40 nm and also increases the oscillator strength of that excitation. The shifts in excitation energies due to the nanoparticle surface are found to be comparable to those due to solvation. We find that these shifts decay quickly as the molecule is moved away from the surface. We also find that the wavelength shift is largest when the transition dipole moment is aligned with the edges of the nanoparticle surface where the electric field is expected to be the largest. These results show that the molecular excitations are sensitive to the local environment on the nanoparticle as well as the specific orientation of the molecule relative to the surface.

  11. Continuous symmetry of C60 fullerene and its derivatives. (United States)

    Sheka, E F; Razbirin, B S; Nelson, D K


    Conventionally, the I(h) symmetry of fullerene C(60) is accepted, which is supported by numerous calculations. However, this conclusion results from the consideration of the molecule electron system, of its odd electrons in particular, in a closed-shell approximation without taking the electron spin into account. Passing to the open-shell approximation has led to both the energy and the symmetry lowering up to C(i). Seemingly contradicting to a high-symmetry pattern of experimental recording, particularly concerning the molecule electronic spectra, the finding is considered in this Article from the continuous symmetry viewpoint. Exploiting continuous symmetry measure and continuous symmetry level approaches, it was shown that formal C(i) symmetry of the molecule is by 99.99% I(h). A similar continuous symmetry analysis of the fullerene monoderivatives gives a reasonable explanation of a large variety of their optical spectra patterns within the framework of the same C(1) formal symmetry exhibiting a strong stability of the C(60) skeleton. TOC color pictures present chemical portrait of C(60) in terms of atomic chemical susceptibility (Sheka, E. Fullerenes: Nanochemistry, Nanomagnetism, Nanomedicine, Nanophotonics; CRC Press: Taylor and Francis Group, Boca Raton, 2011).

  12. C60 as a probe for astrophysical environments

    CERN Document Server

    Brieva, Abel; Jaeger, Cornelia; Huisken, Friedrich; Henning, Thomas


    The C60 molecule has been recently detected in a wide range of astrophysical environments through its four active intramolecular vibrational modes (T1u) near 18.9 {\\mu}m, 17.4 {\\mu}m, 8.5 {\\mu}m, and 7.0 {\\mu}m. The strengths of the mid-infrared emission bands have been used to infer astrophysical conditions in the fullerene-rich regions. Widely varying values of the relative intrinsic strengths (RIS) of these four bands are reported in laboratory and theoretical papers, which impedes the derivation of the excitation mechanism of C60 in the astrophysical sources. The spectroscopic analysis of the C60 samples produced with our method delivers highly reproducible RIS values of 100, 25 +- 1, 26 +- 1 and 40 +- 4. A comparison of the inferred C60 emission band strengths with the astrophysical data shows that the observed strengths cannot be explained in terms of fluorescent or thermal emission alone. The large range in the observed 17.4 {\\mu}m/18.9 {\\mu}m emission ratios indicates that either the emission bands co...

  13. Sublimation of hydrofullerenes C 60H 36 and C 60H 18 (United States)

    Dorozhko, P. A.; Lobach, A. S.; Popov, A. A.; Senyavin, V. M.; Korobov, M. V.


    Thermal behavior of two hydrofullerenes, C 60H 36 and C 60H 18, was studied by means of Knudsen cell mass-spectrometry and infrared spectroscopy. Vapor pressures and enthalpies of sublimation at T=550-685 K were measured. Sublimation of the hydrofullerenes was accompanied by partial loss of hydrogen. Decomposition of C 60H 36 was confirmed to be a stepwise process with formation of C 60H 18 as an intermediate product. The material of the Knudsen cell strongly affected the partial pressures and mass-spectra of the hydrofullerene vapor species.


    NARCIS (Netherlands)

    de Boer, Jan; van Smaalen, Sander; Petricek, Vaclav; Dusek, Michal P.; Verheijen, Marcel A.; Meijer, G.


    C60 crystals were grown from purified powder material with a multiple sublimation technique. In addition to crystals wit a cubic close-packed (ccp) arrangement, crystals were found with a hexagonal close-packed (hcp) structure. Detailed crystallographic evidence is given, including complete refineme

  15. Nonlinear optical response of C60 in solvents: picosecond transient grating experiments (United States)

    Khudyakov, Dmitriy V.; Rubtsov, Igor V.; Lobach, Anatolii S.; Nadtochenko, Victor A.


    Time-resolved resonant nonlinear optical response of C60 in a chlorobenzene solution was measured for 528 nm excitation and 1055, 528, and 351 nm probing for zzzz and zzyy configurations. The slow part of the signal (8 +/- 2 ps) was attributed to the orientational motion of C60 excited molecules.

  16. Structure and dynamics in self-organized C60 fullerenes. (United States)

    Patnaik, Archita


    This manuscript on 'structure and dynamics in self-organized C60 fullerenes' has three sections dealing with: (A) pristine C60 aggregate structure and geometry in solvents of varying dielectric constant. Here, using positronium (Ps) as a fundamental probe which maps changes in the local electron density of the microenvironment, the onset concentration for stable C60 aggregate formation and its phase behavior is deduced from the specific interactions of the Ps atom with the surrounding. (B) A novel methanofullerene dyad, based on a hydrophobic (acceptor C60 moiety)-hydrophilic (bridge with benzene and ester functionalities)-hydrophobic (donor didodecyloxybenzene) network is chosen for investigation of characteristic self-assembly it undergoes leading to supramolecular aggregates. The pi-electronic amphiphile, necessitating a critical dielectric constant epsilon > or = 30 in binary THF-water mixtures, dictated the formation of bilayer vesicles as precursors for spherical fractal aggregates upon complete dyad extraction into a more polar water phase. (C) While the molecular orientation is dependent on the packing density, the ordering of the molecular arrangement, indispensable for self-assembly depends on the balance between the structures demanded by inter-molecular and molecule-substrate interactions. The molecular orientation in a monolayer affects the orientation in a multilayer, formed on the monolayer, suggesting the possibility of the latter to act as a template for controlling the structure of the three dimensionally grown self-assembled molecular aggregation. A systematic study on the electronic structure and orientation associated with C60 functionalized aminothiol self-assembled monolayers on Au(111) surface is presented using surface sensitive Ultra-Violet Photoelectron Spectroscopy (UPS) and C-K edge Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. The results revealed drastic modifications to d-band structure of Au(111) and the

  17. Ortho-para conversion of endohedral water in the fullerene C60 at cryogenic temperatures (United States)

    Shugai, Anna; Nagel, U.; Rõõm, T.; Mamone, S.; Concistrè, M.; Meier, B.; Krachmalnicoff, A.; Whitby, R. J.; Levitt, M. H.; Lei, Xuegong; Li, Yongjun; Turro, N. J.


    Water displays the phenomenon of spin isomerism in which the two proton spins either couple to form a triplet (ortho water, I = 1) or a singlet nuclear spin state (para water, I = 0). Here we study the interconversion of para and ortho water. The exact mechanism of this process is still not fully understood. In order to minimize interactions between molecules we use a sample where a single H2O is trapped in the C60 molecular cage (H2O@C60)andH2O@C60iscrystallized.H2O@C60 has long-lived ortho state and ortho-para conversion kinetics is non-exponential at LHeT. We studied mixtures of H2O@C60, D2O@C60 and C60 using IR absorption, NMR and dielectric measurements. We saw the speeding up of the interconversion with the growth of H2O@C60 concentration in C60 or when D2O@C60 was added. At some temperatures the kinetics is exponential. Models are discussed in order to explain the T and concentration dependence of ortho-para interconversion kinetics. This work was supported by institutional research funding IUT23-3 of the Estonian Ministry of Education and Research.

  18. Control of the dipole layer of polar organic molecules adsorbed on metal surfaces via different charge-transfer channels (United States)

    Lin, Meng-Kai; Nakayama, Yasuo; Zhuang, Ying-Jie; Su, Kai-Jun; Wang, Chin-Yung; Pi, Tun-Wen; Metz, Sebastian; Papadopoulos, Theodoros A.; Chiang, T.-C.; Ishii, Hisao; Tang, S.-J.


    Organic molecules with a permanent electric dipole moment have been widely used as a template for further growth of molecular layers in device structures. Key properties of the resulting organic films such as energy level alignment (ELA), work function, and injection/collection barrier are linked to the magnitude and direction of the dipole moment at the interface. Using angle-resolved photoemission spectroscopy (ARPES), we have systematically investigated the coverage-dependent work function and spectral line shapes of occupied molecular energy states (MESs) of chloroaluminium-phthalocyanine (ClAlPc) grown on Ag(111). We demonstrate that the dipole orientation of the first ClAlPc layer can be controlled by adjusting the deposition rate and postannealing conditions, and we find that the ELA at the interface differs by ˜0.4 eV between the Cl up and down configurations of the adsorbed ClAlPc molecules. These observations are rationalized by density functional theory (DFT) calculations based on a realistic model of the ClAlPc/Ag(111) interface, which reveal that the different orientations of the ClAlPc dipole layer lead to different charge-transfer channels between the adsorbed ClAlPc and Ag(111) substrate. Our findings provide a useful framework toward method development for ELA tuning.

  19. Electronic Structure of Crystalline Buckyballs: fcc-C60 (United States)

    Jalali-Asadabadi, Saeid; Ghasemikhah, E.; Ouahrani, T.; Nourozi, B.; Bayat-Bayatani, M.; Javanbakht, S.; Aliabad, H. A. Rahnamaye; Ahmad, Iftikhar; Nematollahi, J.; Yazdani-Kachoei, M.


    The electronic properties of pristine fcc-C60 are calculated by utilizing a variety of density functional theory (DFT) approaches including the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA), PBE-GGA+DFT-D3(vdW), Engel and Vosko GGA (EV-GGA), GGA plus Hubbard U parameter (GGA+U), hybrids Becke-Perdew-Wang hybrid functional (B3PW91), Becke-Lee-Yang-Parr hybrid functional (B3LYP), the PBE exchange-correlation functional (PBE0), and Tran and Blaha regular and non-regular modified Becke and Johnson (TB-mBJ) potential within a DFT frame work using augmented plane waves plus local orbital method. The comparison of the calculated results with the experimental values shows that the non-regular TB-mBJ method reproduces a correct experimental direct band gap of 2.12 eV at X symmetry for this compound. The effectiveness of this theoretical approach in the reproduction of the experimental band gap is due to the proper treatment of the electrons in the interstitial region of the crystal. Our results show that the C60 clusters are weakly interacting with each other in the fcc crystal. This study also reveals that the five-fold degeneracies of the isolated C60 molecule due to its icosahedral symmetry are completely lifted at an X symmetry point by the crystal field.

  20. Slow Diffusive Motions in a Monolayer of Tetracosane Molecules Adsorbed on Graphite

    DEFF Research Database (Denmark)

    Taub, H.; Hansen, Flemming Yssing; Criswell, L.;


    Monolayers of intermediate-length alkane molecules such as tetracosane (n-C24H50 or C24) serve as prototypes for studying the interfacial dynamics of more complex polymers, including bilayer lipid membranes. Using high-resolution quasielastic neutron scattering (QNS) and exfoliated graphite...... to a temperature of similar to230 K, we observe the QNS energy width to be dispersionless, consistent with molecular dynamics simulations showing rotational motion of the molecules about their long axis. At 260 K, the QNS energy width begins to increase with wave vector transfer, suggesting onset of nonuniaxial...... rotational motion and bounded translational motion. We continue to observe QNS up to the monolayer melting temperature at similar to340 K where our simulations indicate that the only motion slow enough to be visible within our energy window results from the creation of gauche defects in the molecules....

  1. Evidence of Conformational Changes in Adsorbed Lysozyme Molecule on Silver Colloids

    CERN Document Server

    Chandra, Goutam; Dasgupta, Swagata; Roy, Anushree


    In this article, we discuss metal-protein interactions in the Ag-lysozyme complex by spectroscopic measurements. The analysis of the variation in relative intensities of SERS bands reveal the orientation and the change in conformation of the protein molecules on the Ag surface with time. The interaction kinetics of metal-protein complexes has been analyzed over a period of three hours via both Raman and absorption measurements. Our analysis indicates that the Ag nanoparticles most likely interact with Trp-123 which is in close proximity to Phe-34 of the lysozyme molecule.


    Institute of Scientific and Technical Information of China (English)

    曹阳; 陈良进; 陈波; 冯建文; 陈文建


    The three dimensional EHMO crystal orbital calculations for crystalline Ba6 C60,Ca3 C60 and Ca5 C60 are reported.The ground state of partially doped Ca3 C60 is found to be insulating with an indrect energy gap of 0.5eV.In contrast,the Ca5 C60 forms a metallic conducting phase with a set of three half-filled bands crossing the Fermi level which is Found to locate close to a peak of the density of state. The character of crystal orbitals near the Fermilevel for both Ca3 C60 and Ca5 C60 is completely carbon-like.In both cases the Ca3 atoms are almost fully ionized and C60 molecules form a stable negative charge state with six to ten additional electrons.The conductivity of Ba6 C60 is resuted from the incomplete charge tranfer.The valance charge of every Ba ion is about 0.33.The total charge tranfer of six Ba atoms is almost the same as that of five Ca atoms.

  3. Dynamics of molecules adsorbed on a die wall during polymer melt extrusion

    NARCIS (Netherlands)

    Tchesnokov, M.A.; Molenaar, J.; Slot, J.J.M.


    A new, quantitative model to describe the dynamics of polymer molecules grafted on a solid wall is presented. This model is based on the bond vector probability distribution function (BVPDF) which contains the necessary information about the spatial conformations of the grafted chains. All macroscop

  4. Some features of raman scattering by molecules adsorbed on metal crystal faces and a fine light structure (United States)

    Polubotko, A. M.


    The paper analyzes some experiments on Raman scattering by molecules adsorbed on the face (111) of silver monocrystals performed by A. Campion et al. From the existence of the forbidden line A 2 u of benzene, the conclusion about existence of the surface field, caused by atomic structure of the surface is made. The relatively large intensity of this line allows to make a conclusion about large influence of the electromagnetic field spatial inhomogeneity in crystals on their optical properties. The difference between this field and a regular plane wave, which usually describes propagation of electromagnetic field in solids is named as a fine light structure. The influence of this structure on optical properties of solids is pointed out.

  5. Some Features of Raman Scattering by Molecules Adsorbed on Metal Crystal Faces and a Fine Light Structure

    CERN Document Server

    Polubotko, A M


    The paper analyzes some experiments on Raman scattering by molecules adsorbed on the face (111) of silver monocrystals performed by A. Campion et al. From the existence of the forbidden line of benzene, the conclusion about existence of the surface field, caused by atomic structure of the surface is made. The relatively large intensity of this line allows to make a conclusion about large influence of the electromagnetic field spatial inhomogeneity in crystals on their optical properties. The difference between this field and a regular plane wave, which usually describes propagation of electromagnetic field in solids is named as a fine light structure. The influence of this structure on optical properties of solids is pointed out.

  6. Superconductivity at 40K in Cesium Doped C60

    NARCIS (Netherlands)

    Palstra, T.T.M.; Zhou, O.; Iwasa, Y.; Sulewski, P.E.; Fleming, R.M.; Zegarski, B.R.


    We report superconductivity in Cs3C60 at 40K using ac susceptibility measurements under hydrostatic conditions up to 15 kbar. Cs3C60 was prepared by reaction of C60 with Cs in liquid ammonia, followed by heating at 150°C. This route circumvents formation of the energetically more stable Cs1C60 and C

  7. Density Functional Theory and Grand Canonical Monte Carlo Simulations of the Hydrogen Storage Properties of Partially Truncated and Open Cage C60 Fullerenes

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Dong; TANG Yong-Jian; CHENG Xin-Lu; ZHANG Hong


    The potential energies of H2 molecules with partially truncated and open cage C6o fullerenes,including Css,C55,C54(Ⅰ),C54(Ⅱ) and C46,are investigated by means of the density functional theory method.The energy barrier for one H2 molecule (with two postures) entering into the nanocage decreases from 435.59 (513.45)kcal/mol to 3.64 (-2.06) kcal/mol with the increase of the truncated pore.The grand canonical Monte Carlo simulations reveal that each nanocage can accommodate only one H2 molecule inside its cavity at both 77K and 298K.All the other H2 molecules are adsorbed round the truncated pores outside the nanocages.Exceptionally,the truncated C46 can store 2.28wt% H2 molecules at 77K.Therefore,the truncating part of the C60 molecule may be a novel idea to explore C60 fullerene as a hydrogen storage material.Hydrogen is one of the clean and renewable energy carriers used to replace traditional fossil fuels,which have caused great negative effects on the environment.However,the main obstacle for the wide use of hydrogen is its dense and safe storage.[1-3] One proposed method is to physisorbe molecular hydrogen on porous materials.[4-6] Some studies found that metal organic frameworks have the potential to satisfy the goal of gravimetric density of 6wt% hydrogen,[6-9]as set by the U.S.Department of Energy in 2010.However,it is unfortunate that the synthesis of these artificially designed frames is a tremendous obstacle.%The potential energies of H2 molecules with partially truncated and open cage C60 fullerenes, including C58, C55, C54(I), C54(I) and C46, are investigated by means of the density functional theory method. The energy barrier for one H2 molecule (with two postures) entering into the nanocage decreases from 435.59 (513.45) kcal/mol to 3.64 (-2.06) kcal/mol with the increase of the truncated pore. The grand canonical Monte Carlo simulations reveal that each nanocage can accommodate only one H2 molecule inside its cavity at both 77 K and 298 K. All

  8. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; Buendia, Inmaculada M.; Bak, Jimmy;


    In this study, aged aqueous suspensions of C(60) (nC(60)) were investigated in the respirometric OECD test for ready biodegradability. Two suspensions of nC(60) were prepared by stirring and aged under indirect exposure to sunlight for 36 months. ATR-FTIR analyses confirmed the presence of C(60....... After additional 20 days, no mineralisation of nC(60) was observed. However, within a few days sodium acetate was completely mineralised, showing that the biomass was not inhibited by the presence of nC(60). Based on results from this simple approach, aged nC(60) can be classified as not ready...

  9. Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren


    has been applied for deposition of fullerenes for the first time and we have studied the growth of thin films of solid C60. The fragmentation of C60 fullerene molecules induced by ns ablation in vacuum of a frozen anisole target with C60 was investigated by matrix-assisted laser desorption......Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPLE....../ionization (MALDI). Our findings show that intact fullerene films can be produced with laser fluences ranging from 0.15 J/cm2 up to 1.5 J/cm2....

  10. Structure of haloform intercalated C60 and its influence on superconductive properties. (United States)

    Dinnebier, Robert E; Gunnarsson, Olle; Brumm, Holger; Koch, Erik; Stephens, Peter W; Huq, Ashfia; Jansen, Martin


    CHCl3 and CHBr3 intercalated C60 have attracted particular interest after a superconductivity transition temperature (Tc) of up to 117 K was discovered. We have determined the structure using synchrotron x-ray powder-diffraction and found that the expansion of the lattice mainly takes place in one dimension (triclinic b axis), leaving planes of C60 molecules on an approximately hexagonal, slightly expanded lattice. We have performed tight-binding band structure calculations for the surface layer. In spite of the slight expansion of the layers, for the range of dopings where a large Tc has been observed, the density of states at the Fermi energy is smaller for C60.2CHCl3 and C60.2CHBr3 than for C60. This suggests that the lattice expansion alone cannot explain the increase of Tc.

  11. Strong spin-filtering and spin-valve effects in a molecular V-C-60-V contact

    DEFF Research Database (Denmark)

    Koleini, Mohammad; Brandbyge, Mads


    Motivated by the recent achievements in the manipulation of C-60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C-60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111) surface using first-principles calculation...

  12. Switching orientation of adsorbed molecules: Reverse domino on a metal surface (United States)

    Braatz, C. R.; Esat, T.; Wagner, C.; Temirov, R.; Tautz, F. S.; Jakob, P.


    A thus far unknown phase of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA) on Ag(111), characterized by an all perpendicular orientation of the planar molecules and bound to the Ag substrate through the carboxyl oxygen atoms has been identified using infrared absorption spectroscopy and scanning tunneling microscopy. Its formation process requires second layer NTCDA to squeeze into empty spaces between relaxed monolayer NTCDA molecules. Remarkably, this process causes initially parallel oriented NTCDA to likewise adopt the new, highly inclined adsorption geometry. According to our SPA-LEED and STM findings, the new phase displays a distinct long range order and shows a pronounced tendency to form 1D rows or narrow islands. We suggest that extra NTCDA preferentially transforms into the upright configuration close to existing islands and attaches to them, i.e. the transformation process proceeds in a directed and recurrent manner (reverse domino scenario). Identical processing starting with a compressed NTCDA/Ag(111) monolayer leads to a purely parallel oriented bilayer, that is, the NTCDA monolayer phase is retained and merely acts as a passive template for bilayer NTCDA. The new vertical NTCDA phase represents an unusual molecular system with π-orbitals oriented parallel to a metal surface. A substantially reduced coupling of these orbitals to Ag(111) electronic levels is conjectured, which will have a major impact on intermolecular couplings and electronically excited state lifetimes.

  13. Tribochemical synthesis of nano-lubricant films from adsorbed molecules at sliding solid interface: Tribo-polymers from α-pinene, pinane, and n-decane (United States)

    He, Xin; Barthel, Anthony J.; Kim, Seong H.


    The mechanochemical reactions of adsorbed molecules at sliding interfaces were studied for α-pinene (C10H16), pinane (C10H18), and n-decane (C10H22) on a stainless steel substrate surface. During vapor phase lubrication, molecules adsorbed at the sliding interface could be activated by mechanical shear. Under the equilibrium adsorption condition of these molecules, the friction coefficient of sliding steel surfaces was about 0.2 and a polymeric film was tribochemically produced. The synthesis yield of α-pinene tribo-polymers was about twice as much as pinane tribo-polymers. In contrast to these strained bicyclic hydrocarbons, n-decane showed much weaker activity for tribo-polymerization at the same mechanical shear condition. These results suggested that the mechanical shear at tribological interfaces could induce the opening of the strained ring structure of α-pinene and pinane, which leads to polymerization of adsorbed molecules at the sliding track. On a stainless steel surface, such polymerization reactions of adsorbed molecules do not occur under typical surface reaction conditions. The mechanical properties and boundary lubrication efficiency of the produced tribo-polymer films are discussed.

  14. Synthesis of Novel Discotic C60-triphenylene Derivative by 1, 3-Dipolar Cycloaddition

    Institute of Scientific and Technical Information of China (English)

    YANG Fa-fu; GUO Hong-yu; XIE Jian-wei; LIU Zhi-qiang; XU Bing-ting


    1 IntroductionFullerene has received considerable attention and a great researching interest due to its unique structure and interesting properties[1-3].Many functional groups have been introduced,often region-or stereo-selectively,for tuning the physical properties of C60 and for constructing supramolecular architectures[4-6].Among all kinds of C60 derivatives,the diseotic molecule-substituted C60 derivatives show interesting properties,especially,liquid crystal properties.Up to now,few C60 derivatives with discotic-molecular groups and their liquid crystal properties have been studied.In 1996,Deschenaux et al.[7]reported the first mesomorphic C60-ferrocene derivative.Tian et al.[8]synthesized a C60-perylene derivative in 2004.Nakanishi et al.[9]prepared a series of uncommon liquid C60derivatives with 2,4,6-tris(alkyloxy)benzal groups in 2006.Lately,Geerts et al.[10]described the synthesis of mesogenic phthalocyanine-C60.

  15. Sorption of nano-C60 clusters in soil: hydrophilic or hydrophobic interactions? (United States)

    Forouzangohar, Mohsen; Kookana, Rai S


    We studied the sorption behaviour of fullerene nano-C(60) particles (nC(60)) in soil from binary solvent mixtures of ethanol-water in order to critically evaluate the previous reports in the literature that the partitioning mechanism explains the soil sorption of fullerene C(60) as hydrophobic molecules. The sorption of nC(60) particles was studied in a range of solvent mixtures by changing volume fractions of ethanol from 20 to 100 percent. Sorption and particle characteristics were found to be very different in ethanol : water mixtures above and below 60% ethanol. In the range of 20-60% ethanol, sorption increased from 1.2 to 14.6 L kg(-1) accompanied by a change in zeta (ζ) potential from -32.4 to -7.2 mV. This observation can be attributed to hydrophilic interactions that negatively charged nC(60) particles undergo with soil colloids and water molecules. From 60% to 100% ethanol volume fractions, hydrophobic interactions of weakly charged nanoparticles may control the overall extent of soil sorption. The findings of this study indicate the importance of hydrophilic forces in controlling the sorption behaviour of nC(60) particles which are stabilized in water dominated solvent mixtures. The validity of the partitioning mechanism and K(OC) modelling approach in describing and estimating the sorption of nC(60) particles in soil (previously suggested in the literature) are, therefore, questioned.

  16. A Relative Study on Two-photon Absorption Properties of C60 and C70

    Institute of Scientific and Technical Information of China (English)

    ZHOU,Xin(周新); REN,Ai-Min(任爱民); FENG,Ji-Kang(封继康); LIU,Xiao-Juan(刘孝娟)


    We have theoretically investigated the one- and two-photon absorption properties of C60 and C70 using the ZINDO method. From the results it is suggested that the one-photon absorption spectra are in agreement with the experimental observations. It is found that the maximum TPA cross section of C70 is more than twice that of C60,which is consistent with the experimental results. A notable point is that the TPA process of C60 is different from that of C70 as well as other ordinary conjugated molecules.

  17. Transfer of chirality from adsorbed chiral molecules to the substrates highlighted by circular dichroism in angle-resolved valence photoelectron spectroscopy

    DEFF Research Database (Denmark)

    Contini, G.; Turchini, S.; Sanna, Simone


    Studies of self-assembled chiral molecules on achiral metallic surfaces have mostly focused on the determination of the geometry of adsorbates and their electronic structure. The aim of this paper is to provide direct information on the chirality character of the system and on the chirality trans...

  18. Preparation and vibrational modes of C60·2CHBr3

    Institute of Scientific and Technical Information of China (English)


    C60·2CHBr3 polycrystalline powder was prepared by the solution method. The vibrational modes of the sample were studied by Raman scattering and infrared adsorption techniques. The Raman spectra showed that the Ag modes were downshifted by 4-5 cm1, while the Hg(1) mode was unshifted. The analyses of the downshifts of the Ag modes revealed that a small amount of electrons were transferred from the hydrogen atoms to the C60 molecules. In the infrared spectra, the F1u modes of the pristine C60 were unshifted after the intercalation with CHBr3. However, the vibrational modes of CHBr3 changed remarkably. The C-Br stretching mode was downshifted by ~4 cm1. The adsorption of the C-H twisting mode was weakened obviously, and the adsorption of the C-H stretching mode was not observed. These results exhibited that there were nonnegligible interactions between CHBr3 and C60 molecules, and that the strongest interaction took place between the hydrogen atoms and the C60 molecules. The interaction should induce not only the changes of the vibrational modes reported here, but also those of the electronic states. So this work should offer important glues to the mechanism of the superconductivity at 117 K of the field-doped C60·2CHBr3.

  19. The manipulation of C60 in molecular arrays with an STM tip in regimes below the decomposition threshold. (United States)

    Olyanich, Dmitry A; Kotlyar, Vasily G; Utas, Tatiana V; Zotov, Andrey V; Saranin, Alexander A


    The ability of scanning tunneling microscopy to manipulate selected C(60) molecules within close packed C(60) arrays on a (Au,In)/Si(111) surface has been examined for mild conditions below the decomposition threshold. It has been found that knockout of the chosen C(60) molecule (i.e., vacancy formation) and shifting of the C(60) molecule to the neighboring vacant site (if available) can be conducted for wide ranges of bias voltages (from -1.5 to +0.5 V), characteristic manipulation currents (from 0.02 to 100 nA) and powers (from 2 × 10(-8) to 0.1 μW). This result implies that the manipulation is not associated with the electrical effects but rather has a purely mechanical origin. The main requirement for successful C(60) knockout has been found to be to ensure a proper 'impact parameter' (deviation from central impact on the C(60) sphere by the tip apex), which should be less than ~1.5 Å. A certain difference has been detected for the manipulation of C(60) in extended molecular arrays and molecular islands of a limited size. While it is possible to manipulate a single C(60) molecule in an array, in the case of a C(60) island it appears difficult to manipulate a given fullerene without affecting the other ones constituting the island.

  20. Strain Lattice Imprinting in Graphene by C60 Intercalation at the Graphene/Cu Interface

    NARCIS (Netherlands)

    Monazami, Ehsan; Bignardi, Luca; Rudolf, Petra; Reinke, Petra


    Intercalation of C60 molecules at the graphene-substrate interface by annealing leads to amorphous and crystalline intercalated structures. A comparison of topography and electronic structure with wrinkles and moiré patterns confirms intercalation. The intercalated molecules imprint a local strain/d

  1. Thermoelectric properties of Bi0.5Sb1.5Te3/C60 nanocomposites

    NARCIS (Netherlands)

    Blank, V.D.; Buga, S.G.; Kulbachinskii, V.A.; Kytin, V.G.; Medvedev, V.V.; Popov, Y.M.; Stepanov, P.B.; Skok, V.F.


    A thermoelectric nanocomposite of Bi0.5Sb1.5Te3 with the C60 fullerene molecules has been synthesized and studied. The fullerene molecules provide the phonons blocking, reducing the lattice thermal conductivity. The reduction of the electrical conductivity is much less than the heat conductivity red

  2. Photon-exposure-dependent photon-stimulated desorption for obtaining photolysis cross section of molecules adsorbed on surface by monochromatic soft x-ray photons. (United States)

    Chou, L-C; Jang, C-Y; Wu, Y-H; Tsai, W-C; Wang, S-K; Chen, J; Chang, S-C; Liu, C-C; Shai, Y; Wen, C-R


    Photon-exposure-dependent positive- and negative-ion photon-stimulated desorption (PSD) was proposed to study the photoreactions and obtain the photolysis cross sections of molecules adsorbed on a single-crystal surface by monochromatic soft x-ray photons with energy near the core level of adsorbate. The changes in the F(+) and F(-) PSD ion yields were measured from CF(3)Cl molecules adsorbed on Si(111)-7x7 at 30 K (CF(3)Cl dose=0.3x10(15) molecules/cm(2), approximately 0.75 monolayer) during irradiation of monochromatic soft x-ray photons near the F(1s) edge. The PSD ion yield data show the following characteristics: (a) The dissociation of adsorbed CF(3)Cl molecules is due to a combination of direct photodissociation via excitation of F(1s) core level and substrate-mediated dissociation [dissociative attachment and dipolar dissociation induced by the photoelectrons emitting from the silicon substrate]. (b) the F(+) ion desorption is associated with the bond breaking of the surface CF(3)Cl, CF(2)Cl, CFCl, and SiF species. (c) the F(-) yield is mainly due to DA and DD of the adsorbed CF(3)Cl molecules. (d) The surface SiF is formed by reaction of the surface Si atom with the neutral fluorine atom, F(+), or F(-) ion produced by scission of C-F bond of CF(3)Cl, CF(2)Cl, or CFCl species. A kinetic model was proposed for the explanation of the photolysis of this submonolayer CF(3)Cl-covered surface. Based on this model and the variation rates of the F(+)F(-) signals during fixed-energy monochromatic photon bombardment at 690.2 and 692.6 eV [near the F(1s) edge], the photolysis cross section was deduced as a function of energy.

  3. Degradability of aged aquatic suspensions of C60 nanoparticles

    DEFF Research Database (Denmark)

    Hartmann, B.; Buendia, Inmaculada M.; Baun, Anders


    While studies of the potential human and environmental effects of C60 and its derivatives are emerging in the scientific literature, the environmental fate of C60 is still largely unknown. In this study, aged aqueous suspensions of C60 (nC60) were investigated in the respirometric OECD test...... for ready biodegradability. Two suspensions of nC60 were prepared by stirring and aged under indirect exposure to sunlight for 36 months, which resulted in relatively stable suspensions with a dark-brown colour. The suspended nC60 could not be extracted into toluene and indicating that the particles were...... mineralized within a few days. Even with this additional carbon source no mineralization of nC60 was observed after an additional 20 days. Based on these results, aged nC60 can be classified as not ready biodegradable according to the OECD test procedure....


    Directory of Open Access Journals (Sweden)

    S. V. Prylutska


    Full Text Available The literature data and own research results concerning antitumor effect in vitro and in vivo of C60 fullerene and its derivatives, cytostatics, and conjugated systems on their basis, which enable the practical application of C60 in combined chemotherapy for treatment efficacy improving of malignant tumors are generalized. The mechanism of antitumor action of C60 fullerene in combined treatment with cytostatics is based on antioxidant properties of its molecule, thereby reducing toxic side effects of traditional drugs in a body and ability to their transport purposefully into the target cells. The unique structure of C60 enables to modify its surface with chemotherapeutic drugs. Under combined action of the "fullerene C60-chemotherapy drug" conjugate the anti-tumor effects enhancement is observed both in vitro and in vivo, namely quantity reduction of viable tumor cells, tumor reduction etc. Furthermore, protective effects of fullerene C60 and derivatives relatively toxic effects of chemotherapeutic agents in a body were observed. Conjugate auxesis empowers it to be kept longer in a cell and prolong the duration of drug action. Ability of fullerene C60 to selective accumulation provides its using for target drug delivery.

  5. Probing Exciton Diffusion and Dissociation in Single-Walled Carbon Nanotube-C60 Heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Dowgiallo, Anne-Marie; Mistry, Kevin S.; Johnson, Justin C.; Reid, Obadiah G.; Blackburn, Jeffrey L.


    The efficiency of thin-film organic photovoltaic (OPV) devices relies heavily upon the transport of excitons to type-II heterojunction interfaces, where there is sufficient driving force for exciton dissociation and ultimately the formation of charge carriers. Semiconducting single-walled carbon nanotubes (SWCNTs) are strong near-infrared absorbers that form type-II heterojunctions with fullerenes such as C60. Although the efficiencies of SWCNT-fullerene OPV devices have climbed over the past few years, questions remain regarding the fundamental factors that currently limit their performance. In this study, we determine the exciton diffusion length in the C60 layer of SWCNT-C60 bilayer active layers using femtosecond transient absorption measurements. We demonstrate that hole transfer from photoexcited C60 molecules to SWCNTs can be tracked by the growth of narrow spectroscopic signatures of holes in the SWCNT 'reporter layer'. In bilayers with thick C60 layers, the SWCNT charge-related signatures display a slow rise over hundreds of picoseconds, reflecting exciton diffusion through the C60 layer to the interface. A model based on exciton diffusion with a Beer-Lambert excitation profile, as well as Monte Carlo simulations, gives the best fit to the data as a function of C60 layer thickness using an exciton diffusion length of approximately 5 nm.

  6. Important role of alkali atoms in A4C60


    Gunnarsson, O.; Erwin, S. C.; Koch, E.; Martin, R. M.


    We show that hopping via the alkali atoms plays an important role for the t1u band of A4C60 (A=K, Rb), in strong contrast to A3C60. Thus the t1u band is broadened by more than 40 % by the presence of the alkali atoms. The difference between A4C60 and A3C60 is in particular due to the less symmetric location of the alkali atoms in A4C60.

  7. The Curators of the University of Missouri Modeling the Infrared Emission of C_60 in Space (United States)

    Li, Aigen

    Fullerenes are cage-like molecules of pure carbon, such as C_60, C_70, C_76, and C_84. C_60, also known as buckminsterfullerene, is the most stable fullerene and has a soccer- ball like structure. The presence of fullerenes in space has been suggested and observationally explored since their first synthesis in the laboratory in 1985 by Harry Kroto and his colleagues which earned them the 1996 Nobel prize in chemistry. C_60 (as well as C_70) has recently been detected in reflection nebulae, post-AGB stars, protoplanetary nebulae, planetary nebulae, Herbig Ae/Be stars, and young stellar objects through their characteristic infrared emission bands. The formation of C_60 in interstellar and circumstellar environments is not firmly established. Experimental studies have shown that C_60 can be made by gas-phase condensation (e.g. through vaporization of graphite) in a hydrogen-poor environment. In view of the simultaneous detection of C_60 and PAHs in hydrogen-rich interstellar and circumstellar regions, it has also been suggested that C_60 could be generated by the decomposition of hydrogenated amorphous carbon, or the destruction of PAHs, both induced by shocks and/or UV photoprocessing. The phase (gas or solid) and excitation mechanism of C_60 in interstellar and circumstellar conditions are also hotly debated in the literature. One model suggests that C_60 is attached to dust and emits in solid-phase at the equilibrium temperature of the dust. Another model suggests that C_60 is stochastically excited by UV photons and emits in the gas-phase. We prefer the latter model as in interstellar and circumstellar conditions the energy content of a C_60 molecule is often smaller than the energy of a single starlight photon and C_60 is expected to undergo stochastical heating. We propose a two-year project to model the vibrational excitation of C_60 and calculate its infrared emission spectra in a wide variety of regions (e.g. reflection nebulae excited by stars of a range of

  8. Rotational reorientation dynamics of C60 in various solvents. Picosecond transient grating experiments (United States)

    Rubtsov, I. V.; Khudiakov, D. V.; Nadtochenko, V. A.; Lobach, A. S.; Moravskii, A. P.


    The picosecond transient grating technique has been used to study the rotational reorientation of C60 in various solvents: in toluene 7 +/- 1.5 ps, o-dichlorobenzene 10.3 +/- 1.5 ps, o-xylene 13 +/- 2 ps and in decalin 3.5 +/- 1.5 ps. The data obtained cannot be described by hydrodynamic Debye theory. Rough-sphere fluid theory predicts the correct values for C60 rotation in toluene, o-dichlorobenzene and in decalin. The deviations for o-xylene are probably connected with the specifics of the local solvent structure or with the stronger interaction of C60 with solvent molecules. The rotation of C60 in decalin is rapid and approaches the rotation in the gas phase determined by inertia.

  9. Orientational Phase Transition Around 274 K in C60 Single Crystal

    Institute of Scientific and Technical Information of China (English)

    徐亚伯; 何丕模; 杨宏顺; 郑萍; 余朝文; 陈兆甲; 张宣嘉; 李文铸


    The electrical conductivity of a C60 single crystal around 274 K and the specific heat of C60 crystals from 150 to 340 K have been measured.The delta-like specific heat peak at about 251 K related to the first-order phase transition has been reported.The activation energy change around 274 K and the lambda-like specific heat peak beginning at 270 K and ending at 310 K show that there is an orientational phase transition in fcc C60 crystals above 251 K.By taking the symmetry into consideration and further analyzing lambda-like specific heat peak and the activation energy change around 274 K,the conclusion has been reached that this new phase transition is an orientational structure transition from the merohedral twinning fcc to the orientationally disordered fcc.The temperature of free rotation of C60 molecules is about 281 K.

  10. Structure and electronic properties of alkali-C60 nanoclusters. (United States)

    Rabilloud, Franck


    I investigated the structural and electronic properties of both Na(n)C(60) and Li(n)C(60) (n alkali atoms over the C(60) surface is analyzed. The hypotheses for either an homogeneous coating of the C(60) surface by the alkali atoms or the growth of an alkali droplet not wetting the fullerene surface are discussed. Lithium atoms are found to coat homogeneously the fullerene on the C(60) surface via pentagonal sites, contrary to sodium atoms, which prefer to form 4-atom islands on the surface. The charge transfer, the energetics, and the dipole moments are discussed in relation with available results. The adsorption of alkali atoms on the C(60) surface considerably enhances the capacity of C(60) to accept electrons. The arrangement of lithium atoms seems more favorable for the hydrogen storage than that of sodium atoms.

  11. Production of Self-Assembled Fullerene (C60) Nanocrystals at Liquid-Liquid Interface. (United States)

    Shrestha, Rekha Goswami; Shrestha, Lok Kumar; Abe, Masahiko; Ariga, Katsuhiko


    Here we present self-assembled nanostructure of functional molecule fullerene (C60) at liquid-liquid interface. The nanostructured nanocrystals were grown at liquid-liquid interface of isopropyl alcohol (IPA) and C60 solution in butylbenzene under ambient condition of temperature and pressure, and characterized by Raman scattering, power X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystal formation mechanism is driven by supersaturation related to the low solubility of C60 in IPA. A slow diffusion of IPA towards the C60 solution causes unsaturation of C60 at the liquid-liquid interface and consequently small clusters of C60 is formed at the interface, which acts as the nucleation site. Further diffusion of IPA supplies the C60 molecules from bulk to the interface promoting the crystal growth. Based on SEM and TEM observation, the average size of the individual hexagonal bipyramid nanocrystal is found to be ca. 1.4 µm and the average size of their assembly is found to be approximately 2 µm. XRD measurements have shown that these materials are crystalline with mixed face-centered cubic (cell dimension: a = 1.352 nm, and V = 2.475 nm3) and hexagonal (cell dimension: a = 1.452 nm, c = 1.207 nm, c/a = 0.831, and V = 2.475 nm3) structures. Raman scattering measurements showed two Ag and six Hg vibration bands, which are similar to those obtained in the pristine C60.

  12. In situ STM imaging of bis-3-sodiumsulfopropyl-disulfide molecules adsorbed on copper film electrodeposited on Pt(111) single crystal electrode. (United States)

    Tu, HsinLing; Yen, PoYu; Chen, Sihzih; Yau, ShuehLin; Dow, Wei-Ping; Lee, Yuh-Lang


    The adsorption of bis-3-sodiumsulfopropyldi-sulfide (SPS) on metal electrodes in chloride-containing media has been intensively studied to unveil its accelerating effect on Cu electrodeposition. Molecular resolution scanning tunneling microscopy (STM) imaging technique was used in this study to explore the adsorption and decomposition of SPS molecules concurring with the electrodeposition of copper on an ordered Pt(111) electrode in 0.1 M HClO(4) + 1 mM Cu(ClO(4))(2) + 1 mM KCl. Depending on the potential of Pt(111), SPS molecules could react, adsorb, and decompose at chloride-capped Cu films. A submonolayer of Cu adatoms classified as the underpotential deposition (UPD) layer at 0.4 V (vs Ag/AgCl) was completely displaced by SPS molecules, possibly occurring via RSSR (SPS) + Cl-Cu-Pt → RS(-)-Pt(+) + RS(-) (MPS) + Cu(2+) + Cl(-), where MPS is 3-mercaptopropanesulfonate. By contrast, at 0.2 V, where a full monolayer of Cu was presumed to be deposited, SPS molecules were adsorbed in local (4 × 4) structures at the lower ends of step ledges. Bulk Cu deposition driven by a small overpotential (η deposit at the very beginning (deposit, the chloride adlayer was still adsorbed to afford SPS admolecules arranged in a unique 1D striped phase. SPS molecules could decompose into MPS upon further Cu deposition, as a (2 × 2)-MPS structure was observed with prolonged in situ STM imaging. It was possible to visualize either SPS admolecules in the upper plane or chloride adlayer sitting underneath upon switching the imaging conditions. Overall, this study established a MPS molecular film adsorbed to the chloride adlayer sitting atop the Cu deposit.

  13. Investigation of tribological properties of composite C60-LB films

    Institute of Scientific and Technical Information of China (English)

    YANG Guanghong; ZHANG Xingtang; XUN Jun; JIANG Xiaohong; ZHANG Pingyu; DU Zuliang


    Composite C60-LB films were fabricated by the Langmuir-Blodgett (LB) technique, their micro- structures, micro- and macro-tribological properties were investigated using atomic force microscope/ friction force microscope (AFM/FFM). The results showed that in the confined C60-LB films there were two kinds of structures for the special C60 assembly: grain diameters of one kind were in the range of 150-230 nm; the other was smaller than 20 nm. Mi-cro-tribological studies showed that topographical images of tiny C60 aggregates (<20 nm) were con-sistent with their frictional ones very well, namely, low friction occurred on tiny C60 aggregates compared with fatty chains LB monolayer, and 'Micro-rolling effect' was apparent; but for big large ones frictional forces were relatively high and 'ratchet mechanism' was seen apparently. Macro-tribological data proved large C60 aggregates had wear resistance and load-carrying capacities and anti-wear lives for com- posite C60-LB films were prolonged greatly with dis-persibility of C60 improved and its grain diameter re-duced. Tiny C60 aggregates were mainly the lubricating agents. Friction coefficients of composite C60-LB films gradually reduced with loads increasing having the same friction coefficient-load relations with boundary lubrication films.

  14. Controlling the Electronic and Structural Coupling of C60 Nano Films on Fe(001) through Oxygen Adsorption at the Interface. (United States)

    Picone, Andrea; Giannotti, Dario; Riva, Michele; Calloni, Alberto; Bussetti, Gianlorenzo; Berti, Giulia; Duò, Lamberto; Ciccacci, Franco; Finazzi, Marco; Brambilla, Alberto


    C60 molecules coupled to metals form hybrid systems exploited in a broad range of emerging fields, such as nanoelectronics, spintronics, and photovoltaic solar cells. The electronic coupling at the C60/metal interface plays a crucial role in determining the charge and spin transport in C60-based devices; therefore, a detailed understanding of the interface electronic structure is a prerequisite to engineering the device functionalities. Here, we compare the electronic and structural properties of C60 monolayers interfaced with Fe(001) and oxygen-passivated Fe(001)-p(1 × 1)O substrates. By combining scanning tunneling microscopy and spectroscopy, Auger electron spectroscopy, photoemission and inverse photoemission spectroscopies, we are able to elucidate the striking effect of oxygen on the interaction between Fe(001) and C60. Upon C60 deposition on the oxygen-passivated surface, the oxygen layer remains buried at the C60/Fe(001)-p(1 × 1)O interface, efficiently decoupling the fullerene film from the metallic substrate. Tunneling and photoemission spectroscopies reveal the presence of well-defined molecular resonances for the C60/Fe(001)-p(1 × 1)O system, with a large HOMO-LUMO gap of about 3.4 eV. On the other hand, for the C60/Fe(001) interface, a strong hybridization between the substrate states and the C60 orbitals occurs, resulting in broader molecular resonances.

  15. Laser desorption of NO from a thick C 60 film (United States)

    Hoger, T.; Marzok, C.; Jongma, R. T.; Zacharias, H.


    The desorption of NO molecules from a thick C 60 film is reported. A thermal desorption spectrum indicates two adsorption sites with binding energies of Eb = 0.30 eV and 0.55 eV. For laser desorption the fullerene surface is exposed to NO and excited by 7 ns UV laser pulses. Desorbing NO molecules are recorded state selectively as well as time resolved. The time-of-flight measurement indicates three different desorption pathways. A fast channel shows rovibronic temperatures of Trot( v″ = 0) = 370 K, Trot( v″ = 1) = 390 K and Tvib = 610 K as well as strong rotational-translational coupling. The desorption yield for the fast channel increases linearly with pulse energy with a desorption cross section of σ = (5.1 ± 0.9) × 10 -17 cm 2. Dominating the signal for small J″ values is a slow channel with low rotational and translational temperatures of about 110 K. We assign this peak to a laser-induced thermal desorption. For large pump-probe delays the data deviate from the Maxwellian flux distribution and a third channel appears with extremely late arrival times.

  16. Change of 7Be decay rate in exohedral and endohedral C60 fullerene compounds and its implications

    CERN Document Server

    Ray, A; Saha, S K; Das, S K; Das, J J; Madhavan, N; Nath, S; Sugathan, P; Rao, P V M; Jhingan, A


    The half-life of 7Be implanted in a C60 pellet and gold foil has been measured to be about the same within about 0.2%. Using a radiochemical technique, we also measured that the probability of formation of endohedral 7Be@C60 by nuclear implantation technique was (5.6+-0.45)%. It is known from earlier works that the half-life of endohedral 7Be@C60 is about 1.2% shorter than that of 7Be implanted in gold. An analysis of these results using linear muffin-tin orbital method calculations indicates that most of the implanted 7Be ions in fullerene C60 stay at a distance of about 5.3 Angstrom from the centers of nearest C60 molecules forming exohedral compounds and those who enter the fullerene cages go to the centers of the cages forming endohedral 7Be@C60 compounds.

  17. Coulomb expansion of a van der Waals C60 solid film

    Institute of Scientific and Technical Information of China (English)

    薛其坤; 厉建龙; 孙牧; 陆华; T.Hashizume; Y.Hasegawa; K.Ohno; Y.Kawazoe; T.Sakurai; H.Kamiyama; H.Shinohara


    Scanning tunneling microscopy study revealed a van der Waals C60, solid film with 13% room-temperature lattice expansion on the GaAs(001) 2×4 surface. The mechanism involves fundamental Coulomb interaction due to charge transfer from the GaAs substrate. Theoretical calculation determines the charge transfer to be 1.76 electrons per C60 molecule. Oriented at its (110) crystallo-graphic axis this film also distinguishes itself from those formed on all other semiconductor and metal substrates where only the low-energy (111) hexagonal packing of C60 molecules was developed. It is shown that this is due to the one-dimensional confinement effect of the anisotropic substrate, which may have the prospect of controlling crystal growth.

  18. Growth of centimeter-sized C60 single crystals

    Institute of Scientific and Technical Information of China (English)

    李宏年; 徐亚伯; 张建华; 何丕模; 李海洋; 吴太权; 鲍世宁


    C60 single crystals larger than one centimeter in size are grown with vapor method by nucleation control and by a proper time-dependent temperature process which allows only one nucleus growing larger and larger. X-ray diffraction patterns exhibit the high quality of the sample. As an example of the applications of large single C60 crystals,svnchrotron radiation photoemission spectra are measured to investigate the fine structure of valence bands of C60 crystals.

  19. Diamond nucleation on surface of C60 thin layers

    Institute of Scientific and Technical Information of China (English)

    杨国伟; 袁放成; 刘大军; 何金田; 张兵临


    Diamond nucleation on the surface of C60 thin layers and intermediate layer of Si substrates are studied by scanning electron microscopy (SEM). The cross-section SEM images of diamond films show that diamond grains really nucleate on the surface of C60 thin layers. The SEM images of diamond nucleating sites show the nucleating aggregation of diamond on C60 surfaces. The preferential oriented diamond films are observed. The plasma pre-treatment of C60 sublimating layers is a key factor for diamond nucleation.

  20. Fullerene-C60 and crown ether doped on C60 sensors for high sensitive detection of alkali and alkaline earth cations (United States)

    Zaghmarzi, Fatemeh Alipour; Zahedi, Mansour; Mola, Adeleh; Abedini, Saboora; Arshadi, Sattar; Ahmadzadeh, Saeed; Etminan, Nazanin; Younesi, Omran; Rahmanifar, Elham; Yoosefian, Mehdi


    Fullerenes are effective acceptor components with high electron affinity for charge transfer. The significant influences of chemical adsorption of the cations on the electrical sensitivity of pristine C60 and 15-(C2H4O)5/C60 nanocages could be the basis of new generation of electronic sensor design. The density functional theory calculation for alkali and alkaline earth cations detection by pristine C60 and 15-(C2H4O)5/C60 nanocages are considered at B3LYP level of theory with 6-31 G(d) basis set. The quantum theory of atoms in molecules analysis have been performed to understand the nature of intermolecular interactions between the cations and nanocages. Also, the natural bond orbital analysis have been performed to assess the intermolecular interactions in detail. Furthermore, the frontier molecular orbital, energy gap, work function, electronegativity, number of transferred electron (∆N), dipole moment as well as the related chemical hardness and softness are investigated and calculated in this study. The results show that the adsorption of cations (M=Na+, K+, Mg2+ and Ca2+) are exothermic and the binding energy in pristine C60 nanocage and 15-(C2H4O)5/C60 increases with respect to the cations charge. The results also denote a decrease in the energy gap and an increase in the electrical conductivity upon the adsorption process. In order to validate the obtained results, the density of state calculations are employed and presented in the end as well.

  1. Topochemical 3D polymerization of C60 under high pressure at elevated temperatures. (United States)

    Yamanaka, Shoji; Kini, Nagesh S; Kubo, Akira; Jida, Saeko; Kuramoto, Hideaki


    Fullerene C60 monomer crystals were compressed to a face-centered cubic (fcc) phase with a lattice parameter of a = 11.93(5) A and a micro-Vickers hardness of 4500 kg/mm2 using high-pressure and high-temperature conditions of 15 GPa at 500-600 degrees C. The hardness is compatible with that of cubic boron nitride (c-BN), suggesting the formation of a 3D C60 polymer. The single-crystal X-ray structural analysis revealed that each C60 molecule in the polymer was linked to the 12 nearest neighbors by [2+2] cycloaddition between the common pentagon-hexagon (56) edges. However, ab initio geometry optimization and molecular dynamics calculations suggested that the 3D polymer should have a rhombohedral structure with the space group of R containing [3+3] cycloaddition between the pentagons of C60 molecules within the plane perpendicular to the 3-fold axis. The higher apparent symmetry of fcc was observed as an averaged structure of different orientations of the rhombohedral structure. The R structure can be derived by only a slight rotation of each C60 unit in the (111) plane of the fcc structure. The band-structure calculation suggested that the 3D polymer (R) was a semiconductor; the activation energy for the electrical conductivity was experimentally determined to be 0.25 eV at 550 K.

  2. Synthesis of novel organo-phosphorus C60 dimers

    Institute of Scientific and Technical Information of China (English)


    Carbon bridged organophosphorus C60 dimers were obtained by the reaction of aminome- thylenebisphosphonate anion with C60 and fully characterized by 1HNMR, 31PNMR, 13CNMR, FT- MALDI-MS, FT-IR, UV-Vis, DEPT and HMBC, and the dimeric compounds undergo hydrolysis by using TMSI.

  3. Adsorption of $^4$He on a single C$_{60}$


    Szybisz, Leszek; Urrutia, Ignacio


    The adsorption of $^4$He inside and outside a single fullerene C$_{60}$ is studied. A physisorption potential is proposed. The energetics and structural features of C$_{60}$-$^4$He$_N$ clusters are investigated. Particular attention is paid to the growth of the highly pronounced layered density profile. The evolution towards bulk liquid and surface thickness at the free interface are discussed.

  4. Adsorption of 4He on a Single C60 (United States)

    Szybisz, L.; Urrutia, I.


    The adsorption of $^4$He inside and outside a single fullerene C$_{60}$ is studied. A physisorption potential is proposed. The energetics and structural features of C$_{60}$-$^4$He$_N$ clusters are investigated. Particular attention is paid to the growth of the highly pronounced layered density profile. The evolution towards bulk liquid and surface thickness at the free interface are discussed.

  5. Synthesis and Photophysical Properties of C60-carbazole Adducts

    Institute of Scientific and Technical Information of China (English)

    YIN ,Gui(尹桂); YIN,Gui; MAO,Xin-Ping(毛新平); MAO,Xin-Ping; SUO,Zhi-Yong(锁志勇); SUO,Zhi-Yong; XU,Zheng(徐正); XU,Zheng


    Three C60-cartazole adducts have been synthesized by 1,3-dipolar cycloaddition reaction.Intramolecular energy/electron transfer from carbazole to C60 was observed by steady-state absorption and fluorescence spectra.The fluorescence spectra of these adducts were similau to each other and dependent on the excitation wavelength and solvent.

  6. Silanization of polyelectrolyte-coated particles: an effective route to stabilize Raman tagging molecules adsorbed on micrometer-sized silver particles. (United States)

    Kim, Kwan; Lee, Hyang Bong; Shin, Kuan Soo


    Micrometer-sized Ag (microAg) powders are very efficient surface-enhanced Raman scattering (SERS) substrates. To use microAg powders as a core material for molecular sensors operating via SERS, it is necessary to stabilize the tagging (i.e., SERS-marker) molecules adsorbed onto them. We demonstrate in this work that once the tagging molecules are coated with aliphatic polyelectrolytes such as poly(allylamine hydrochloride), the base-catalyzed silanization can be readily carried out to form stable silica shells around the polyelectrolyte layers by a biomimetic process; any particle can therefore be coated with silica since polyelectrolytes can be deposited beforehand via a layer-by-layer deposition method. Even after silanization, the SERS peaks of marker molecules on microAg particles are the only observable peaks since aliphatic polyelectrolytes, as well as silica shells, are intrinsically weak Raman scatterers, and more importantly, the SERS signals must be derived mostly from the first layer of the adsorbates (i.e., the marker molecules) in direct contact with the microAg particles. Silica shells, once fabricated, can further be derivatized to possess biofunctional groups; therefore, the modified microAg particles can be used as platforms of highly stable SERS-based biological sensors, as well as barcoding materials.

  7. Affine Fullerene C60 in a GS-Quasigroup

    Directory of Open Access Journals (Sweden)

    Vladimir Volenec


    Full Text Available It will be shown that the affine fullerene C60, which is defined as an affine image of buckminsterfullerene C60, can be obtained only by means of the golden section. The concept of the affine fullerene C60 will be constructed in a general GS-quasigroup using the statements about the relationships between affine regular pentagons and affine regular hexagons. The geometrical interpretation of all discovered relations in a general GS-quasigroup will be given in the GS-quasigroup C(1/2(1+5.

  8. Superintermolecular orbitals in the C60-pentacene complex (United States)

    Zhang, G. P.; Gardner, A.; Latta, T.; Drake, K.; Bai, Y. H.


    We report a group of unusually big molecular orbitals in the C60-pentacene complex. Our first-principles density-functional calculation shows that these orbitals are very delocalized and cover both C60 and pentacene, which we call superintermolecular orbitals (SIMOs). Their spatial extension can reach 1 nm or larger. Optically, SIMOs are dark. Different from ordinary unoccupied molecular orbitals, SIMOs have a very weak Coulomb and exchange interaction. Their energy levels are very similar to the native superatomic molecular orbitals in C60and can be approximately characterized by orbital angular momentum quantum numbers. They have a distinctive spatial preference. These features fit the key characters of charge-generation states that channel initially bound electrons and holes into free-charge carriers. Thus, our finding is important for C60-pentacene photovoltaics.

  9. Superintermolecular orbitals in the C$_{60}$/pentacene complex


    G.P. Zhang; Gardner, A.; Latta, T.; Drake, K.; Bai, Y. H.


    We report a group of unusually big molecular orbitals in the C60/pentacene complex. Our first-principles density functional calculation shows that these orbitals are very delocalized and cover both C60 and pentacene, which we call superintermolecular orbitals or SIMOs. Their spatial extension can reach 1 nm or larger. Optically, SIMOs are dark. Different from ordinary unoccupied molecular orbitals, SIMOs have a very weak Coulomb and exchange interaction. Their energy levels are very similar t...

  10. Fullerene antiferromagnetic reconstructed spinterface subsurface layer dominates multi-orbitals spin-splitting and large magnetic moment in C60

    CERN Document Server

    Shao, Yangfan; Pan, Hui; Shi, Xingqiang


    The interfaces between organic molecules and metal surfaces with layered antiferromagnetic order have gained increasing interests in the field of antiferromagnetic spintronics. The C60 layered AFM spinterfaces have been studied for C60 bonded only to the outermost ferromagnetic layer. Using density functional theory calculations, here we demonstrate that C60 adsorption can reconstruct the layered AFM Cr(001) surface so that C60 bonds to the top two Cr layers with opposite spin direction. Surface reconstruction drastically changes C60 s spintronic properties 1 the spin-split p-d hybridization involve multi-orbitals of C60 and metal double layers, 2 the subsurface layer dominates the C60 spin properties, and 3) reconstruction induces a large magnetic moment in C60 of 0.58 B, which is a synergetic effect of the top two layers as a result of a magnetic direct-exchange interaction. Understanding these complex spinterfaces phenomena is a crucial step for their device applications. The surface reconstruction can be ...

  11. Soil microbial response to photo-degraded C60 fullerenes. (United States)

    Berry, Timothy D; Clavijo, Andrea P; Zhao, Yingcan; Jafvert, Chad T; Turco, Ronald F; Filley, Timothy R


    Recent studies indicate that while unfunctionalized carbon nanomaterials (CNMs) exhibit very low decomposition rates in soils, even minor surface functionalization (e.g., as a result of photochemical weathering) may accelerate microbial decay. We present results from a C60 fullerene-soil incubation study designed to investigate the potential links between photochemical and microbial degradation of photo-irradiated C60. Irradiating aqueous (13)C-labeled C60 with solar-wavelength light resulted in a complex mixture of intermediate products with decreased aromaticity. Although addition of irradiated C60 to soil microcosms had little effect on net soil respiration, excess (13)C in the respired CO2 demonstrates that photo-irradiating C60 enhanced its degradation in soil, with ∼ 0.78% of 60 day photo-irradiated C60 mineralized. Community analysis by DGGE found that soil microbial community structure was altered and depended on the photo-treatment duration. These findings demonstrate how abiotic and biotic transformation processes can couple to influence degradation of CNMs in the natural environment.

  12. Phonons in A3C60 Lattice and Structural Dynamics

    Directory of Open Access Journals (Sweden)

    Sven Larsson


    Full Text Available The critical temperature ( of superconductivity in A3C60 compounds is generally lower smaller with alkali atoms (A. Furthermore decreases with applied pressure. In the BCS model, these trends are explained by the lower density of states at the Fermi level for a decreased lattice constant (R. There is more than one counterexample, however, suggesting that BCS does not give the whole truth. The most important one is that the compound with the largest lattice constant, Cs3C60, is not superconducting at all at ambient pressure. In this paper we derive a novel model where a negative lattice contribution to Hubbard U, proportional to 1/R, is taken into account. It is possible to explain why A3C60 compounds with A = Li, and Na have a low or are not superconducting at all, and why Cs3C60 is superconducting only at applied pressure and then with the highest of all C60 alkali fullerides. It is concluded that the density of states mechanism derived in the BCS model is in doubt. Nevertheless superconductivity in A3C60 depends on electron-phonon coupling. The dominating phonon is the bond stretching Ag phonon, a breathing phonon for the whole fullerene molecular ion.

  13. Dipole polarizability, sum rules, mean excitation energies, and long-range dispersion coefficients for buckminsterfullerene C 60 (United States)

    Kumar, Ashok; Thakkar, Ajit J.


    Experimental photoabsorption cross-sections combined with constraints provided by the Kuhn-Reiche-Thomas sum rule and the high-energy behavior of the dipole-oscillator-strength density are used to construct dipole oscillator strength distributions for buckminsterfullerene (C60). The distributions are used to predict dipole sum rules Sk, mean excitation energies Ik, the frequency dependent polarizability, and C6 coefficients for the long-range dipole-dipole interactions of C60 with a variety of atoms and molecules.

  14. Size, shape, and site selectivities in the photochemical reactions of molecules adsorbed on pentasil zeolites. Effects of coadsorbed water

    Energy Technology Data Exchange (ETDEWEB)

    Turro, N.J.; Cheng, C.; Abrams, L.; Corbin, D.R.


    The photochemistry of methylbenzyl benzyl ketones (ACOB) in the presence of pentasil zeolites follows strikingly different pathways due to the location of the adsorbed ketone. The product distribution, in terms of the cage effect (efficiency of germinate radical combination), demonstrates the effects of sorption and diffusion on the radical species produced by photolysis. p-ACOB is readily adsorbed within the pentasil framework and produces p-AB as the primary product. In contrast, the photolysis product distributions of o-ACOB can be dramatically varied depending upon the extent of its adsorption into the framework. By addition of a nonreactive titrant, such as water, after the ketone adsorption, the photolysis product distributions can be systematically varied depending upon the aluminum content of the framework. The observed results are completely described by considerations of (a) the size and shape sorption of the pentasil zeolites, (b) the sorption of water by the hydrophilic sites of the pentasil zeolites (which depend upon the framework aluminum content), and (c) the hydrophobic characteristics of the pentasil channels which do not contain framework aluminum.

  15. Surface-Enhanced Raman Spectroscopy of Dye and Thiol Molecules Adsorbed on Triangular Silver Nanostructures: A Study of Near-Field Enhancement, Localization of Hot-Spots, and Passivation of Adsorbed Carbonaceous Species

    Directory of Open Access Journals (Sweden)

    Manuel R. Gonçalves


    Full Text Available Surface-enhanced Raman spectroscopy (SERS of thiols and dye molecules adsorbed on triangular silver nanostructures was investigated. The SERS hot-spots are localized at the edges and corners of the silver triangular particles. AFM and SEM measurements permit to observe many small clusters formed at the edges of triangular particles fabricated by nanosphere lithography. Finite-element calculations show that near-field enhancements can reach values of more than 200 at visible wavelengths, in the gaps between small spherical particles and large triangular particles, although for the later no plasmon resonance was found at the wavelengths investigated. The regions near the particles showing strong near-field enhancement are well correlated with spatial localization of SERS hot-spots done by confocal microscopy. Silver nanostructures fabricated by thermal evaporation present strong and fast fluctuating SERS activity, due to amorphous carbon contamination. Thiols and dye molecules seem to be able to passivate the undesired SERS activity on fresh evaporated silver.

  16. Electron stimulated desorption of cations from C sub 6 H sub 6 and C sub 6 H sub 1 sub 2 molecules adsorbed on Pt(1 1 1) and Ar spacer layer

    CERN Document Server

    Kawanowa, H; Hanatani, K; Gotoh, Y; Souda, R


    Mechanisms of electron stimulated cation desorption have been investigated for adsorbed C sub 6 H sub 6 and C sub 6 H sub 1 sub 2 molecules on the Pt(1 1 1) surface and the Ar spacer layer formed on it. The ion yields from the molecules adsorbed on the Ar spacer layer are highly enhanced at the smallest coverage and decay steeply with increasing coverage. No such enhancement was observed when they are adsorbed directly on the Pt(1 1 1) substrate. This behavior is explained in terms of the Coulombic repulsion of cations confined in nanoclusters, together with the delocalization of valence holes on the Pt(1 1 1) substrate as well as in the multilayer hydrocarbons. The holes in the C sub 6 H sub 6 molecule are more delocalized than those in the C sub 6 H sub 1 sub 2 molecule due to the overlap of pi orbitals.

  17. Low-temperature scanning tunneling microscopy/ultraviolet photoelectron spectroscopy investigation of two-dimensional crystallization of C60: pentacence binary system on Ag(111) (United States)

    Lin Zhang, Jia; Hong Liang Zhang, Kelvin; Qiang Zhong, Jian; Chao Niu, Tian; Chen, Wei


    Atomic scale investigation of temperature-dependent two-dimensional (2 D) crystallization processes of fullerene-C60 on pentacene-covered Ag(111) surface has been carried out by in situ low-temperature scanning tunneling microscopy (LT-STM) experiments. To evaluate the effect of molecule-substrate interfacial interactions on the 2 D crystallization of C60: pentacene binary system, we also carried out the same self-assembly experiments of C60 on monolayer pentacene covered graphite substrate. It is revealed that temperature-dependent structural transition of various ordered C60 nanoassemblies is strongly influenced by the molecule-Ag(111) interfacial interactions, and further mediated by the weak C60-pentacene intermolecular interactions. In situ ultraviolet photoelectron spectroscopy (UPS) has been used to evaluate the nature of the intermolecular interactions between C60 and pentacene films.

  18. C60的氧化反应研究%Studies on Oxidation Reaction of C60

    Institute of Scientific and Technical Information of China (English)

    李旭; 孔庆宇; 等


    Two oxidation products of the reaction of C60 with O3 in toluene or dichlorobenzene were obtained in dependence on the amount of ozone absorbed by the solution and the reaction time. The short time oxidized product is insoluble in common organic solvents and water, but the water-soluble derivatives were obtained after hydrolysis under a basic condition. It′s IR spectrum is similar with that of C60 polyhydric derivatives. The extensive oxidation product of C60 is water-soluble without any further dispose. The structures of the two oxidized products were characterized by variable-temperature FTIR, XPS, elementary analysis, TGA and TOF-MS, ESI-MS, FAB-MS technique. Both products are thermally unstable, H2O, CO and CO2 are eliminated during the increase of temperature.%在C60的甲苯或二氯苯溶液中通入O3,通过改变O3的吸收量及反应时间可得到两种氧化产物. 一种产物在有机溶剂及水中均不溶,但经碱性水解后得到水溶性产物,其红外光谱与C60羟基化合物相似;在长时间通O3条件下,得到水溶性的C60氧化产物. 用变温红外光谱、 XPS、元素分析、热谱和质谱研究了氧化产物的可能结构,发现生成的C60氧化产物对热不稳定,随着温度升高,有CO2, CO和H2O放出.

  19. Supramolecular structures and photoelectronic properties of the inclusion complex of a cyclic free-base porphyrin dimer and C60. (United States)

    Nobukuni, Hirofumi; Shimazaki, Yuichi; Uno, Hidemitsu; Naruta, Yoshinori; Ohkubo, Kei; Kojima, Takahiko; Fukuzumi, Shunichi; Seki, Shu; Sakai, Hayato; Hasobe, Taku; Tani, Fumito


    A cyclic free-base porphyrin dimer H4-CPD(Py) (CPD = cyclic porphyrin dimer) linked by butadiyne moieties bearing 4-pyridyl groups self-assembles to form a novel porphyrin nanotube in the crystalline state. The cyclic molecules link together through nonclassical C-H⋅⋅⋅N hydrogen bonds and π–π interactions of the pyridyl groups along the crystallographic a axis. H4-CPD(Py) includes a C60 molecule in its cavity in solution. In the crystal structure of the inclusion complex (C60⊂H4-CPD(Py)), the dimer “bites” a C60 molecule by tilting the porphyrin rings with respect to each other, and there are strong π–π interactions between the porphyrin rings and C60. The included C60 molecules form a zigzag chain along the crystallographic b axis through van der Waals contacts with each other. Femtosecond laser flash photolysis of C60⊂H4-CPD(Py) in the solid state with photoexcitation at 420 nm shows the formation of a completely charge-separated state {H4-CPD(Py)·+ + C60·−}, which decays with a lifetime of 470 ps to the ground state. The charge-carrier mobility of the single crystal of C60⊂H4-CPD(Py) was determined by flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements. C60⊂H4-CPD(Py) has an anisotropic charge mobility (Σμ = 0.16 and 0.13 cm2 V(−1)  s(−1)) along the zigzag chain of C60 (which runs at 45° and parallel to the crystallographic b axis). To construct a photoelectrochemical cell, C60⊂H4-CPD(Py) was deposited onto nanostructured SnO2 films on a transparent electrode. The solar cell exhibited photovoltaic activity with an incident photon to current conversion efficiency of 17%.

  20. Nucleation of C60 on ultrathin SiO2 (United States)

    Conrad, Brad; Groce, Michelle; Cullen, William; Pimpinelli, Alberto; Williams, Ellen; Einstein, Ted


    We utilize scanning tunneling microscopy to characterize the nucleation, growth, and morphology of C60 on ultrathin SiO2 grown at room temperature. C60 thin films are deposited in situ by physical vapor deposition with thicknesses varying from <0.05 to ˜1 ML. Island size and capture zone distributions are examined for a varied flux rate and substrate deposition temperature. The C60 critical nucleus size is observed to change between monomers and dimers non-monotonically from 300 K to 500 K. Results will be discussed in terms of recent capture zone studies and analysis methods. Relation to device fabrication will be discussed. doi:10.1016/j.susc.2011.08.020

  1. Electrical conductivity of nanostructured and C60-modified aluminum

    NARCIS (Netherlands)

    Zameshin, A.; Popov, M.; Medvedev, V.V.; Perfilov, S.; Lomakin, R.; Buga, S.; Denisov, V.; Kirichenko, A.; Skryleva, E.; Tatyanin, E.; Aksenenkov, V.; Blank, V.


    In this paper, we study the electrical conductivity of nanostructured C60-modified aluminum, and the possibility of optimizing its electrical and mechanical properties. The model proposed allows estimating the electrical conductivity of the material at low surface filling factor. A number of samples

  2. Electrical conductivity of nanostructured and C-60-modified aluminum

    NARCIS (Netherlands)

    Zameshin, A.; Popov, M.; Medvedev, V.; Perfilov, S.; Lomakin, R.; Buga, S.; Denisov, V.; Kirichenko, A.; Skryleva, E.; Tatyanin, E.; Aksenenkov, V.; Blank, V.


    In this paper, we study the electrical conductivity of nanostructured C-60-modified aluminum, and the possibility of optimizing its electrical and mechanical properties. The model proposed allows estimating the electrical conductivity of the material at low surface filling factor. A number of sample

  3. Dynamics and phase transitions in A 1C 60 compounds (United States)

    Schober, H.; Renker, B.; Heid, R.; Tölle, A.


    We present an overview of extensive inelastic neutron scattering experiments carried out on powders of A 1C 60. The various phases leave strong fingerprints in the microscopic dynamics confirming the solid-state chemical reactions. The strong kinetic phase transitions can be followed in real time and turn out to be highly complex.

  4. Preparation of photovoltaic cells from sexithiophene-C-60 blends

    NARCIS (Netherlands)

    Veenstra, SC; Malliaras, GG; Brouwer, HJ; Esselink, FJ; Krasnikov, VV; vanHutten, PF; Wildeman, J; Jonkman, HT; Sawatzky, GA; Hadziioannou, G; Mohlmann, GR


    Large photovoltaic responses have been recently observed in devices based on conjugated polymer-C-60 blends. Their enhanced performance, which relies on the formation of a bicontinuous network of donor-acceptor heterojunctions, is very sensitive to the morphology of the blend. In this paper, we prop

  5. Electric Current Induced Light Emission from C60

    NARCIS (Netherlands)

    Palstra, T.T.M.; Haddon, R.C.; Lyons, K.B.


    We report the luminescence of C60 crystals and films due to the passage of an electrical current. The current-voltage behavior is highly non-linear with light-emission beyond a threshold voltage. The emission spectrum is featureless and resembles black-body radiation with an effective temperature on

  6. Investigation of optical limiting in C60 solution (United States)

    Joshi, M. P.; Mishra, S. R.; Rawat, H. S.; Mehendale, S. C.; Rustagi, K. C.


    Experimental and theoretical studies of optical limiting for 30 ns pulses at 527 nm in C60 are reported. The results indicate that the optical limiting action may involve contribution from other nonlinear loss mechanisms in addition to increased absorption from the photoexcited triplet state.

  7. Single crystals of fullerene (C60 makes organic thick film solar cells and self supporting organic solar cells possible.

    Directory of Open Access Journals (Sweden)

    M. Umeno


    Full Text Available Single crystals of Fullerene (SC-C60 were synthesized by simple liquid/liquid interface precipitation method. Organic thick film solar cell (with an active layer thickness of approximately 20 microns thick is demonstrated by combining SC-C60 with poly(3-octylthiophene. Our preliminary results indicate that organic thick film solar cells are possible; which were considered to be impossible due to low mobility and small exciton diffusion lengths in most of the organic materials including small organic molecules and conjugated conducting polymers. Further, SC-C60 seems to be promising materials for organic photovoltaics. Self supporting organic solar cell is also demonstrated using SC-C60.

  8. Oxygen-Induced Degradation in C60-Based Organic Solar Cells: Relation Between Film Properties and Device Performance. (United States)

    Bastos, João P; Voroshazi, Eszter; Fron, Eduard; Brammertz, Guy; Vangerven, Tim; Van der Auweraer, Mark; Poortmans, Jef; Cheyns, David


    Fullerene-based molecules are the archetypical electron-accepting materials for organic photovoltaic devices. A detailed knowledge of the degradation mechanisms that occur in C60 layers will aid in the development of more stable organic solar cells. Here, the impact of storage in air on the optical and electrical properties of C60 is studied in thin films and in devices. Atmospheric exposure induces oxygen-trap states that are 0.19 eV below the LUMO of the fullerene C60. Moreover, oxygen causes a 4-fold decrease of the exciton lifetime in C60 layers, resulting in a 40% drop of short-circuit current from optimized planar heterojunction solar cells. The presence of oxygen-trap states increases the saturation current of the device, resulting in a 20% loss of open-circuit voltage. Design guidelines are outlined to improve air stability for fullerene-containing devices.

  9. David Adler Lectureship Award Talk: Friction and energy dissipation mechanisms in adsorbed molecules and molecularly thin films (United States)

    Krim, Jacqueline


    Studies of the fundamental origins of friction have undergone rapid progress in recent years, with the development of new experimental and computational techniques for measuring and simulating friction at atomic length and time scales. The increased interest has sparked a variety of discussions and debates concerning the nature of the atomic-scale and quantum mechanisms that dominate the dissipative process by which mechanical energy is transformed into heat. Measurements of the sliding friction of physisorbed monolayers and bilayers can provide information on the relative contributions of these various dissipative mechanisms. Adsorbed films, whether intentionally applied or present as trace levels of physisorbed contaminants, moreover are ubiquitous at virtually all surfaces. As such, they impact a wide range of applications whose progress depends on precise control and/or knowledge of surface diffusion processes. Examples include nanoscale assembly, directed transport of Brownian particles, material flow through restricted geometries such as graphene membranes and molecular sieves, passivation and edge effects in carbon-based lubricants, and the stability of granular materials associated with frictional and frictionless contacts. Work supported by NSFDMR1310456.

  10. On the widths of Stokes lines in Raman scattering from molecules adsorbed at metal surfaces and in molecular conduction junctions (United States)

    Gao, Yi; Galperin, Michael; Nitzan, Abraham


    Within a generic model we analyze the Stokes linewidth in surface enhanced Raman scattering (SERS) from molecules embedded as bridges in molecular junctions. We identify four main contributions to the off-resonant Stokes signal and show that under zero voltage bias (a situation pertaining also to standard SERS experiments) and at low bias junctions only one of these contributions is pronounced. The linewidth of this component is determined by the molecular vibrational relaxation rate, which is dominated by interactions with the essentially bosonic thermal environment when the relevant molecular electronic energy is far from the metal(s) Fermi energy(ies). It increases when the molecular electronic level is close to the metal Fermi level so that an additional vibrational relaxation channel due to electron-hole (eh) exciton in the molecule opens. Other contributions to the Raman signal, of considerably broader linewidths, can become important at larger junction bias.

  11. In-plane X-ray diffraction study of the C-60/Au(110) p(6x5) reconstructed surface by direct methods

    NARCIS (Netherlands)

    Torrelles, X.; Rius, J.; Pedio, M.; Felici, R.; Rudolf, P.; Ferrer, S.; Miravitlles, C.; Alvarez, J.


    Adsorption of C60 on the highly anisotropic Au(110) 1 × 2 reconstructed surface leads to an ordered quasi hexagonal 6 × 5 superstructure. This interfacial reconstruction has been investigated by grazing incidence X-ray diffraction. Analysis of the in-plane data set reveals four C60 molecules per (6

  12. Silver nanoparticles sensitized C60(Ag@C60) as efficient electrocatalysts for hydrazine oxidation: Implication for hydrogen generation reaction (United States)

    Narwade, Shankar S.; Mulik, Balaji B.; Mali, Shivsharan M.; Sathe, Bhaskar R.


    Herein, we report the synthesis of silver nanoparticles (Ag NPs; 10 ± 0.5 nm) sensitized Fullerene (C60; 15 ±2 nm) nanocatalysts (Ag@C60) for the first time showing efficient electroatalytic activity for the oxidation of hydrazine demonstrating activity comparable to that of Pt in acidic, neutral and basic media. The performance is comparable with the best available electrocatalytic system and plays a vital role in the overall hydrogen generation reactions from hydrazine as a one of the fuel cell reaction. The materials are synthesized by a simple and scalable synthetic route involving acid functionalization of C60 followed by chemical reduction of Ag+ ions in ethylene glycol at high temperature. The distributation of Silver nanoparticles (Ag NPs) (morphological information) on C60, bonding, its crystal structure, along with activity towards hydrazine oxidation (electrocatalytic) is studied using TEM, XRD, UV-vis, XPS, FTIR and electrochemical (cyclic voltammetry) studies, respectively. The observed efficient electrocatalytic activity of the as-synthesized electrode is attributed to the co-operative response and associated structural defects due to their oxidative functionalization along with thier cooperative functioning at nanodimensions.

  13. Kramers-Kronig relation between nonlinear absorption and refraction of C(60) and C(70). (United States)

    Wu, Chen-Cheng; Liu, Tai-Min; Wei, Tai-Ying; Xin, Li; Li, Yi-Ci; Lee, Li-Shu; Chang, Che-Kai; Tang, Jaw-Luen; Yang, Sidney S; Wei, Tai-Huei


    Using the Z-scan technique with 532 nm 16 picosecond laser pulses, we observe reverse saturable absorption and positive nonlinear refraction of toluene solutions of both C(60) and C(70). By deducting the positive Kerr nonlinear refraction of the solvent, we notice that the solute molecules contribute to nonlinear refraction of opposite signs: positive for C(60) and negative for C(70). Attributing nonlinear absorption and refraction of both solutes to cascading one-photon excitations, we illustrate that they satisfy the Kramers-Kronig relation. Accordingly, we attest the signs and magnitudes of nonlinear refraction for both solutes at 532 nm by Kramers-Kronig transform of the corresponding nonlinear absorption spectra.

  14. ECSTM study of adsorption of C60,C70,C86 and Y@C82 on Au(111)

    Institute of Scientific and Technical Information of China (English)


    The adsorption of a variety of fullerenes (C60,C70,C86,Y@C82) on Au(111) electrode surfaces was comprehensively investigated in 0.1 M HClO4 by electrochemical scanning tunneling microscopy (ECSTM).In the ordered C60’s adlayer,C60 molecules formed either (2(1/3) × 2 3~(1/3))or "in-phase" structure.The high resolution STM image shows that the C60 cage is not simply round but shows a bifurcated feature.The adsorption orientation of C60 on Au(111) is tentatively suggested.In the ordered C70’s adlayer,the perpendicular fullerene molecules are the main adsorption mode and form (2 3~(1/3) × 2 3~(1/3)) structure.However,for C86 and Y@C82,the ordered adlayer could not be obtained on Au(111) under the present condition.These differences may be due to the different molecular shapes and sizes,and the encapsulated metal atom which affects the lattice matches with the substrate.The adsorption of fullerene molecules on Au(111) from disorder to order could be tuned simply by steering the dimensional sizes or shapes of the fullerenes used.

  15. Single molecule detection of nitric oxide enabled by d(AT)15 DNA adsorbed to near infrared fluorescent single-walled carbon nanotubes. (United States)

    Zhang, Jingqing; Boghossian, Ardemis A; Barone, Paul W; Rwei, Alina; Kim, Jong-Ho; Lin, Dahua; Heller, Daniel A; Hilmer, Andrew J; Nair, Nitish; Reuel, Nigel F; Strano, Michael S


    We report the selective detection of single nitric oxide (NO) molecules using a specific DNA sequence of d(AT)(15) oligonucleotides, adsorbed to an array of near-infrared fluorescent semiconducting single-walled carbon nanotubes (AT(15)-SWNT). While SWNT suspended with eight other variant DNA sequences show fluorescence quenching or enhancement from analytes such as dopamine, NADH, L-ascorbic acid, and riboflavin, d(AT)(15) imparts SWNT with a distinct selectivity toward NO. In contrast, the electrostatically neutral polyvinyl alcohol enables no response to nitric oxide, but exhibits fluorescent enhancement to other molecules in the tested library. For AT(15)-SWNT, a stepwise fluorescence decrease is observed when the nanotubes are exposed to NO, reporting the dynamics of single-molecule NO adsorption via SWNT exciton quenching. We describe these quenching traces using a birth-and-death Markov model, and the maximum likelihood estimator of adsorption and desorption rates of NO is derived. Applying the method to simulated traces indicates that the resulting error in the estimated rate constants is less than 5% under our experimental conditions, allowing for calibration using a series of NO concentrations. As expected, the adsorption rate is found to be linearly proportional to NO concentration, and the intrinsic single-site NO adsorption rate constant is 0.001 s(-1) μM NO(-1). The ability to detect nitric oxide quantitatively at the single-molecule level may find applications in new cellular assays for the study of nitric oxide carcinogenesis and chemical signaling, as well as medical diagnostics for inflammation.

  16. Performance of the TPSS Functional on Predicting Core Level Binding Energies of Main Group Elements Containing Molecules: A Good Choice for Molecules Adsorbed on Metal Surfaces. (United States)

    Pueyo Bellafont, Noèlia; Viñes, Francesc; Illas, Francesc


    Here we explored the performance of Hartree-Fock (HF), Perdew-Burke-Ernzerhof (PBE), and Tao-Perdew-Staroverov-Scuseria (TPSS) functionals in predicting core level 1s binding energies (BEs) and BE shifts (ΔBEs) for a large set of 68 molecules containing a wide variety of functional groups for main group elements B → F and considering up to 185 core levels. A statistical analysis comparing with X-ray photoelectron spectroscopy (XPS) experiments shows that BEs estimations are very accurate, TPSS exhibiting the best performance. Considering ΔBEs, the three methods yield very similar and excellent results, with mean absolute deviations of ∼0.25 eV. When considering relativistic effects, BEs deviations drop approaching experimental values. So, the largest mean percentage deviation is of 0.25% only. Linear trends among experimental and estimated values have been found, gaining offsets with respect to ideality. By adding relativistic effects to offsets, HF and TPSS methods underestimate experimental values by solely 0.11 and 0.05 eV, respectively, well within XPS chemical precision. TPSS is posed as an excellent choice for the characterization, by XPS, of molecules on metal solid substrates, given its suitability in describing metal substrates bonds and atomic and/or molecular orbitals.

  17. Optical and electronic properties of SO2 molecule adsorbed on Si-doped (8, 0) boron nitride nanotube (United States)

    Guo, Shuang-Shuang; Wei, Xiu-Mei; Zhang, Jian-Min; Zhu, Gang-Qiang; Guo, Wan-Jin


    The study of the optical properties of pristine BNNT, Si-doped BNNTs and SO2 molecule adsorption on Si-doped BNNTs is that, to our knowledge, few relevant research have ever been found. In this paper, the adsorption behaviors of Sulfur dioxide (SO2) molecule on Si-doped Boron nitride nanotubes (BNNTs) are investigated applying the first-principles calculations. The main contribution of this paper is that the foremost investigation for the optical properties of the pristine BNNT, Si-doped BNNTs and SO2 adsorption on Si-doped BNNTs. Additionally, the electronic properties and the structural properties are also presented. In our calculations of optical properties, the dielectric constant, the refractive index and the absorption coefficient are obtained. Comparing the pristine BNNT, our results indicate that, the blue-shifts (in the main peaks of the dielectric constant of SiB -BNNT and SO2-SiB -BNNT), and the red-shifts (in the main peaks of the refractive index of SiN -BNNT and SO2-SiN -BNNT) are appeared. Under these conditions, Si-doped BNNT and Si-doped BNNT with SO2 adsorption, the gaps are reduced both for the speculated optical band gaps and the electronic structure band gaps.

  18. C60-based clustering scheme for sensor management in STSS

    Institute of Scientific and Technical Information of China (English)

    Yiyu Zhou


    Clustering-based sensor-management schemes have been widely used for various wireless sensor networks (WSNs), as they are wel suited to the distributive and col aborative nature of WSN. In this paper, a C60-based clustering algorithm is proposed for the specific planned network of space tracking and surveil ance system (STSS), where al the sensors are partitioned into 12 clus-ters according to the C60 (or footbal surface) architecture, and then a hierarchical sensor-management scheme is wel designed. Final y, the algorithm is applied to a typical STSS constel ation, and the simulation results show that the proposed method has bet-ter target-tracking performance than the nonclustering scheduling method.

  19. La estructura del fullereno C60 y sus aplicaciones




    Se revisan los datos reportados de una nueva clase de materiales basados en los fullerenos. Se explica la estructura del fullereno C60 y sus compuestos con metales alcalinos, sus propiedades y aplicaciones. Se señala que estos compuestos tienen propiedades de superconducción comparable con la de los tradicionales cupratos. Se indica que esta modificación del carbono puede formar nanotubos que tienen varias aplicaciones prácticas debido a sus propiedades.

  20. New Ruthenium Complexes of Fullerene C60&C70

    Institute of Scientific and Technical Information of China (English)


    The new complexes [Ru(NO)(PPh3)]2(η2-Cm)(m=60 1 or 70 2) have been prepared by heating a solution of C60(or C70) with [Ru(NO)2(PPh3)2] in toluene. They have been characterized by elemental analysis, IR, UV/VIS, XPS, 13C and 31P NMR spectroscopy. The photovaltaic effect for the new compounds has been studied.

  1. Strong spin-filtering and spin-valve effects in a molecular V–C60–V contact

    Directory of Open Access Journals (Sweden)

    Mohammad Koleini


    Full Text Available Motivated by the recent achievements in the manipulation of C60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111 surface using first-principles calculations. For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%. Moreover, we find a significant change in the conductance between parallel and anti-parallel spin polarizations in the junction (86% which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems.

  2. Synthesis and Characterization of Fullerene Nanowhiskers by Liquid-Liquid Interfacial Precipitation: Influence of C60 Solubility

    Directory of Open Access Journals (Sweden)

    Marappan Sathish


    Full Text Available Fullerene nanowhiskers (FNWs composed of C60 fullerene molecules were prepared using the liquid–liquid interfacial precipitation (LLIP method in the carbon-disulfide (CS2 and isopropyl alcohol (IPA system. The electron microscopic images reveal the formation of non-tubular FNWs. The X-ray diffraction (XRD pattern studies indicate the presence of fcc crystalline structure and unusual triclinic structure in the FNWs. The selected area electron diffraction pattern (SAED analysis demonstrates the existence of triclinic and electron beam assisted fcc to tetragonal crystalline phase transformation. The formation of triclinic structure might be validated due to the partial polymerization of FNWs at C60 saturated CS2-IPA interface. The high solubility of C60 in CS2 solvent system results in partial polymerization of FNWs. The polymerization of fullerene molecules in the FNWs has been further confirmed using Raman spectroscopy.

  3. Photoionization and photofragmentation of the C60+ molecular ion (United States)

    Baral, K. K.; Aryal, N. B.; Esteves-Macaluso, D. A.; Thomas, C. M.; Hellhund, J.; Lomsadze, R.; Kilcoyne, A. L. D.; Müller, A.; Schippers, S.; Phaneuf, R. A.


    Cross-section measurements are reported for single and double photoionization of C60+ ions in the photon energy range 18-150 eV accompanied by the loss of zero to seven pairs of carbon atoms, as well as for fragmentation without ionization resulting in loss of two to eight pairs of C atoms in the photon energy range 18-65 eV. Absolute measurements were performed by merging a beam of C60+ molecular ions with a beam of monochromatized synchrotron radiation. Product channels involving dissociation yielding smaller fullerene fragment ions account for nearly half of the total measured oscillator strength in this energy range. The sum of cross sections for the measured product channels is compared to a published calculation of the total photoabsorption cross section of neutral C60 based on time-dependent density-functional theory. This comparison and an accounting of oscillator strengths indicate that with the exception of C58+, the most important product channels resulting from photoabsorption were accounted for in the experiment. Threshold energies for the successive removal of carbon atom pairs accompanying photoionization are also determined from the measurements.

  4. Fabrication of C 60 nanostructures by selective growth on GaSe/MoS 2 and InSe/MoS 2 heterostructure substrates (United States)

    Ueno, Keiji; Sasaki, Kentaro; Nakahara, Tomonori; Koma, Atsushi


    C 60 molecules were deposited on a submonolayer InSe film which was grown on a MoS 2 substrate. In the previous experiment on the growth of a C 60 thin film on a GaSe/MoS 2 heterostructure, C 60 grew only on exposed MoS 2 regions and never nucleated on GaSe domains at substrate temperature above 180°C. In the present case, however, C 60 molecules grow only on InSe domains and do not nucleate on the exposed MoS 2 when the substrate temperature is higher than 80°C. Using this method, C 60 domains whose dimension is smaller than 100 nm could be fabricated on each InSe domain. The selectivity of the C 60 growth is supposed to originate not from the surface morphology of those heterostructures, but from the difference in adsorption energy and surface diffusion energy of C 60 molecules on the surfaces of three different layered materials and a C 60 film.

  5. Electronic Correlations, Jahn-Teller Distortions and Mott Transition to Superconductivity in Alkali-C60 Compounds

    Directory of Open Access Journals (Sweden)

    Alloul H.


    Full Text Available The discovery in 1991 of high temperature superconductivity (SC in A3C60 compounds, where A is an alkali ion, has been rapidly ascribed to a BCS mechanism, in which the pairing is mediated by on ball optical phonon modes. While this has lead to consider that electronic correlations were not important in these compounds, further studies of various AnC60 with n=1, 2, 4 allowed to evidence that their electronic properties cannot be explained by a simple progressive band filling of the C60 six-fold degenerate t1u molecular level. This could only be ascribed to the simultaneous influence of electron correlations and Jahn-Teller Distortions (JTD of the C60 ball, which energetically favour evenly charged C60 molecules. This is underlined by the recent discovery of two expanded fulleride Cs3C60 isomeric phases which are Mott insulators at ambient pressure. Both phases undergo a pressure induced first order Mott transition to SC with a (p, T phase diagram displaying a dome shaped SC, a common situation encountered nowadays in correlated electron systems. NMR experiments allowed us to study the magnetic properties of the Mott phases and to evidence clear deviations from BCS expectations near the Mott transition. So, although SC involves an electron-phonon mechanism, the incidence of electron correlations has an importance on the electronic properties, as had been anticipated from DMFT calculations.

  6. A theoretical study of the XP and NEXAFS spectra of alanine: gas phase molecule, crystal, and adsorbate at the ZnO(10 ̅10) surface. (United States)

    Gao, You Kun; Traeger, Franziska; Kotsis, Konstantinos; Staemmler, Volker


    The adsorption of alanine on the mixed-terminated ZnO(10 ̅10) surface is studied by means of quantum-chemical ab initio calculations. Using a finite cluster model and the adsorption geometry as obtained both by periodic CPMD and embedded cluster calculations, the C1s, N1s and O1s X-ray photoelectron spectra (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra are calculated for single alanine molecules on ZnO(10 ̅10). These spectra are compared with the spectra calculated for alanine in the gas phase and in its crystalline form and with experimental XPS and NEXAFS data for the isolated alanine molecule and for alanine adsorbed on ZnO(10 ̅10) at multilayer and monolayer coverage. The excellent agreement between the experimental and calculated XP and NEXAFS spectra confirms the calculated adsorption geometry: A single alanine molecule is bound to ZnO(10 ̅10) in a dissociated bidentate form with the two O atoms of the acid group bound to two Zn atoms of the surface and the proton transferred to one O atom of the surface. Other possible structures, such as adsorption of alanine in one of its neutral or zwitterionic forms in which the proton of the -COOH group remains at this group or is transferred to the amino group, can be excluded since they would give rise to quite different XP spectra. In the multilayer coverage regime, on the other hand, alanine is in its crystalline form as is also shown by the analysis of the XP spectra.

  7. Determination of the sputtering yield of cholesterol using Arn(+) and C60(+(+)) cluster ions. (United States)

    Rakowska, P D; Seah, M P; Vorng, J-L; Havelund, R; Gilmore, I S


    The sputtering yield of cholesterol films on silicon wafers is measured using Arn(+) and C60(+(+)) ions in popular energy (E) and cluster size (n) ranges. It is shown that the C60(+(+)) ions form a surface layer that stabilizes the film so that a well-behaved profile is obtained. On the other hand, the Arn(+) gas clusters leave the material very clean but, at room temperature, the layer readily restructures into molecular bilayers, so that, although a useful measure may be made of the sputtering yield, the profiles become much more complex. This restructuring does not occur at room temperature normally but results from the actions of the beams in the sputtering process for profiling in secondary ion mass spectrometry. Better profiles may be made by reducing the sample temperature to -100 °C. This is likely to be necessary for many lower molecular weight materials (below 1000 Da) to avoid the movement of molecules. Measurements for cholesterol films on 37 nm of amiodarone on silicon are even better behaved and show the same sputtering yields at room temperature as those films directly on silicon at -100 °C. The yields for both C60(+(+)) and Arn(+) fit the Universal Equation to a standard deviation of 11%.

  8. Morphology Change of C60 Islands on Organic Crystals Observed by Atomic Force Microscopy. (United States)

    Freund, Sara; Hinaut, Antoine; Pawlak, Rémy; Liu, Shi-Xia; Decurtins, Silvio; Meyer, Ernst; Glatzel, Thilo


    Organic-organic heterojunctions are nowadays highly regarded materials for light-emitting diodes, field-effect transistors, and photovoltaic cells with the prospect of designing low-cost, flexible, and efficient electronic devices.1-3 However, the key parameter of optimized heterojunctions relies on the choice of the molecular compounds as well as on the morphology of the organic-organic interface,4 which thus requires fundamental studies. In this work, we investigated the deposition of C60 molecules at room temperature on an organic layer compound, the salt bis(benzylammonium)bis(oxalato)cupurate(II), by means of noncontact atomic force microscopy. Three-dimensional molecular islands of C60 having either triangular or hexagonal shapes are formed on the substrate following a "Volmer-Weber" type of growth. We demonstrate the dynamical reshaping of those C60 nanostructures under the local action of the AFM tip at room temperature. The dissipated energy is about 75 meV and can be interpreted as the activation energy required for this migration process.

  9. Study of C60/Au(110)-p(6 × 5) Reconstruction from In-Plane X-Ray Diffraction Data

    NARCIS (Netherlands)

    Pedio, M.; Felici, R.; Torrelles, X.; Rudolf, P.; Capozi, M.; Rius, J.; Ferrer, S.


    Fullerene molecules absorbed on the highly anisotropic Au(110)-p(1 × 2) surface induce an ordered p(6 × 5) superstructure that has been solved by applying the 2D “direct methods” difference sum function to the surface x-ray diffraction data set. We found that the C60-gold interface is structurally m

  10. Modeling adsorption: Investigating adsorbate and adsorbent properties (United States)

    Webster, Charles Edwin


    Surface catalyzed reactions play a major role in current chemical production technology. Currently, 90% of all chemicals are produced by heterogeneously catalyzed reactions. Most of these catalyzed reactions involve adsorption, concentrating the substrate(s) (the adsorbate) on the surface of the solid (the adsorbent). Pore volumes, accessible surface areas, and the thermodynamics of adsorption are essential in the understanding of solid surface characteristics fundamental to catalyst and adsorbent screening and selection. Molecular properties such as molecular volumes and projected molecular areas are needed in order to convert moles adsorbed to surface volumes and areas. Generally, these molecular properties have been estimated from bulk properties, but many assumptions are required. As a result, different literature values are employed for these essential molecular properties. Calculated molar volumes and excluded molecular areas are determined and tabulated for a variety of molecules. Molecular dimensions of molecules are important in the understanding of molecular exclusion as well as size and shape selectivity, diffusion, and adsorbent selection. Molecular dimensions can also be used in the determination of the effective catalytic pore size of a catalyst. Adsorption isotherms, on zeolites, (crystalline mineral oxides) and amorphous solids, can be analyzed with the Multiple Equilibrium Analysis (MEA) description of adsorption. The MEA produces equilibrium constants (Ki), capacities (ni), and thermodynamic parameters (enthalpies, ΔHi, and entropies, ΔSi) of adsorption for each process. Pore volumes and accessible surface areas are calculated from the process capacities. Adsorption isotherms can also be predicted for existing and new adsorbate-adsorbent systems with the MEA. The results show that MEA has the potential of becoming a standard characterization method for microporous solids that will lead to an increased understanding of their behavior in gas

  11. Organic field effect transistor composed by fullerene C60 and heterojunctions (United States)

    Vasconcelos, Railson C.; Aleixo, Vicente F. P.; Del Nero, Jordan


    We present a study of the complex electronic behavior of a fullerene (C60) molecule attached to six leads (heterojunctions), which works as a three-dimension rectifier. In addition, we confirmed that the fullerene works not only as an electron donor, but also as barrier and transport channel to electrons through the molecule. Moreover, when the phenylpropanodinilla (PPP) lead is orthogonally subjected to bias voltage, the charge distribution and the current displays regions of saturation and resonance similar to semiconductor devices. In order to understand the electronic transport in the molecule, we applied non-equilibrium green function (NEGF) method and performed Fowler-Nordheim (FN) and Millikan-Lauritsen (ML) analyses. The ML curves proved to be sufficient to describe the FN characteristics. In this work, we report the theoretical design for electronic transport of a 3D device (6-terminal).

  12. Molecular terms, magnetic moments, and optical transitions of molecular ions C60mplus-or-minus (United States)

    Nikolaev, A. V.; Michel, K. H.


    Starting from a multipole expansion of intramolecular Coulomb interactions, we present configuration interaction calculations of the molecular energy terms of the hole configurations (hu)+m, m=2-5, of C60m+ cations, of the electron configurations t1un, n=2-4, of the C60n- anions, and of the exciton configurations (hu+t1u)-, (hu+t1g)- of the neutral C60 molecule. The ground state of C602- is either 3T1g or 1Ag, depending on the energy separation between t1g and t1u levels. There are three close (approx0.03 eV) low lying spin triplets 3T1g, 3Gg, 3T2g for C602+, and three spin quartets 4T1u, 4Gu, 4T2u for C603+, which can be subjected to the Jahn-Teller effect. The number of low lying nearly degenerate states is largest for m=3 holes. We have calculated the magnetic moments of the hole and electron configurations and found that they are independent of molecular orientation with respect to an external magnetic field. The coupling of spin and orbital momenta differs from the atomic case. We analyze the electronic dipolar transitions (t1u)2[right arrow] t1ut1g and (t1u)3 [right arrow](t1u)2t1g for C602- and C603-. Three optical absorption lines (3T1g[right arrow] 3Hu, 3T1u, 3Au) are found for the ground level of C602- and only one line (4Au[right arrow]4T1g) for the ground state of C603-. We compare our results with the experimental data for C60n- in solutions and with earlier theoretical studies.

  13. DC Characterisation of C60 Whiskers and Nanowhiskers

    DEFF Research Database (Denmark)

    Larsson, Michael; Kjelstrup-Hansen, Jakob; Lucyszyn, Stepan


    C60 whiskers exhibit increasing conductivity with decreasing diameter. At diameters of 1 mm and below, a single-crystal structure predominates, and enhanced electrical characteristics are expected; however, no supporting data exists in the literature. Here, results of four-point probe measurements......, indicating strong potential for use in organic electronic applications of the future. Repeated current cycling in air is observed to promote sample degradation, possibly due to progressive oxidation of the carbon structure. A micromachined four-point probe is also used to try to establish non...

  14. Metal-Insulator Transition in C60-Polymers

    CERN Document Server

    Harigaya, K


    Variations in the band structures of C60-polymers are studied, when pi-conjugation conditions are changed. We look at band structures in order to discuss a metal-insulator transition, using a semi-empirical model with the Su-Schrieffer-Heeger type electron-phonon interactions. We find that electronic structures change among direct-gap insulators and the metal, depending on the degree of pi-conjugations. High pressure experiments could observe such pressure-induced metal-insulator transitions.

  15. Self-assembled C60 layers on incommensurate Cu/Si(111)'pseudo-5 × 5' surface (United States)

    Olyanich, D. A.; Mararov, V. V.; Utas, T. V.; Zotov, A. V.; Saranin, A. A.


    Self-assembled growth of C60 monolayers on the pristine and Ge-modified Cu/Si(111)'pseudo-5 × 5' surfaces was studied using scanning tunneling microscopy observations. The pristine Cu/Si(111)'pseudo-5 × 5' surface shows up as an incommensurate reconstruction on Si(111) substrate, while Ge-modified surface shows up as an array of Ge atomic clusters grown on the Cu/Si(111)'pseudo-5 × 5' template. It has been found that C60 fullerenes are highly mobile on the both surfaces, hence at the early growth stages fullerenes are accumulated along the atomic steps forming their quasi-one-dimensional molecular stripes. With further C60 deposition, almost ideal two-dimensional close-packed molecular monolayers are formed. The layers are modulated as evidenced by developing quasi-periodic pattern of dim and bright fullerenes displaying 2 × 2 periodicity. Contrast difference between dim and bright fullerenes is supposed to have a topographical origin, namely, bright fullerenes reside higher than dim fullerenes. Dim fullerenes were concluded to occupy centers of hexagons which constitute honeycomb-like structure of the Cu/Si(111)'pseudo-5 × 5' surface. For the Ge-modified surface, this means that adsorbing C60 fullerenes displace Ge atoms from their original positions to the interstitial sites in the molecular monolayer. Ge atoms were found to terminate rotational motion of selected fullerenes in the layer.

  16. Synthesis of mesogenic phthalocyanine-C60 donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

    Directory of Open Access Journals (Sweden)

    Yves Henri Geerts


    Full Text Available A series of phthalocyanine-C60 dyads 2a–d was synthesized. Key steps in their synthesis are preparation of the low symmetry phthalocyanine intermediate by the statistical condensation of two phthalonitriles, and the final esterification of the fullerene derivative bearing a free COOH group. Structural characterization of the molecules in solution was performed by NMR spectroscopy, UV–vis spectroscopy and cyclic voltammetry. Preliminary studies suggest formation of liquid crystalline (LC mesophases for some of the prepared dyads. To the best of our knowledge, this is the first example of LC phthalocyanine-C60 dyads.

  17. Eigenvectors of internal vibrations of C60: Theory and experiment (United States)

    Heid, R.; Pintschovius, L.; Godard, J. M.


    We have studied the eigenvectors of all internal modes of C60 up to 75 meV by inelastic neutron scattering. The experimental data are compared in detail with a state-of-the-art ab initio theory and a phenomenological model of the vibrational spectrum of C60, respectively. We demonstrate that the momentum dependence of mode intensities obtained from measurements on single crystals as well as on powder samples represents a sensitive fingerprint of the eigenvectors which allows (i) unambiguous assignments of silent modes and (ii) discrimination of eigenvectors of modes belonging to the same symmetry class. The latter property can be used for stringent tests of theoretical models. Eigenvectors predicted by the ab initio theory are found to be in very satisfactory agreement with the experimental data, while those obtained from the phenomenological model turn out to be less reliable. We have also performed measurements to study the dispersion of the Hg(1) mode in the low-temperature phase. We found that the data can be largely, although not fully, understood on the basis of a simple van der Waals ansatz for the intermolecular interactions.

  18. Collision of low energy Na+ ion with C60

    Institute of Scientific and Technical Information of China (English)


    The collision-induced reaction of Na+ ion with neutral C6o vapour was investigated at the energy range of 10 to 150 eV. The deposited films were studied via laser desorption time-of-flight mass spectroscopy (TOFMS). The fragment products of C60 with even number of carbon atoms, such as Cn+ (n=58, 56, 54), and adduct products, such as Cn+ (n=62, 64, 66, 68) were obser.vcd in the positively charged TOF mass spectra. The endohedral fullerene ion of Na@C60+ was detected when collision energies are above 20 eV. Besides, no negative endohedral fullerene was detected, the products appearing in positively charged mass spectra were also observed in the negatively charged mass spectra. In addition, a series of products with odd number of carbon atoms, such as Cn- (n=53, 55, 57, 59, 61, 63, 65, 67), also appeared, but the intensities of their signals were not as high as that of even numbered. Finally, it is interesting to find that the deposited films are insoluable in toluene, benzene or water. Their Fourier transform infrared (FTIR) spectra seem like those photopolymerized ones. Some of the reaction schemes are proposed to explain the experimental results.

  19. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations. (United States)

    Meng, Qingyong; Meyer, Hans-Dieter


    Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed.

  20. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingyong, E-mail: [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China); Meyer, Hans-Dieter, E-mail: [Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)


    Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed.

  1. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules. (United States)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao


    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g(-1) for catechol and 736.8 μmol g(-1) for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6-101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples.

  2. Continuum modeling investigation of gigahertz oscillators based on a C60 fullerene inside cyclic peptide nanotubes (United States)

    Sadeghi, F.; Ansari, R.; Darvizeh, M.


    Research concerning the fabrication of nano-oscillators with operating frequency in the gigahertz (GHz) range has become a focal point in recent years. In this paper, a new type of GHz oscillators is introduced based on a C60 fullerene inside a cyclic peptide nanotube (CPN). To study the dynamic behavior of such nano-oscillators, using the continuum approximation in conjunction with the 6-12 Lennard-Jones (LJ) potential function, analytical expressions are derived to determine the van der Waals (vdW) potential energy and interaction force between the two interacting molecules. Employing Newton's second law, the equation of motion is solved numerically to arrive at the telescopic oscillatory motion of a C60 fullerene inside CPNs. It is shown that the fullerene molecule exhibits different kinds of oscillation inside peptide nanotubes which are sensitive to the system parameters. Furthermore, for the precise evaluation of the oscillation frequency, a novel semi-analytical expression is proposed based on the conservation of the mechanical energy principle. Numerical results are presented to comprehensively study the effects of the number of peptide units and initial conditions (initial separation distance and velocity) on the oscillatory behavior of C60 -CPN oscillators. It is found out that for peptide nanotubes comprised of one unit, the maximum achievable frequency is obtained when the inner core oscillates with respect to its preferred positions located outside the tube, while for other numbers of peptide units, such frequency is obtained when the inner core oscillates with respect to the preferred positions situated in the space between the two first or the two last units. It is further found out that four peptide units are sufficient to obtain the optimal frequency.

  3. On interface dipole layers between C60 and Ag or Au

    NARCIS (Netherlands)

    Veenstra, Sjoerd; Heeres, A.; Hadziioannou, G.; Sawatzky, G.A.; Jonkman, H.T.


    C60 layers on polycrystalline Ag and Au are studied by photoelectron spectroscopy. At these metal/C60 interfaces an electron transfer occurs from the metal to the lowest unoccupied orbital of C60. We found in the case of the polycrystalline Ag/C60 interface a dipolar layer with its associated electr

  4. The role of humic acid in stabilizing fullerene (C60) suspensions%腐殖酸对富勒烯C60的悬浮作用

    Institute of Scientific and Technical Information of China (English)

    Lu-qing ZHANG; Yu-kun ZHANG; Xiu-chun LIN; Kun YANG; Dao-hui LIN


    Natural organic matter (NOM) has a profound effect on the colloidal stability of discharged C60 nanoparticles in the water environment, which influences the environmental behaviors and risks of C60 and therefore merits more specific studies. This study investigates the effects of humic acid (HA), as a model NOM, on the aqueous stabilization of C60 powder and the colloidal stability of a previously suspended C60 suspension (aqu/nC60) with variations of pH values and ionic strengths. Our results reveal that HA could disperse C60 powder in water to some degree, but was unable to stably suspend them. The aqu/nC60 could remain stable at pH>4 but was destabilized at lower pH values. However, the colloidal stability of aqu/nC60 in the presence of HA was insensitive to pH 3-11, owing to the adsorption of HA onto nC60 and the increased electrosteric repulsions among nC60 aggregates. The colloidal stability of aqu/nC60, with and without HA, decreased as we increased the valence and concentration of the added cations. HA was found to mitigate the destabilization effect of Na+on the colloidal stability of aqu/nC60 by increasing the critical coagulation concentration (CCC) of Na+, while HA lowered the CCCs of Ca2+and La3+probably by the bridging effect of nC60 with HA aggregates formed through the intermolecular bridging of the HA macromolecules via cation complexation at high concentrations of cations with high valences.%研究目的:腐殖酸(HA)对富勒烯(C60)粉末的悬浮作用以及pH、离子强度对HA-C60悬浮性能的影响。  创新要点:研究水质条件对C60悬浮性能的影响。  研究方法:测定C60粉末在HA溶液中的zeta电位,水力学粒径和悬浮浓度;HA存在下,C60悬浮体系的zeta电位与水力学粒径随pH的变化及C60悬浮体系团聚动力学随离子强度的变化。  重要结论:HA对C60粉末起到一定的分散作用,但不能使其长时间稳定悬浮于水中。当pH<4时,C60

  5. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao, E-mail:


    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g{sup −1} for catechol and 736.8 μmol g{sup −1} for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols.

  6. In situ observation of C60(C(COOH)2)2 interacting with living cells using fluorescence microscopy

    Institute of Scientific and Technical Information of China (English)

    YE Chang; ZHAO Yuliang; CHAI Zhifang; FANG Xiaohong; HAN Dong; CHEN Long; WANG Chen; WEI Taotao; CHEN Chunying; CHEN Zhen; MENG Huan; XING Li; JIANG Yaxin; YUAN Hui; XING Gengmei; ZHAO Feng


    The interactions between nanoparticles and living cells were investigated by an imaging technique of fluorescence microscopy. For this purpose, the C60 derivative C60(C(COOH)2)2, a therapeutic agent for degeneration diseases of central nervous system, was synthesized, purified and characterized. Its interaction with the living cell and penetration of the cellular membrane were in situ studied using the real time imaging technique, and its potential cytotoxicity was also examined by flow cytometry. The results indicate that C60(C(COOH)2)2 can easily enter cells, and is mainly located in cytoplasm by fluorescein labeling. Furthermore, C60(C(COOH)2)2 can carry the molecule that cannot cross cellular membranes into cells, because fluorescein compound itself cannot enter the cell or adhere to membrane. At concentrations ranging from 1×10?2 to 1×102 mg/L, C60(C(COOH)2)2 does not show any detectable cytotoxicity.

  7. Laser Induced C60 Cage Opening Studied by Semiclassical Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    Yusheng Dou


    Full Text Available Laser induced opening of the C60 cage is studied by a semiclassical electron-radiation-ion dynamics technique. The simulation results indicate that the C60 cage is abruptly opened immediately after laser excitation. The opening of the C60 cage induces a quick increase in kinetic energy and a sharp decrease in electronic energy, suggesting that the breaking of the C60 cage efficiently heats up the cluster and enhances the thermal fragmentation of C60 fullerene.

  8. Solubility of C60 and PCBM in Organic Solvents. (United States)

    Wang, Chun I; Hua, Chi C


    The ability to correlate fullerene solubility with experimentally or computationally accessible parameters can significantly facilitate nanotechnology nowadays for a wide range of applications, while providing crucial insight into optimum design of future fullerene species. To date, there has been no single relationship that satisfactorily describes the existing data clearly manifesting the effects of solvent species, system temperature, and isomer. Using atomistic molecular dynamics simulations on two standard fullerene species, C60 and PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), in a representative series of organic solvent media (i.e., chloroform, toluene, chlorobenzene, 1,3-dichlorobenzene, and 1,2-dichlorobenzene), we show that a single time constant characterizing the dynamic stability of a tiny (angstrom-sized) solvation shell encompassing the fullerene particle can be utilized to effectively capture the known trends of fullerene solubility as reported in the literature. The underlying physics differs substantially between the two fullerene species, however. Although C60 was previously shown to be dictated by a diffusion-limited aggregation mechanism, the side-chain-substituted PCBM is demonstrated herein to proceed with an analogous reaction-limited aggregation with the "reaction rate" set by the fullerene rotational diffusivity in the medium. The present results suggest that dynamic quantities-in contrast to the more often employed, static ones-may provide an excellent means to characterize the complex (entropic and enthalpic) interplay between fullerene species and the solvent medium, shed light on the factors determining the solvent quality of a nanoparticle solution, and, in particular, offer a practical pathway to foreseeing optimum fullerene design and fullerene-solvent interactions.

  9. Graphene oxide-fullerene C60 (GO-C60) hybrid for photodynamic and photothermal therapy triggered by near-infrared light. (United States)

    Li, Qian; Hong, Liang; Li, Hongguang; Liu, Chenguang


    Photodynamic therapy (PDT) and photothermal therapy (PTT) are two promising methodologies for cancer therapy. Although a variety of materials which can be used in PDT and PTT have been developed in the past decades, those showing the combined effect of PDT and PTT under NIR irradiation are rare. Graphene oxide (GO) and fullerene C60 (denoted as C60 hereafter) with unique physical and chemical properties are promising candidates for PTT and PDT, respectively. Here, by using a stepwise conjugation method, a new GO-C60 hybrid which contains hydrophilic methoxypolyethylene glycol (mPEG) and mono-substituted C60 was constructed for combined PDT and PTT. The hybrid shows good solubility in different environments including physiological solutions. The introduction of C60 to GO did not decrease the photothermal properties of GO, while the conjugation of GO to C60 activated the ability of C60 to generate singlet oxygen ((1)O2) in near infrared (NIR) region in aqueous solution. The GO-C60 hybrid also shows good ability to induce the generation of reactive oxygen species (ROS) in Hela cells. Due to the synergistic effect between GO and C60, GO-C60 hybrid exhibits superior performance in the inhibition of cancer cells compared to both individuals, indicating its high potential in practical applications.

  10. Understanding the electronic structure of CdSe quantum dot-fullerene (C60) hybrid nanostructure for photovoltaic applications (United States)

    Sarkar, Sunandan; Rajbanshi, Biplab; Sarkar, Pranab


    By using the density-functional tight binding method, we studied the electronic structure of CdSe quantum dot(QD)-buckminsterfullerene (C60) hybrid systems as a function of both the size of the QD and concentration of the fullerene molecule. Our calculation reveals that the lowest unoccupied molecular orbital energy level of the hybrid CdSeQD-C60 systems lies on the fullerene moiety, whereas the highest occupied molecular orbital (HOMO) energy level lies either on the QD or the fullerene depending on size of the CdSe QD. We explored the possibility of engineering the energy level alignment by varying the size of the CdSe QD. With increase in size of the QD, the HOMO level is shifted upward and crosses the HOMO level of the C60-thiol molecule resulting transition from the type-I to type-II band energy alignment. The density of states and charge density plot support these types of band gap engineering of the CdSe-C60 hybrid systems. This type II band alignment indicates the possibility of application of this nanohybrid for photovoltaic purpose.

  11. C60 superstructure and carbide formation on the Al-terminated Al9Co2(001 ) surface (United States)

    Ledieu, J.; Gaudry, É.; de Weerd, M.-C.; Gille, P.; Diehl, R. D.; Fournée, V.


    We report the formation of an ordered C60 monolayer on the Al9Co2 (001) surface using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), x-ray and ultraviolet photoelectron spectroscopy (XPS/UPS), and ab initio calculations. Dosing fullerenes at 300 K results in a disordered overlayer. However, the adsorption of C60 with the sample held between 573-673 K leads to a [4, -2 ∣1 ,3 ] phase. The growth of C60 proceeds with the formation of two domains which are mirror symmetric with respect to the [100] direction. Within each domain, the superstructure unit cell contains six molecules and this implies an area per fullerene equal to 91 Å2. The molecules exhibit two types of contrast (bright and dim) which are bias dependent. The adsorption energies and preferred molecular configuration at several possible adsorption sites have been determined theoretically. These calculations lead to a possible scheme describing the configuration of each C60 in the observed superstructure. Several defects (vacancies, protrusions,…) and domain boundaries observed in the film are also discussed. If the sample temperature is higher than 693 K when dosing, impinging C60 molecules dissociate at the surface, hence leading to the formation of a carbide film as observed by STM and LEED measurements. The formation of Al4C3 domains and the molecular dissociation are confirmed by XPS/UPS measurements acquired at different stages of the experiment. The cluster substructure present at the Al9Co2 (001) surface dictates the carbide domain orientations.

  12. Variation of Excited-State Dynamics in Trifluoromethyl Functionalized C60 Fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jaehong; Ramirez, Jessica J.; Clikeman, Tyler T.; Larson, Bryon W.; Boltalina, Olga V.; Strauss, Steven H.; Rumbles, Garry


    We report on electronically excited-state dynamics of three different trifluoromethyl C60 fullerenes (TMFs, C60(CF3)n: C60/4-1, C60/6-2, and C60/10-1, featuring four, six, and ten trifluoromethyl groups, respectively) using steady-state and time-resolved optical spectroscopy as well as ultrafast pump/probe transient absorption spectroscopy. C60/4-1 and C60/6-2 dissolved in toluene solvent show near-unity S1--T1 intersystem crossing quantum yield (..phi..ISC), ca. 1 ns S1-state lifetimes, and microsecond-timescale T1-state lifetimes, which are typical of the fullerene class. On the other hand, C60/10-1 exhibits a dominant sub-nanosecond nonradiative S1--S0 relaxation mechanism and negligible ..phi..ISC, therefore decreasing the average excited-state lifetime (..tau..avg) by about 5 orders of magnitude compared to that of C60/4-1 and C60/6-2 (..tau..avg approx. 17 us and 54 us for C60/4-1 and C60/6-2, respectively, whereas ..tau..avg approx. 100 ps for C60/10-1). These excited-state characteristics of C60/4-1 and C60/6-2 are preserved in polymer matrix, suggesting that fullerene/polymer interactions do not modulate intrinsic photophysics of trifluoromethyl-substituted fullerenes. The contrasting excited- state study results of C60/4-1 and C60/6-2 to that of C60/10-1 infer that intrinsic optical properties and excited-state dynamics can be affected by the substitution on the fullerene.

  13. Absorption spectra of C60 and C70 thin films

    Institute of Scientific and Technical Information of China (English)

    周维亚; 解思深; 钱生法; 周棠; 赵日安; 王刚; 钱露茜; 李文治


    The spectra of Cm and Cm thin films over a wide energy range (0.6 to 6.5eV) are measured by transmission spectroscopy and photothermal deflection spectroscopy (PDS), and the optical absorption coefficients are obtained. The optical transitions for the Cm and Cw thin films are analyzed according to the molecular orbital model. The weak absorption spectra of the fullerenes are similar to that of amorphous silicon. The optical energy gaps are given by Tauc’s plots as 1.75 and 1.65eV for C60 and C70 thin films, respectively. The disorders in the fullerene films, which resulted in band-tail state or defect state, are indicated by Urbach edge and sub-gap absorption. It is the disorder that brought the difficulty in determination of the energy gap for fullerenes. The effects of the deflection medium and substrate on the weak absorption spectra of fullerene films are also discussed.

  14. Heterocyclic and heteroatom derivatives of buckminsterfullerene C-60

    NARCIS (Netherlands)

    BellaviaLund, C; KeshavarzK, M; Gonzalez, R; Hummelen, JC; Hicks, R; Wudl, F


    The synthesis of hydroazafullerene and the dimer of azafullerenyl are presented. The structures of these heterofullerene molecules were characterized with the use of proton and carbon NMR as well as C-H and C-N-15 coupling constants.

  15. Probing confinement resonances by photoionizing Xe inside a C60+ molecular cage (United States)

    Phaneuf, R. A.; Kilcoyne, A. L. D.; Aryal, N. B.; Baral, K. K.; Thomas, C. M.; Esteves-Macaluso, D. A.; Lomsadze, R.; Gorczyca, T. W.; Ballance, C. P.; Manson, S. T.; Hasoglu, M. F.; Hellhund, J.; Schippers, S.; Müller, A.


    Double photoionization accompanied by loss of n C atoms (n = 0 , 2 , 4 , 6) was investigated by merging beams of Xe@C60+ ions and synchrotron radiation and measuring the yields of product ions. The giant 4 d dipole resonance of the caged Xe atom has a prominent signature in the cross section for these product channels, which together account for 6 . 2 +/- 1 . 4 of the total Xe 4 d oscillator strength of 10. Compared to that for a free Xe atom, the oscillator strength is redistributed in photon energy due to multipath interference of outgoing Xe 4 d photoelectron waves that may be transmitted or reflected by the spherical C60+ molecular cage, yielding so-called confinement resonances. The data are compared with an earlier measurement and with theoretical predictions for this single-molecule photoelectron interferometer system. Relativistic R-matrix calculations for the Xe atom in a spherical potential shell representing the fullerene cage show the sensitivity of the interference pattern to the molecular geometry.

  16. Interpretation of anomalous normal state optical conductivity of K3C60 fullerides

    Indian Academy of Sciences (India)

    K K Choudhary


    The observed frequency dependent optical response of alkali–metal-doped fulleride superconductors (c ≈ 19 K) has been theoretically analysed. The calculations of the optical conductivity, (), have been made within the two-component schemes: one is the coherent Drude carriers (electrons) responsible for superconductivity and the other is incoherent motion of carriers from one atom to other atom of C60 molecule to a pairing between Drude carriers. The approach accounts for the anomalies reported (frequency dependence of optical conductivity) in the optical measurements for the normal state. The model has only one free parameter, the relaxation rate. The frequency dependent relaxation rates are expressed in terms of memory functions. The coherent Drude carriers form a sharp peak at zero frequency and a long tail at higher frequencies, i.e. in the infrared region. However, the hopping of carriers from one atom to the other (incoherent motion of doped electrons) yields a peak value in the optical conductivity centred at mid-infrared region. It is found that both the Drude and hopping carriers will contribute to the optical process of conduction in the K3C60 and shows similar results on optical conductivity in the mid-infrared as well as infrared frequency regions as those revealed from experiments.

  17. AM1 Study on Structure and Electronic Properties of the Derivatives of C60-S-TTF

    Institute of Scientific and Technical Information of China (English)

    L(U),Mei-Xiang; XIE,Yan; ZENG,He-Ping


    @@ The chemistry of [60]fullerene has been attracted much attention owing to its special structure and unusual property.In recent years, scientists have produced a number of C60-based molecules as well as many materials. Gu et al.[1] have investigated nonlinear optical properties of the derivatives of [60]fullerene, and gained many significant results. The above efforts make photoinduced intra- or inter-molecular electron transfer become currently highly active areas for fundamental study of materials science.

  18. Contaminant-mobilizing capability of fullerene nanoparticles (nC60): Effect of solvent-exchange process in nC60 formation. (United States)

    Wang, Lilin; Fortner, John D; Hou, Lei; Zhang, Chengdong; Kan, Amy T; Tomson, Mason B; Chen, Wei


    Fullerene nanoparticles (nC(60)) in aqueous environments can significantly enhance the transport of hydrophobic organic contaminants by serving as a contaminant carrier. In the present study, the authors examine the effect of the solvent-exchange process on nC(60) aggregate formation and, subsequently, on nC(60) 's contaminant-mobilizing capability. A series of nC(60) samples were prepared using a modified toluene-water solvent-exchange method through the inclusion of a secondary organic solvent in the phase transfer of molecular C(60) in toluene to nC(60) in water. Two groups of solvents--a water-miscible group and a non-water-miscible group-of varied polarity were selected as secondary solvents. The involvement of a secondary solvent in the phase transfer process had only small effects on the particle size and distribution, ζ potential, and mobility of the nC(60) products but significantly influenced the capability of nC(60) to enhance the transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in a saturated sandy soil column, regardless of whether the secondary solvent was water-miscible or non-water-miscible. The two groups of secondary solvents appear to affect the aggregation properties of nC(60) in water via different mechanisms. In general, nC(60) products made with a secondary water-miscible solvent have stronger capabilities to enhance PCB transport. Taken together, the results indicate that according to formation conditions and solvent constituents, nC(60) will vary significantly in its interactions with organic contaminants, specifically as related to adsorption or desorption as well as transport in porous media.

  19. Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ogletree, D.F.


    LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2..sqrt..3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (..sqrt..3 x ..sqrt..3) reconstruction on the (111) face of the ..cap alpha..-CuAl alloy has been determined.

  20. N-Unsubstituted and N-Arylated Fulleropyrrolidines: New Useful Building Blocks for C60 Functionalization

    Institute of Scientific and Technical Information of China (English)

    TONG,Chen-Hua; WU,Zong-Quan; HOU,Jun-Li; LI,Zhan-Ting


    Two series of stable and soluble fulleropyrrolidines have been prepared from the reactions of C60, glycine or its N-arylated derivatives and aliphatic aldehydes or ketones in refluxing toluene or chlorobenzene. The new C60 derivatives represent new useful building blocks for further preparation of more funcionalized C60 derivatives.

  1. Lipid-assisted formation and dispersion of aqueous and bilayer-embedded nano-C60. (United States)

    Chen, Yanjing; Bothun, Geoffrey D


    Lipid assemblies provide a biocompatible approach for preparing aqueous nanoparticles. In this work, dipalmitoylphosphatidylcholine (DPPC) was used to assist in the formation and dispersion of C(60) and nano-C(60) aggregates using a modified reverse phase evaporation (REV) method. This method led to the rapid formation of aqueous nano-C(60) at DPPC/C(60) molar ratios from 500:1 to 100:1 (12-38 nm; verified by cryogenic transmission electron microscopy), which were present in the bulk phase and encapsulated within vesicles. In addition to forming nanoparticles, C(60) was trapped within the vesicle bilayer and led to a reduction in the lipid melting temperature. Solvent extraction was used to isolate nano-C(60) from the lipids and bilayer-embedded C(60). Our results suggest that bilayer-embedded C(60) was present as molecular C(60) and as small amorphous nano-C(60) (2.3 +/- 0.4 nm), which clustered in the aqueous phase after the lipids were extracted. In addition to developing a new technique for nano-C(60) formation, our results suggest that the lipid bilayer may be used as a hydrophobic region for dispersing and assembling small nano-C(60).

  2. Photoinduced Electron Transfer (PET) between C60 and Amines in Micelle Solution - A Kinetic ESR Study

    Institute of Scientific and Technical Information of China (English)


    As indicated by kinetic ESR measurements, the key factor to affect electron recombination in the process of PET between C60 and amines is the space between donor and C60. To increase solubility of C60 in water, it was incorporated into micelle of surfactants.

  3. Ab initio calculation of X-ray emission and IR spectra of the hydrofullerene C 60H 36 (United States)

    Bulusheva, L. G.; Okotrub, A. V.; Antich, A. V.; Lobach, A. S.


    Two isomers of the hydrofullerene C 60H 36 with T and D3 d symmetry were calculated using ab initio Hartree-Fock self-consistent field (HF-SCF). The T symmetry isomer in which the benzenoid rings occupy tetrahedral positions is predicted to be lower in energy than the other considered isomer. Simulated CK α spectra of the isomers were compared with the X-ray fluorescence spectrum of the hydrofullerene C 60H 36 prepared by the transfer hydrogenation method. The short-wave maximum intensity of the CK α spectrum of C 60H 36 was shown to be sensitive to the number of π electrons in the high-occupied levels of the molecule. Although the theoretical spectra are similar in appearance, the T isomer seems to be in better accordance with the experiment. Furthermore, the computed infrared frequencies and intensities for this isomer were found to correlate well with features in the measured spectrum of C 60H 36. The most intense peak in the low-frequency spectral region was shown to correspond to the skeletal vibrations of the benzenoid rings.

  4. Encapsulation of C60 fullerenes into single-walled carbon nanotubes: Fundamental mechanical principles and conventional applied mathematical modeling (United States)

    Baowan, Duangkamon; Thamwattana, Ngamta; Hill, James M.


    A well-known self-assembled hybrid carbon nanostructure is a nanopeapod which may be regarded as the prototype nanocarrier for drug delivery. While the investigation of the packing of C60 molecules inside a carbon nanotube is usually achieved through either experimentation or large scale computation, this paper adopts elementary mechanical principles and classical applied mathematical modeling techniques to formulate explicit analytical criteria and ideal model behavior for such encapsulation. In particular, we employ the Lennard-Jones potential and the continuum approximation to determine three encapsulation mechanisms for a C60 fullerene entering a tube: (i) through the tube open end (head-on), (ii) around the edge of the tube open end, and (iii) through a defect opening on the tube wall. These three encapsulation mechanisms are undertaken for each of the three specific carbon nanotubes (10,10), (16,16), and (20,20). We assume that all configurations are in vacuum and the C60 fullerene is initially at rest. Double integrals are performed to determine the energy of the system and analytical expressions are obtained in terms of hypergeometric functions. Our results suggest that the C60 fullerene is most likely to be encapsulated by head-on through the open tube end and that encapsulation around the tube edge is least likely to occur because of the large van der Waals energy barriers which exist at the tube ends.

  5. Momentum resolved electron stimulated desorption ion angular distribution, a new technique, probing the low frequency motion of adsorbed molecules on single crystal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ahner, J. [Surface Science Center, Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Mocuta, D. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Yates, J.T. Jr. [Surface Science Center, Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)


    A new technique, momentum resolved electron stimulated desorption ion angular distribution (ESDIAD), provides a method for taking snapshots of the zero-point position and lateral momentum of particles adsorbed on crystalline surfaces. By employing state-of-the-art electronics and computer technology it is possible to record for each desorbing particle the desorption direction together with the flight time. High momentum and directional resolved images are obtained, with time-of-flight resolution in the picosecond range and data acquisition rates up to 100 kHz. This enables us to deconvolute spatial and momentum contributions to the ESDIAD pattern and to map the low frequency motion of the adsorbed particles. These maps reflect the adsorbate interactions with the substrate and with neighboring species on the substrate. For selected examples it is demonstrated that by measuring the three dimensional momentum vector for each desorbing particle it is possible to probe the lowest energy states of adsorbed species, as well as to measure the momentum distribution when the adsorbed species gains thermal energy. Such information can be used as a basis for thinking about anisotropies in lateral motion of particles on surfaces. One major opportunity involves the study of dissimilar chemisorbed species which, when imaged together in momentum and real space, give new insights into the first stages of interaction between the species, leading ultimately to a chemical reaction. {copyright} {ital 1999 American Vacuum Society.}

  6. C60-Fullerenes: detection of intracellular photoluminescence and lack of cytotoxic effects

    Directory of Open Access Journals (Sweden)

    Carroll David L


    Full Text Available Abstract We have developed a new method of application of C60 to cultured cells that does not require water-solubilization techniques. Normal and malignant cells take-up C60 and the inherent photoluminescence of C60 is detected within multiple cell lines. Treatment of cells with up to 200 μg/ml (200 ppm of C60 does not alter morphology, cytoskeletal organization, cell cycle dynamics nor does it inhibit cell proliferation. Our work shows that pristine C60 is non-toxic to the cells, and suggests that fullerene-based nanocarriers may be used for biomedical applications.

  7. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Takatsugu Wakahara


    Full Text Available Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV and poly(3-hexylthiophene (P3HT, with C60 nanowhiskers (C60NWs were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer composite films, resulting in a power conversion efficiency of ~0.01% for P3HT with short length thin C60NWs, which is higher than that previously reported for thick C60 nanorods. The present study gives new guidance on the selection of the type of C60NWs and the appropriate polymer for new photovoltaic devices.

  8. Effects of exchange-correlation potentials on the density-functional description of C60 versus C240 photoionization (United States)

    Choi, Jinwoo; Chang, EonHo; Anstine, Dylan M.; Madjet, Mohamed El-Amine; Chakraborty, Himadri S.


    We study the photoionization properties of the C60 versus C240 molecule in a spherical jellium frame of the density-functional method. Two prototypical approximations of the exchange-correlation (xc) functional are used: (i) the Gunnarsson-Lundqvist parametrization [Gunnarsson and Lundqvist, Phys. Rev. B 13, 4274 (1976), 10.1103/PhysRevB.13.4274] with a correction for the electron self-interaction (SIC) introduced artificially from the outset and (ii) a gradient-dependent augmentation of approximation (i) using the van Leeuwen and Baerends model potential [van Leeuwen and Baerends, Phys. Rev. A 49, 2421 (1994), 10.1103/PhysRevA.49.2421], in lieu of SIC, that restores electrons' asymptotic properties intrinsically within the formalism. Ground-state results from the two schemes for both molecules show differences in the shapes of mean-field potentials and bound-level properties. The choice of an xc scheme also significantly alters the dipole single-photoionization cross sections obtained by an ab initio method that incorporates linear-response dynamical correlations. Differences in the structures and ionization responses between C60 and C240 uncover the effect of molecular size on the underlying physics. Analysis indicates that the collective plasmon resonances with the gradient-based xc option produce results noticeably closer to the experimental data available for C60.

  9. Hierarchical aqueous self-assembly of C60 nano-whiskers and C60-silver nano-hybrids under continuous flow. (United States)

    Iyer, K Swaminathan; Raston, Colin L; Saunders, Martin


    The ubiquitous starch-iodine complex can be used to organize hydrophobic fullerene C(60) in water into nano-whiskers shrouded by the biopolymer, and are approximately 5-8 nm in cross section, and 250-350 nm in length, as a hierarchical self assembly process. The preformed starch-iodine complex reacts with solid pristine C(60) affording nano-whiskers with iodine surrounding the fullerene array, the iodine then being removed on treatment with ascorbic acid. The hydrophobic surface of the nano-whiskers of C(60) can be coated with silver metal in a controlled way using 'soft energy' spinning disc processing.

  10. Photochemical properties of C 60. Triplet-excited C 60 quenching by electron acceptors TCNQ and TCNE in solution. Laser photolysis study (United States)

    Nadtochenko, Victor A.; Denisov, Nikolai N.; Rubtsov, Igor V.; Lobach, Anatolii S.; Moravskii, Alexander P.


    The quenching of triplet-excited 3C 60 by electron acceptors TCNQ and TCNE has been established in nonpolar toluene and moderately polar benzonitrile solutions. The quenching constants kq are 5.5 × 10 9 in toluene, 2.2 × 10 9 in benzonitrile for TCNQ and 7.9 × 10 5 in toluene, 4.2 × 10 8 (M s) -1 in benzonitrile for TCNE. The 3C 60 quenching can be explained by triplet exciplex formation. The time-resolved spectra of the C 60/TCNE system exhibit a well pronounced charge-transfer excited state [C δ60 … TCNE δ-] in benzonitrile.

  11. Composition dependence of magnetic and magnetotransport properties in C60-Co granular thin films (United States)

    Sugai, Isamu; Sakai, Seiji; Matsumoto, Yoshihiro; Naramoto, Hiroshi; Mitani, Seiji; Takanashi, Koki; Maeda, Yoshihito


    Composition dependence of magnetic and magnetotransport properties in C60Cox thin films exhibiting large magnetoresistance (MR) effect was investigated in the Co composition range of x =8-20, where x denotes the number of Co atoms per C60 molecule. From the superparamagnetic magnetization curves observed, the average diameter (dave) of Co nanoparticles dispersed in the matrix phase was evaluated to be approximately 1 nm for the sample of x =8, and increased with the Co composition, x. By analyzing the temperature (T) dependence of resistivity based on the model by Abeles et al. [Adv. Phys. 24, 407 (1975)], the average charging energies (⟨ÊC⟩) of Co nanoparticles were evaluated to be 2-9 meV for the samples of x =8-17 while the considerably weak temperature dependence suggested much smaller values of ⟨ÊC⟩ for the samples of x >17. The composition dependence of dave and ⟨ÊC⟩ revealed a structural transition from well-defined granular structures in the range of x =8-17 to magnetically and electronically coupled states of Co nanoparticles over x ˜17. As a result of the structural change, the MR behavior became different between the two composition regions separated at x ˜17. In particular, for the samples of x =8-17, the bias-voltage (V) dependence of the MR ratio in the low-V region fits well with an unusual exponential form of MR=MR0 exp(-V/Vc) at T proportion to ⟨ÊC⟩ and also that the fitting parameter Vc is closely correlated with ⟨ÊC⟩. These results indicate that the charging effect of Co nanoparticles plays an important role in the anomalously large MR effect of C60-Co granular films. In addition, the power-law dependence of MR on T (MR∝T-α,α˜2) was also observed at relatively high temperature range T ≥10 K in the wide range of the composition.

  12. A comparative electrochemical study of electrosorbed 2- and 4-mercaptopyridines and their application as corrosion inhibitors at C60 steel

    Indian Academy of Sciences (India)

    Nazly Hassan; Rudolf Holze


    The electrochemistry of self-assembled monolayers (SAMs) prepared from 2-mercaptopyridine (2 Mpy) and 4-mercaptopyridine (4 Mpy) dissolved in either water or an aqueous solution of 0.1 M H2SO4 on a polycrystalline gold electrode has been investigated in an aqueous electrolyte solution (0.5 M H2SO4) using cyclic voltammetry. Results suggest that 2 Mpy is adsorbed more strongly than 4 Mpy due to the formation of a S-Au-N chelate. The under- and over-potential deposition of copper from an aqueous solution of 0.1 M sulphuric acid is inhibited in the presence of these SAMs suggesting strong interactions between these adsorbates and the gold surface. A copper adlayer was partially displaced by adsorbing 2 Mpy and 4 Mpy. The inhibition effect of these SAMs on the corrosion of C60 steel has been investigated using electrochemical impedance measurements (EIM) in an aqueous 3.5 wt% NaCl solution. The polarization resistance and the inhibition efficiency were calculated. 2 Mpy has higher inhibition efficiency than 4 Mpy.

  13. Phenothiazine-bridged cyclic porphyrin dimers as high-affinity hosts for fullerenes and linear array of C60 in self-assembled porphyrin nanotube. (United States)

    Sakaguchi, Ken-ichi; Kamimura, Takuya; Uno, Hidemitsu; Mori, Shigeki; Ozako, Shuwa; Nobukuni, Hirofumi; Ishida, Masatoshi; Tani, Fumito


    Free-bases and a nickel(II) complex of phenothiazine-bridged cyclic porphyrin dimers bearing self-assembling 4-pyridyl groups (M2-Ptz-CPDPy(OCn); M = H2 or Ni, OCn = OC6 or OC3) at opposite meso-positions have been prepared as host molecules for fullerenes. The free-base dimer (H4-Ptz-CPDPy(OC6)) includes fullerenes with remarkably high association constants such as 3.9 ± 0.7 × 10(6) M(-1) for C60 and 7.4 ± 0.8 × 10(7) M(-1) for C70 in toluene. This C60 affinity is the highest value ever among reported receptors composed of free-base porphyrins. The nickel dimer (Ni2-Ptz-CPDPy(OC6)) also shows high affinities for C60 (1.3 ± 0.2 × 10(6) M(-1)) and C70 (over 10(7) M(-1)). In the crystal structure of the inclusion complex of C60 within H4-Ptz-CPDpy(OC3), the C60 molecule is located just above the centers of the porphyrins. The two porphyrin planes are almost parallel to each other and the center-to-center distance (12.454 Å) is close to the optimal separation (∼12.5 Å) for C60 inclusion. The cyclic porphyrin dimer forms a nanotube through its self-assembly induced by C-H···N hydrogen bonds between porphyrin β-CH groups and pyridyl nitrogens as well as π-π interactions of the pyridyl groups. The C60 molecules are linearly arranged in the inner channel of this nanotube.

  14. Dynamic solvation shell and solubility of C60 in organic solvents. (United States)

    Wang, Chun I; Hua, Chi C; Chen, Show A


    The notion of (static) solvation shells has recently proved fruitful in revealing key molecular factors that dictate the solubility and aggregation properties of fullerene species in polar or ionic solvent media. Using molecular dynamics schemes with carefully evaluated force fields, we have scrutinized both the static and the dynamic features of the solvation shells of single C60 particle for three nonpolar organic solvents (i.e., chloroform, toluene, and chlorobenzene) and a range of system temperatures (i.e., T = 250-330 K). The central findings have been that, while the static structures of the solvation shell remain, in general, insensitive to the effects of changing solvent type or system temperature, the dynamic behavior of solvent molecules within the shell exhibits prominent dependence on both factors. Detailed analyses led us to propose the notion of dynamically stable solvation shell, effectiveness of which can be characterized by a new physical parameter defined as the ratio of two fundamental time constants representing, respectively, the solvent relaxation (or residence) time within the first solvation shell and the characteristic time required for the fullerene particle to diffuse a distance comparable to the shell thickness. We show that, for the five (two from the literature) different solvent media and the range of system temperatures examined herein, this parameter bears a value around unity and, in particular, correlates intimately with known trends of solubility for C60 solutions. We also provide evidence revealing that, in addition to fullerene-solvent interactions, solvent-solvent interactions play an important role, too, in shaping the dynamic solvation shell, as implied by recent experimental trends.

  15. The spin chemistry and magnetic resonance of H2@C60. From the Pauli principle to trapping a long lived nuclear excited spin state inside a buckyball. (United States)

    Turro, Nicholas J; Chen, Judy Y-C; Sartori, Elena; Ruzzi, Marco; Marti, Angel; Lawler, Ronald; Jockusch, Steffen; López-Gejo, Juan; Komatsu, Koichi; Murata, Yasujiro


    One of the early triumphs of quantum mechanics was Heisenberg's prediction, based on the Pauli principle and wave function symmetry arguments, that the simplest molecule, H(2), should exist as two distinct species-allotropes of elemental hydrogen. One allotrope, termed para-H(2) (pH(2)), was predicted to be a lower energy species that could be visualized as rotating like a sphere and possessing antiparallel ( upward arrow downward arrow) nuclear spins; the other allotrope, termed ortho-H(2) (oH(2)), was predicted to be a higher energy state that could be visualized as rotating like a cartwheel and possessing parallel ( upward arrow upward arrow) nuclear spins. This remarkable prediction was confirmed by the early 1930s, and pH(2) and oH(2) were not only separated and characterized but were also found to be stable almost indefinitely in the absence of paramagnetic "spin catalysts", such as molecular oxygen, or traces of paramagnetic impurities, such as metal ions. The two allotropes of elemental hydrogen, pH(2) and oH(2), may be quantitatively incarcerated in C(60) to form endofullerene guest@host complexes, symbolized as pH(2)@C(60) and oH(2)@C(60), respectively. How does the subtle difference in nuclear spin manifest itself when hydrogen allotropes are incarcerated in a buckyball? Can the incarcerated "guests" communicate with the outside world and vice versa? Can a paramagnetic spin catalyst in the outside world cause the interconversion of the allotropes and thereby effect a chemical transformation inside a buckyball? How close are the measurable properties of H(2)@C(60) to those computed for the "quantum particle in a spherical box"? Are there any potential practical applications of this fascinating marriage of the simplest molecule, H(2), with one of the most beautiful of all molecules, C(60)? How can one address such questions theoretically and experimentally? A goal of our studies is to produce an understanding of how the H(2) guest molecules incarcerated in

  16. Formation of a new adduct based on fullerene tris-malonate samarium salt C60-[C60(=C(COO)2)3]Sm2 (United States)

    Petrov, A. A.; Keskinov, V. A.; Semenov, K. N.; Charykov, N. A.; Letenko, D. G.; Nikitin, V. A.


    Gram quantities of a new adduct based on light fullerene tris-malonate samarium salt C60 [C60(=C(COO)2)3]Sm2 are obtained via the reaction of ion exchange. The obtained adduct is studied by means of electron and infrared spectroscopy, X-ray and elemental analysis, electron microscopy, and thermogravimetry. The polythermal solubility of [C60(=C(COO)2)3]Sm2 in water is determined in ampoules via saturation within 20-70°C. The composition of crystalline hydrate [C60(=C(COO)2)3]Sm2 · 36H2O, which exists in equilibrium with the saturated solution, is estimated.

  17. Preparation and Study of Hollow Nanoshells%C_(60)空心纳米壳的制备及研究

    Institute of Scientific and Technical Information of China (English)

    刘珵; 董威红; 刘淼; 张洋; 范楼珍


    C_(60) hollow nanoshells were firstly prepared in a binary organic solution of m-xylene and ace-tonitrile by applying ultrasonication.The morphologies of C_(60) hollow nanoshells were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).The-outer diameter and inner diameter were 300~400 nm and 200~300 nm respectively,and the thickness of the wall was about 100 nm.The image of TEM certified that the sample took a hollow structure.XRD and FTIR spectrum results showed that the C_(60) hollow nanoshells were of a single crystalline structure and composed of pristine C_(60) molecules.The uniform C_(60) hollow nanoshell electrode was prepared by electrophoresis and the Au nanoparticles were then deposited by an electrochemical reduction method.The following depositions of other metals are continuing.The applications of these metal/C_(60) hollow nanoshell electrodes to the biosensors and fuel cells are being studied.%利用超声技术,选择间二甲苯溶液和乙腈两种不互溶的溶剂,首次成功地制备了C_(60)的空心纳米壳.选择扫描电镜(SEM),透射电镜(TEM)等对所制得的C_(60)的空心纳米壳的形貌及结构进行表征.C_(60)空心纳米壳的外直径为300~400nm,内直径为200~300 nm,壁厚约100 nm.X射线衍射光谱(XRD)、傅里叶红外光谱检测结果表明其为C_(60)分子组成的单晶结构.利用电泳方法制备了均匀的C_(60)的空心纳米壳膜电极,并利用电沉积方法在所制备的C_(60)的空心纳米壳电极表面沉积了金(Au)纳米颗粒.为进一步沉积其它金属,研究其在生物传感器及燃料电池方面的应用提供了基础.

  18. Distribution and Biomarker of Carbon-14 Labeled Fullerene C60 ([14C(U)]C60) in Pregnant and Lactating Rats and their Offspring after Maternal Intravenous Exposure (United States)

    Snyder, Rodney W.; Fennell, Timothy R.; Wingard, Christopher J.; Mortensen, Ninell P.; Holland, Nathan A.; Shannahan, Jonathan H.; Pathmasiri, Wimal; Lewin, Anita H.; Sumner, Susan C. J.


    A comprehensive distribution study was conducted in pregnant and lactating rats exposed to a suspension of uniformly carbon-14 labeled C60 ([14C(U)]C60). Rats were administered [14C(U)]C60 (~0.2 mg [14C(U)]C60/kg body weight) or 5% polyvinylpyrrolidone (PVP)-saline vehicle via a single tail vein injection. Pregnant rats were injected on gestation day (GD) 11 (terminated with fetuses after either 24h or 8d), GD15 (terminated after 24h or 4d), or GD18 (terminated after 24h). Lactating rats were injected on postnatal day 8 and terminated after 24h, 3d or 11d. The distribution of radioactivity in pregnant dams was influenced by both the state of pregnancy and time of termination after exposure. The percentage of recovered radioactivity in pregnant and lactating rats was highest in liver and lungs. Radioactivity was quantitated in over 20 tissues. Radioactivity was found in placenta and in fetuses of pregnant dams, and in the milk of lactating rats and in pups. Elimination of radioactivity was <2% in urine and feces at each time point. Radioactivity remained in blood circulation up to 11 days after [14C(U)]C60 exposure. Biomarkers of inflammation, cardiovascular injury and oxidative stress were measured to study the biological impacts of [14C(U)]C60 exposure. Oxidative stress were elevated in female pups of exposed dams. Metabolomics analysis of urine showed that [14C(U)]C60 exposure to pregnant rats impacted the pathways of vitamin B, regulation of lipid and sugar metabolism and aminoacyl-tRNA biosynthesis. This study demonstrated that [14C(U)]C60 crosses the placenta at all stages of pregnancy examined, and is transferred to pups via milk. PMID:26081520

  19. Raman spectroscopy measurements of the vibrational properties of uv-polymerized C60 thin film and C60 powder compressed in a diamond anvil cell (United States)

    Li, Y.; Singh, D.; Sharma, S. C.


    We present results from a series of experiments designed to further study the effects of pressure on the vibrational properties of C60 compressed under high pressures (10 GPa) in a diamond anvil cell. The Raman scattering measurements were made by using a high resolution optical spectrometer that consists of a 1.25 m, f/11 monochromator, 2400 g/mm, ion-etched blazed holographic diffraction grating, 2048x512 pixel back illuminated liquid nitrogen cooled CCD camera, Super-Notch-Plus filter, argon-ion laser operating at 514.5 nm, and SpectraMax for Windows software. The Raman scattering measurements on C60 thin films show a large ( 10 cm-1) and characteristic red shift in the pentagonal pinch mode Ag(2) of pristine C60 upon irradiation by 21.2 eV photons. Upon heating this film under 10(-3) Torr vacuum at 413 and 473 K, the Raman spectra shift towards the pentagonal pinch mode of pristine C60. These results are in agreement with previously published data (1,2) and they show that the film is polymerized because of uv irradiation. We have also measured spectra for C60 powder compressed under high pressures in a diamond anvil cell. We present results for several frequencies of the Raman active modes of C60. 1. A. M. Rao et al, Science 259, 955 (1993); 2. S. C. Sharma et al, Mat. Res. Symp. Proc. 695, L3.10 (2002)


    Institute of Scientific and Technical Information of China (English)

    Hong-yao Xu; Ben-zhong Tang


    While WCl6-Ph4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, high molecular weight (Mw up to 410×103) polymers are obtained in high yields (up to 80%) when the polymerizations of PP are carried out in the presence of C60 using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecular structures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C60 is copolymerized with PP. Thus C60 plays the dual roles of comonomer and cocatalyst in the polymerization reaction. C60 contents of the copolymers can be easily changed by varying the C60 amounts in the feed mixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance is superior to that of parent C60.

  1. Hybridization-Induced Carrier Localization at the C60/ZnO Interface

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Leah L.; Racke, David A.; Kim, Hyungchul; Ndione, Paul; Sigdel, Ajaya K.; Berry, Joseph J.; Graham, Samuel; Nordlund, Dennis; Monti, Oliver L. A.


    Electronic coupling and ground-state charge transfer at the C60/ZnO hybrid interface is shown to localize carriers in the C60 phase. This effect, revealed by resonant X-ray photoemission, arises from interfacial hybridization between C60 and ZnO. Such localization at carrier-selective electrodes and interlayers may lead to severely reduced carrier harvesting efficiencies and increased recombination rates in organic electronic devices.

  2. Molecular modeling of C 60:cobaltocene and nickelocene complexes, comparison with IR absorption (United States)

    Byszewski, P.; Antonova, K.; Kowalska, E.; Radomska, J.; Baran, J.


    C 60 was reacted with cobaltocene and nickelocene. The samples of the composition C 60(Cocp 2) 3 and C 60Nicp 2 were obtained in the reaction. Their thermal stability was measured by Thermogravimetry and Differential Scanning Calorimetry and the vibrational spectrum was investigated by infrared absorption. Hydrocarbon groups may be evacuated from the reaction products by annealing, while metal atoms remain dispersed between fullerenes. The experiments are compared with the molecular modeling results obtained by applying the PM3 model.

  3. Neutron scattering study of Na2C60 in the pressure-temperature plane (United States)

    Yildirim, T.; Neumann, D. A.; Trevino, S. F.; Fischer, J. E.


    Na2C60 is the only known fulleride with divalent C60 and orientational order (Pa3¯ symmetry). We investigated the phase behavior of Na2C60 for 0200 K and P>1 kbar, the structure is transformed into a low-symmetry distorted phase. Here the peaks at low Q are significantly broadened while the high Q peaks are almost completely smeared out. This transformation is reversible; releasing pressure above 200 K recovers the cubic Pa3¯ structure.

  4. Study of the interaction of C60 fullerene with human serum albumin in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Song [Vanderbilt University; Zhao, Xiongce [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health; Mo, Yiming [ORNL; Cummings, Peter T [ORNL; Heller, William T [ORNL


    Concern about the toxicity of engineered nanoparticles, such as the prototypical nanomaterial C60 fullerene, continues to grow. While evidence continues to mount that C60 and its derivatives may pose health hazards, the specific molecular interactions of these particles with biological macromolecules require further investigation. To better understand the interaction of C60 with proteins, the protein human serum albumin (HSA) was studied in solution with C60 at C60:HSA molar ratios ranging from 1:2 to 4:1. HSA is the major protein component of blood plasma and plays a role in a variety of functions, such as the maintenance of blood pH and pressure. The C60-HSA interaction was probed by a combination of circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS) and atomistic molecular dynamics (MD) simulations to understand C60-driven changes in the structure of HSA in solution. The CD spectroscopy demonstrates that the secondary structure of the protein decreases in -helical content in response to the presence of C60. Similarly, C60 produces subtle changes in the solution conformation of HSA, as evidenced by the SANS data and MD. The data do not indicate that C60 is causing a change in the oligomerization state of the protein. Taken together results demonstrate that C60 interacts with HSA, but it does not strongly perturb the structure of the protein by unfolding it or inducing aggregation, suggesting a mechanism for transporting C60 throughout the body to accumulate in various tissues.

  5. C60(Nd) nanoparticles enhance chemotherapeutic susceptibility of cancer cells by modulation of autophagy (United States)

    Wei, Pengfei; Zhang, Li; Lu, Yang; Man, Na; Wen, Longping


    Autophagy, an evolutionally conserved intracellular process degrading cytoplasmic proteins and organelles for recycling, has become one of the most remarkable strategies applied in cancer research. The fullerene C60 nanoparticle (nC60) has been shown to induce autophagy and sensitize chemotherapeutic killing of cancer cells, but the details still remain unknown. Here we show that a water-dispersed nanoparticle solution of derivatized fullerene C60, C60(Nd) nanoparticles (nC60(Nd)), has greater potential in inducing autophagy and sensitizing chemotherapeutic killing of both normal and drug-resistant cancer cells than nC60 does in an autophagy-dependent fashion. Additionally we further demonstrated that autophagy induced by nC60/C60(Nd) and Rapamycin had completely different roles in cancer chemotherapy. Our results, for the first time, revealed a novel and more potent derivative of the C60 nanoparticle in enhancing the cytotoxicity of chemotherapeutic agents and reducing drug resistance through autophagy modulation, which may ultimately lead to novel therapeutic strategies in cancer therapy.

  6. C60(Nd) nanoparticles enhance chemotherapeutic susceptibility of cancer cells by modulation of autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Wei Pengfei; Zhang Li; Man Na; Wen Longping [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui (China); Lu Yang, E-mail: [Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui (China)


    Autophagy, an evolutionally conserved intracellular process degrading cytoplasmic proteins and organelles for recycling, has become one of the most remarkable strategies applied in cancer research. The fullerene C60 nanoparticle (nC60) has been shown to induce autophagy and sensitize chemotherapeutic killing of cancer cells, but the details still remain unknown. Here we show that a water-dispersed nanoparticle solution of derivatized fullerene C60, C60(Nd) nanoparticles (nC60(Nd)), has greater potential in inducing autophagy and sensitizing chemotherapeutic killing of both normal and drug-resistant cancer cells than nC60 does in an autophagy-dependent fashion. Additionally we further demonstrated that autophagy induced by nC60/C60(Nd) and Rapamycin had completely different roles in cancer chemotherapy. Our results, for the first time, revealed a novel and more potent derivative of the C60 nanoparticle in enhancing the cytotoxicity of chemotherapeutic agents and reducing drug resistance through autophagy modulation, which may ultimately lead to novel therapeutic strategies in cancer therapy.

  7. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application


    Takatsugu Wakahara; Kun’ichi Miyazawa; Osamu Ito; Nobutaka Tanigaki


    Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), with C60 nanowhiskers (C60NWs) were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer) composite films, result...

  8. Molecular solubilization of fullerene C60 in water by γ-cyclodextrin thioethers

    Directory of Open Access Journals (Sweden)

    Hai Ming Wang


    Full Text Available Various hydrophilic γ-cyclodextrin (CD thioethers, containing neutral or ionic side arms were found to form molecular disperse solutions of C60 in water reaching concentrations of 15 mg/L. Equilibrium state was approached after seven days without the use of organic cosolvents. The 1:2 stoichiometry of the C60/γ-CD thioether complexes was demonstrated by a parabolic phase-solubility diagram. In contrast, native γ-CD forms nanoparticles with C60. Particle sizes of C60 were determined by dynamic light scattering.

  9. Synthesis and optical limiting in copolymers of C60 and 1-phenyl-1-butyne

    Institute of Scientific and Technical Information of China (English)


    While WCl6-Ph4Sn is a poor catalyst for the polymerization of 1-phenyl-butyne (PB) at room temperature, it effectively polymerizes PB in the presence of C60, giving high molecular weight polymers in high yields.The polymer is soluble in THF and chloroform and spectroscopic analysis reveals that C60 has copolymerized with PB.Thus, C60 plays dual roles of comonomer and cocatalyst in the acetylene polymerization.The copolymers strongly attenuate 532-nm laser pulses, whose limiting performance is superior to that of parent C60.

  10. Solvent-free functionalization of fullerene C60 and pristine multi-walled carbon nanotubes with aromatic amines (United States)

    Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Gromovoy, Taras Yu.; Chávez-Uribe, Ma. Isabel; Basiuk, Vladimir A.; Basiuk, Elena V.


    We employed a direct one-step solvent-free covalent functionalization of solid fullerene C60 and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180-250 °C, during relatively short time of about 2 h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, 13C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C60 molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C60, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.

  11. Modeling of the Transport and Retention of Fullerene C60 Aggregates in Porous Media (United States)

    Li, Y.; Wang, Y.; Pennell, K.; Abriola, L.


    Buckminster fullerene (C60) has recently gained wide application in many commercial products. Given its widespread use, release of C60 into the environment during manufacture, transportation, and/or application is likely. Although C60 has negligible solubility in water, it is capable of acquiring charge and form highly stable nano-scale aggregates (nC60) in aqueous systems. In recent years, several laboratory research efforts have been devoted to studying the potential fate and transport of nC60 in porous media representative of the natural subsurface environment. Traditional clean-bed filtration theory is typically applied to analyze the experimental results. Far less attention has focused on the applicability of filtration theory to nC60 transport under different soil and solution conditions. In this work, we simulate column transport of nC60 under progressively more complex conditions and compare with laboratory observations. For nC60 transport in columns packed with Ottawa sand and simple electrolyte solutions, i.e. 1mM CaCl2 and 1mM NaCl, simulation results reveal that traditional clean-bed filtration theory is not sufficient to model the asymmetric breakthrough curves and relatively flat retention profiles observed in these systems. Modification of the filtration model, incorporating a maximum retention capacity term, can provide remarkably improved modeling results. The second application is for transport of nC60 in Ottawa sand coated with surfactant. The observed retention profiles in these experiments exhibit a hyper-exponential feature. Modeling results demonstrate that coupled simulation of both surfactant and nC60 transport is required to correctly capture the hyper-exponential retention profile in these systems. Finally, efforts to model the transport of nC60 in real soils, including Appling and Webster soils, are presented, suggesting that modification of filtration theory is also necessary in this case, to capture the shape of the observed retention

  12. Transport and retention of fullerene (C60) nanoparticles in natural soils (United States)

    Wang, Y.; Li, Y.; Abriola, L. M.; Pennell, K. D.


    Although several column studies have investigated the transport and deposition of fullerene (C60) nanoparticles in ideal porous media, such as washed quartz sands and glass beads, far less attention has been directed toward natural soils. To address this issue, a series of column experiments was performed to quantify the transport and retention of C60 nanoparticles in a borosilicate glass column (10 cm length x 2.5 cm dia.) packed with either Appling soil or Webster soil. Introduction of a C60 suspension containing 1 mM calcium chloride as background electrolyte for up to 65 pore volumes resulted in 100 percent retention of injected mass. Retained C60 nanoparticles were concentrated within 6 cm of the column from inlet, with solid phase concentrations approaching 130 μg/g. The presence of Suwannee River humic acid (20 mg/L) in the C60 suspension slightly enhanced mobility of nC60, although effluent breakthrough was not observed. However, when mixed with 1,000 mg/L polyethoxylate (20) sorbitan monooleate (Tween 80), C60 nanoparticles were readily transported through Appling soil, with less than 40 percent of injected mass retained. Retentions profiles of nC60 exhibited gradual ascent and descent, but not symmetrically, with distance from inlet. A mathematic transport model incorporating classical filtration theory, non-linear sorption process, and straining was utilized to capture C60 effluent breakthrough curves and retention profiles observed in the column experiments. These findings indicate that Appling soil and Webster soil exhibit large retention capacity for C60 nanoparticle, and that transport of C60 is greatly enhanced in the presence of stabilizing agents.

  13. Fullerene C60 Penetration into Leukemic Cells and Its Photoinduced Cytotoxic Effects (United States)

    Franskevych, D.; Palyvoda, K.; Petukhov, D.; Prylutska, S.; Grynyuk, I.; Schuetze, C.; Drobot, L.; Matyshevska, O.; Ritter, U.


    Fullerene C60 as a representative of carbon nanocompounds is suggested to be promising agent for application in photodynamic therapy due to its unique physicochemical properties. The goal of this study was to estimate the accumulation of fullerene C60 in leukemic cells and to investigate its phototoxic effect on parental and resistant to cisplatin leukemic cells. Stable homogeneous water colloid solution of pristine C60 with average 50-nm diameter of nanoparticles was used in experiments. Fluorescent labeled C60 was synthesized by covalent conjugation of C60 with rhodamine B isothiocyanate. The results of confocal microscopy showed that leukemic Jurkat cells could effectively uptake fullerene C60 from the medium. Light-emitting diode lamp (100 mW cm-2, λ = 420-700 nm) was used for excitation of accumulated C60. A time-dependent decrease of viability was detected when leukemic Jurkat cells were exposed to combined treatment with C60 and visible light. The cytotoxic effect of photoexcited C60 was comparable with that induced by H2O2, as both agents caused 50% decrease of cell viability at 24 h at concentrations about 50 μM. Using immunoblot analysis, protein phosphotyrosine levels in cells were estimated. Combined action of C60 and visible light was followed by decrease of cellular proteins phosphorylation on tyrosine residues though less intensive as compared with that induced by H2O2 or protein tyrosine kinase inhibitor staurosporine. All tested agents reduced phosphorylation of 55, 70, and 90 kDa proteins while total suppression of 26 kDa protein phosphorylation was specific only for photoexcited C60.

  14. Tuning the molecular order of C60-based self-assembled monolayers in field-effect transistors. (United States)

    Schmaltz, Thomas; Khassanov, Artoem; Steinrück, Hans-Georg; Magerl, Andreas; Hirsch, Andreas; Halik, Marcus


    The control of order in organic semiconductor systems is crucial to achieve desired properties in electronic devices. We have studied the order in fullerene functionalized self-assembled monolayers by mixing the active molecules with supporting alkyl phosphonic acids of different chain length. By adjusting the length of the molecules, structural modifications of the alignment of the C60 head groups within the SAM can be tuned in a controlled way. These changes on the sub-nanometre scale were analysed by grazing incidence X-ray diffraction and X-ray reflectivity. To study the electron transport properties across these layers, self-assembled monolayer field-effect transistors (SAMFETs) were fabricated containing only the single fullerene monolayer as semiconductor. Electrical measurements revealed that a high 2D crystalline order is not the only important aspect. If the fullerene head groups are too confined by the supporting alkyl phosphonic acid molecules, defects in the crystalline C60 film, such as grain boundaries, start to strongly limit the charge transport properties. By close interpretation of the results of structural investigations and correlating them to the results of electrical characterization, an optimum chain length of the supporting alkyl phosphonic acids in the range of C10 was determined. With this study we show that minor changes in the order on the sub-nanometre scale, can strongly influence electronic properties of functional self-assembled monolayers.

  15. Fullerene C60 Simulated with a Superconducting Microwave Resonator and Test of the Atiyah-Singer Index Theorem (United States)

    Dietz, B.; Klaus, T.; Miski-Oglu, M.; Richter, A.; Bischoff, M.; von Smekal, L.; Wambach, J.


    We report first experiments with a macroscopic-size superconducting microwave resonator that has the geometric structure of the C60 fullerene molecule. Our high-resolution measurements reveal the exceptional spectral properties that stem from the icosahedral symmetry of its carbon lattice. In particular, they allow us to determine the number of zero-energy modes, i.e., of modes with energy values at the Dirac point existent in the band structure due to the hexagonal arrangements of the carbon atoms, and to test the Atiyah-Singer index theorem which relates this number to the topology of the curved carbon lattice.

  16. Extraterrestrial Helium (He@C60) Trapped in Fullerenes in the Sudbury Impact Structure (United States)

    Becker, L.; Bada, J. L.; Poreda, R. J.; Bunch, T. E.


    Fullerenes (C60 and C70) have recently been identified in a shock-produced breccia (Onaping Formation) associated with the 1.85-Ga Sudbury Impact Crater. The presence of parts-per-million levels of fullerenes in this impact structure raises interesting questions about the processes that led to the formation of fullerenes and the potential for delivery of intact organic material to the Earth by a large bolide (e.g., asteroid or comet). Two possible scenarios for the presence of fullerenes in the Sudbury impact deposits are that (1) fullerenes are synthesized within the impact plume from the C contained in the bolide; or (2) fullerenes are already present in the bolide and survived the impact event. The correlation of C and trapped noble gas atoms in meteorites is well established. Primitive meteorites contain several trapped noble gas components that have anomalous isotopic compositions, some of which may have a presolar origin. Several C-bearing phases, including SiC, graphite, and diamond, have been recognized as carriers of trapped noble gases. It has also been suggested that fullerenes (C60 and C70) might be a carrier of noble gas components in carbonaceous chondrites. Recently, fullerenes have been detected in separate samples in the Allende meteorite. Carbon-60 is large enough to enclose the noble gases He, Ne, Ar, Kr, and Xe, but it is too small to contain diatomic gases such as N2 or triatomic gases such as CO2. Recent experimental work has demonstrated that noble gases of a specific isotopic composition can be introduced into synthetic fullerenes at high temperatures and pressures; these encapsulated gases can then be released by the breaking of one or more C bonds during step-heating under vacuum. These thermal-release patterns for He encapsulated within the C60 molecule (He@C60) are similar to the patterns for acid residues of carbonaceous chondrites, suggesting that fullerenes could be an additional carrier of trapped noble gases in acid residues of

  17. Targeted adsorption of molecules in the colon with the novel adsorbent-based medicinal product, DAV132: A proof of concept study in healthy subjects. (United States)

    de Gunzburg, Jean; Ducher, Annie; Modess, Christiane; Wegner, Danilo; Oswald, Stefan; Dressman, Jennifer; Augustin, Violaine; Feger, Céline; Andremont, Antoine; Weitschies, Werner; Siegmund, Werner


    During antibiotic treatments, active residuals reaching the colon profoundly affect the bacterial flora resulting in the emergence of resistance. To prevent these effects, we developed an enteric-coated formulated activated-charcoal based product, DAV132, meant to deliver its adsorbent to the ileum and neutralize antibiotic residues in the proximal colon. In a randomized, control, crossover study, the plasma pharmacokinetics of the probe drugs amoxicillin (500 mg) absorbed in the proximal intestine, and sulfapyridine (25 mg) metabolized from sulfasalazine in the cecum and rapidly absorbed, were compared after a single administration in 18 healthy subjects who had received DAV132, uncoated formulated activated charcoal (FAC) or water 16 and 8 hours before, concomitantly with the probe drugs, and 8 hours thereafter. The AUC0-96 h of amoxicillin was reduced by more than 70% when it was taken with FAC, but bioequivalent when it was taken with water or DAV132. By contrast, the AUC0-96 h of sulfapyridine was reduced by more than 90% when administered with either FAC or DAV132 in comparison with water. The results show that DAV132 can selectively adsorb drug compounds in the proximal colon, without interfering with drug absorption in the proximal small intestine, thereby constituting a proof of concept that DAV132 actually functions in humans.

  18. Synthesis of a Crushed Fullerene C60H24 through Sixfold Palladium-Catalyzed Arylation. (United States)

    Dorel, Ruth; de Mendoza, Paula; Calleja, Pilar; Pascual, Sergio; González-Cantalapiedra, Esther; Cabello, Noemí; Echavarren, Antonio M


    The synthesis of a new C3v -symmetric crushed fullerene C60H24 (5) has been accomplished in three steps from truxene through sixfold palladium-catalyzed intramolecular arylation of a syn-trialkylated truxene precursor. Laser irradiation of 5 induces cyclodehydrogenation processes that result in the formation of C60, as detected by LDI-MS.

  19. Synthesis of a Crushed Fullerene C60H24 through Sixfold Palladium‐Catalyzed Arylation (United States)

    Dorel, Ruth; de Mendoza, Paula; Calleja, Pilar; Pascual, Sergio; González‐Cantalapiedra, Esther; Cabello, Noemí


    The synthesis of a new C 3v‐symmetric crushed fullerene C60H24 (5) has been accomplished in three steps from truxene through sixfold palladium‐catalyzed intramolecular arylation of a syn‐trialkylated truxene precursor. Laser irradiation of 5 induces cyclodehydrogenation processes that result in the formation of C60, as detected by LDI‐MS. PMID:27774038

  20. Surface Energy of C60 and the Interfacial Interactions in Aqueous Systems (United States)

    The surface free energy components of C60 powder in the form of compressed pellets were determined by sessile drop contact angle measurements. Based on van Oss-Chaudhury-Good model to Young-Dupre equation, the surface energy of C60 and the contributions of the apolar (Lifshitz-v...

  1. Anion-Dependent Aggregate Formation and Charge Behavior of Colloidal Fullerenes (n-C60) (United States)

    The fate and transport of colloidal fullerenes (n-C60) in the environment is likely to be guided by electrokinetic and aggregation behavior. In natural water bodies inorganic ions exert significant effects in determining the size and charge of n-C60 nanoparticles. Although the ef...


    Institute of Scientific and Technical Information of China (English)

    Fang Yun-tuan; Luo Cheng-lin


    We report the tight-binding molecular dynamics simulations of C60 impacting on a graphite (0001) surface with different incident energy. The simulations provide detailed characterizations of the microscopic processes occurring during the collisions and show insight into the deposition mechanisms of C60 on semiconductor substrate.

  3. Effects of C60 nanoparticle exposure on earthworms (Lumbricus rubellus) and implications for population dynamics

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Baveco, J.M.; Hout, van der A.; Rietjens, I.M.C.M.; Brink, van den N.W.


    Effects of C60 nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C60 exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model ef

  4. Chiral Supramolecular Self-Assembly of 2,2’:6’,2”-TERPYRIDINE-4’-CARBOXYLIC Acid Molecules Chemically Adsorbed on Cu(111) (United States)

    Jiang, Danfeng; Lu, Yan; Ling, Jie; Leng, Xinli; Liu, Xiaoqing; Wang, Li


    In this paper, large-area chiral supramolecular self-assembly of 2,2’:6’,2”-terpyridine-4’-carboxylic acid (C16H11N3O2; Y) molecules on Cu(111) is studied using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The basic building blocks of such a self-assembled monolayer are triangular vortex-shaped supramolecular structures containing three twisted Y molecules. Chirality is maintained and transferred from one vortex to the adjacent vortex in successive molecular domains within the same atomic terrace. The twisted Y molecule, bridging two nearest-neighbor Cu atoms, is stabilized by symmetric Cu-O bonds on the surface. The near perpendicularity of these bonds to the surface is the main reason for the formation of “standing-up” Y molecules.

  5. Structure and properties of Li@C60-PF6 endofullerene complex (United States)

    Srivastava, Ambrish Kumar; Kumar, Abhishek; Misra, Neeraj


    Li@C60 is a prototype endofullerene, which has been widely studied. Employing density functional theory we study the interaction of Li@C60 with PF6 superhalogen, which leads to the formation of Li@C60-PF6 endofullerene complex. The spectral properties such as infrared and UV-visible spectra have been calculated, which agree well with corresponding experimental data. The vibrational assignments and electronic transitions in the complex have been explored. We have noticed that this complex is stabilized by charge transfer from Li@C60 to PF6, which results in its large dipole moment (20 Debye), high mean polarizability (494 a.u.) and significant mean hyperpolarizability (1500 a.u.). We, therefore, believe that Li@C60-PF6 endofullerene complex might attract further attention for their possible electrooptical applications due to its enhanced nonlinear optical properties.

  6. Optical properties in 1D photonic crystal structure using Si/C60 multilayers

    Institute of Scientific and Technical Information of China (English)

    Chen Jing; Tang Jiyu; Han Peide; Chen Junfang


    The feasibility of using Si/C60 mulfilayer films as one-dimensional(1D)photonie band gap crystals was investigated by theoretical calculations using a transfer matrix method(TMM).The response has been studied both within and out of the periodic plane of Si/C60 multilayers.It is found that Si/C60 multilayer films show incomplete photonic band gap(PBG)behavior in the visible frequency range.The fabricated Si/C60 multilayers with two pairs of 70 am C60 and 30 nm Si layers exhibit a PBG at central wavelength of about 600 nm.and the highest reflectivity call reach 99%.As a consequence,this photonic crystal may be important for fabricating a photonic crystal with an incomplete band gap in the visible frequency range.

  7. Heterostructures based on graphene and MoS2 layers decorated by C60 fullerenes (United States)

    Chernozatonskii, Leonid A.; Kvashnin, Alexander G.; Sorokin, Pavel B.


    Here we present a comprehensive investigation of various novel composite structures based on graphene (G) and molybdenum disulphide (MoS2) monolayers decorated by C60 fullerenes, which can be successfully applied in photovoltaics as a solar cell unit. Theoretical studies of the atomic structure, stability and electronic properties of the proposed G/C60, MoS2/C60 and G/MoS2/C60/G nanostructures were carried out. We show that making the G/MoS2/C60/G heterostructure from the 2D films considered here will lead to the appearance of particular properties suitable for application in photovoltaics due to the broad energetic region of high electronic density of states.

  8. Coherence of Auger and inter-Coulombic decay processes in the photoionization of Ar@C60 versus Kr@C60

    CERN Document Server

    Magrakvelidze, Maia; Javani, Mohammad H; Madjet, Mohamed E; Manson, Steven T; Chakraborty, Himadri S


    For the asymmetric spherical dimer of an endohedrally confined atom and a host fullerene, an innershell vacancy of either system can decay through the continuum of an outer electron hybridized between the systems. Such decays, viewed as coherent superpositions of the single-center Auger and two-center inter-Coulombic (ICD) amplitudes, are found to govern leading decay mechanisms in noble-gas endofullerenes, and are likely omnipresent in this class of nanomolecules. A comparison between resulting autoionizing resonances calculated in the photoionization of Ar@C60 and Kr@C60 exhibits details of the underlying processes.

  9. Inhibition of DNA restrictive endonucleases and Taq DNA polymerase by trimalonic acid C60

    Institute of Scientific and Technical Information of China (English)

    YANG XinLin; CHEN Zhe; MENG XianMei; LI Bo; TAN Xin


    Activities of trimalonic acid fullerene (TMA C60) on DNA restrictive enzymatic reaction were investigated by using two restrictive endonucleases Hind III and EcoR I and plasmid pEGFP-N1 with single restrictive site for both enzymes. Meanwhile,TMA C60 was also tested to clarify its effects on polymerase chain reaction (PCR) with the catalyst of Taq DNA polymerase and the template of plasmid pEGFP-N1. The products from restrictive reactions or PCR were detected by agarose gel electrophoresis. It was found that the product amounts from restrictive reactions or PCR decreased significantly with addition of TMA C60. The inhibition by TMA C60 was dose-dependent and IC50 values for reactions of Hind III,EcoR I and PCR were 16.3,6.0 and 6.0 μmol/L,respectively. Addition of two scavengers of reactive oxygen species (ROS),L-ascorbic acid-2-phosphate ester magnesium and sodium azide at the concentrations of 2―10 mmol/L did not antagonize the activities of TMA C60 against PCR and two restrictive reactions. However,increase of Taq DNA polymerase amounts in PCR system antagonized the activities of TMA C60. These data implied that TMA C60 was able to inhibit the activities of the three above-mentioned enzymes involved in DNA metabolism,and that this inhibition probably did not correlate to ROS.

  10. Electron elastic scattering off polarizable $A$@C$_{60}$: The complete study within a particular theory

    CERN Document Server

    Dolmatov, V K; Chernysheva, L V


    A deeper insight into electron elastic scattering off endohedral fullerenes $A$@C$_{60}$ is provided. The study accounts for polarization of both the encapsulated atom $A$ and C$_{60}$ cage by an incident electron. It is carried out in the framework of the combination of both a model and the first-principle approximations. A core principle of the model is that the C$_{60}$ cage itself is presented by an attractive spherical potential of a certain inner radius, thickness, and depth. The main idea of the first-principle approximation is that the polarization of $A$@C$_{60}$ by an incident electron is accounted with the help of the Dyson equation for the self-energy part of the Green's function of an incident electron. Calculations are performed for, and comparison is made between the individual cases: (a) when $A$@C$_{60}$ is regarded as a static system, (b) when C$_{60}$ is a static cage, but the encapsulated atom is polarizable, (c) when both C$_{60}$ and $A$ are polarized simultaneously but independently of ...

  11. Removal of aqueous nC60 fullerene from water by low pressure membrane filtration. (United States)

    Floris, R; Nijmeijer, K; Cornelissen, E R


    The potential environmental and health risks of engineered nanoparticles such as buckminsterfullerene C60 in water require their removal during the production of drinking water. We present a study focusing on (i) the removal mechanism and (ii) the elucidation of the role of the membrane pore size during removal of nC60 fullerene nanoparticle suspensions in dead-end microfiltration and ultrafiltration mimicking separation in real industrial water treatment plants. Membranes were selected with pore sizes ranging from 18 nm to 500 nm to determine the significance of the nC60 to membrane pore size ratio and the adsorption affinity between nC60 and membrane material during filtration. Experiments were carried out with a dead-end bench-scale system operated at constant flux conditions including a hydraulic backwash cleaning procedure. nC60 nanoparticles can be efficiently removed by low pressure membrane technology with smaller and, unexpectedly, also by mostly similar or larger pores than the particle size, although the nC60 filtration behaviour appeared to be different. The nC60 size to membrane pore size ratio and the ratio of the cake-layer deposition resistance to the clean membrane resistance, both play an important role on the nC60 filtration behaviour and on the efficiency of the backwash procedure recovering the initial membrane filtration conditions. These results become specifically significant in the context of drinking water production, for which they provide relevant information for an accurate selection between membrane processes and operational parameters for the removal of nC60 in the drinking water treatment.

  12. Effects of exchange-correlation potentials on the density functional description of C_60 versus C_240 photoionization

    CERN Document Server

    Choi, Jinwoo; Anstine, Dylan M; Madjet, Mohamed El-Amine; Chakraborty, Himadri S


    We study the photoionization properties of the C_60 versus C_240 molecule in a spherical jellium frame of density functional method. Two different approximations to the exchange-correlation (xc) functional are used: (i) The Gunnerson-Lundqvist parametrization [Phys. Rev. B 13, 4274 (1976)] with an explicit correction for the electron self-interaction (SIC) and (ii) a gradient-dependent augmentation of (i) by using the van Leeuwen and Baerends model potential [Phys. Rev. A 49, 2421 (1994)], in lieu of SIC, to implicitly restore electrons' asymptotic properties. Ground state results from the two schemes for both molecules show differences in the shapes of mean-field potentials and bound-level properties. The choice of a xc scheme also significantly alters the dipole single-photoionization cross sections obtained by an abinitio method that incorporates linear-response dynamical correlations. Differences in the structures and ionization responses between C_60 and C_240 uncover the effect of molecular size on the ...

  13. Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C 60 Solar Cells: Theoretical Insight into the Impact of Interface Geometry

    KAUST Repository

    Yi, Yuanping


    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C60 heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation and charge recombination have been evaluated for several geometrical configurations of the pentacene/C60 complex, which are relevant to bilayer and bulk heterojunctions. The results suggest that, irrespective of the actual pentacene-fullerene orientation, both pentacene-based and C60-based excitons are able to dissociate efficiently. Also, in the case of parallel configurations of the molecules at the pentacene/C60 interface, the decay of the lowest charge-transfer state to the ground state is calculated to be very fast; as a result, it can compete with the dissociation process into mobile charge carriers. Since parallel configurations are expected to be found more frequently in bulk heterojunctions than in bilayer heterojunctions, the performance of pentacene/C60 bulk-heterojunction solar cells is likely to be more affected by charge recombination than that of bilayer devices. © 2009 American Chemical Society.

  14. Analysis of C60 insertion into single wall carbon nanotube by molecular dynamics simulation (United States)

    Ishii, Takafumi; Esfarjani, Keivan; Hashi, Yuichi; Kawazoe, Yoshiyuki; Iijima, Sumio


    Classical molecular dynamics is used to simulate the insertion of C60 into a (10, 10) single wall nano tube (SWNT). We propose that the insertion process occurs through the open end of the tube. After insertion, the energy exchange between the C60 and the nanotube causes the kinetic energy of the former to decrease as it moves inside the tube. This kinetic energy loss is due to a "friction force" which we calculated for several insertion conditions. The binding energy of the C60 with the SWNT is due to Van der Waals interaction, and is found to be about 3.5 eV.

  15. Nonequilibrium electron-vibration coupling and conductance fluctuations in a C60 junction

    DEFF Research Database (Denmark)

    Ulstrup, Søren; Frederiksen, Thomas; Brandbyge, Mads


    We investigate chemical bond formation and conductance in a molecular C60 junction under finite bias voltage using first-principles calculations based on density functional theory and nonequilibrium Green's functions (DFT-NEGF). At the point of contact formation we identify a remarkably strong...... coupling between the C60 motion and the molecular electronic structure. This is only seen for positive sample bias, although the conductance itself is not strongly polarity dependent. The nonequilibrium effect is traced back to a sudden shift in the position of the voltage drop with a small C60...

  16. Photoelectric Properties of Soluble ZnPc-Epoxy Derivative Doped with C60

    Institute of Scientific and Technical Information of China (English)

    Jingwei CHEN; Yue SHEN; Jiancheng ZHANG; Feng GU; Jinzhuan ZHU; Yiben XIA


    A kind of soluble phthalocyanine derivative (ZnPc-epoxy derivative) was synthesized, and the influence of C60 on the photoelectric properties of the derivative was studied. The results of ultraviolet-visible (UV-Vis)spectra show that the absorption of the complex is larger than that of the ZnPc-epoxy derivative at B belt.But compared with the derivative, the absorption of the complex decreased at Q belt. The fluorescence spectra show that C60 takes role as annihilation in ZnPc-epoxy derivative. Photo-current tests show that the ZnPc-epoxy derivative-C60 film exhibits increasing photoconductive property.

  17. Preparation and Photoemission Spectra of Rb3C60 Single-Crystal Thin Films

    Institute of Scientific and Technical Information of China (English)

    李宏年; 吴太权; 陈晓; 李海洋; 鲍世宁; 徐亚伯; 钱海杰; 易卜拉欣奎热西; 刘风琴


    Rb3 C60 single-crystal thin films were prepared on the cleaved (111) surface of C60 single crystal. The photoemission spectrum line shapes of the lowest unoccupied molecular orbital (LUMO) derived band at room temperature and 150K were established by synchrotron radiation photoemission spectrum measurements. The density of states near the Fermi level was distinctly affected by temperature. No less than six sub-peaks of the LUMOband were observed even at room temperature. The existence of so many sub-peaks offered the opportunities to analyse in more detail the orientational structure and the electron-Boson interactions of the narrow-band metallic Rb3 C60 .

  18. Antiferromagnetic resonance in the Mott insulator fcc-Cs3C60. (United States)

    Suzuki, Yuta; Shibasaki, Seiji; Kubozono, Yoshihiro; Kambe, Takashi


    The magnetic ground state of the fcc phase of the Mott insulator Cs3C60 was studied using a low-temperature electron spin resonance technique, and antiferromagnetic resonance (AFMR) below 1.57 K was directly observed at ambient pressure. The AFMR modes for the fcc phase of Cs3C60 were investigated using a conventional two-sublattice model with uniaxial anisotropy, and the spin-flop field was determined to be 4.7 kOe at 1.57 K. The static magnetic exchange interactions and anisotropy field for fcc-Cs3C60 were also estimated.

  19. Density functional study on a light-harvesting carotenoid-porphyrin-C60 molecular triad in explicit solvent (United States)

    Diaz, Carlos; Baruah, Tunna; Zope, Rajendra

    We investigate the effect of solvent on the electronic structure of a biomimetic molecular triad that shows photoinduced charge transfer in laboratory. The supramolecular triad contains three different units - C60, porphyrin, and beta-carotenoid. We have performed classical molecular dynamics simulation of the triad surrounded by 15000 water molecules using NAMD for 20 nanoseconds. Subsequently, we performed an all-electron density functional calculations (DFT) using large basis sets on the 50 snap-shots taken from the molecular dynamics simulation. The solvent effects in the DFT calculations are treated using both the explicit water molecules as well as using the point charge representation of water. The excitation energies and absorption spectra show that the polar solvent induces significant changes in the electronic structure of the triad.

  20. Enhanced Raman spectroscopy of molecules adsorbed on carbon-doped TiO₂ obtained from titanium carbide: a visible-light-assisted renewable substrate. (United States)

    Kiran, Vankayala; Sampath, Srinivasan


    Titanium carbide (TiC) is an electrically conducting material with favorable electrochemical properties. In the present studies, carbon-doped TiO(2) (C-TiO(2)) has been synthesized from TiC particles, as well as TiC films coated on stainless steel substrate via thermal annealing under various conditions. Several C-TiO(2) substrates are synthesized by varying experimental conditions and characterized by UV-visible spectroscopy, photoluminescence, X-ray diffraction, and X-ray photoelectron spectroscopic techniques. C-TiO(2) in the dry state (in powder form as well as in film form) is subsequently used as a substrate for enhancing Raman signals corresponding to 4-mercaptobenzoic acid and 4-nitrothiophenol by utilizing chemical enhancement based on charge-transfer interactions. Carbon, a nonmetal dopant in TiO(2), improves the intensities of Raman signals, compared to undoped TiO(2). Significant dependence of Raman intensity on carbon doping is observed. Ameliorated performance obtained using C-TiO(2) is attributed to the presence of surface defects that originate due to carbon as a dopant, which, in turn, triggers charge transfer between TiO(2) and analyte. The C-TiO(2) substrates are subsequently regenerated for repetitive use by illuminating an analyte-adsorbed substrate with visible light for a period of 5 h.

  1. Reliable structural, thermodynamic, and spectroscopic properties of organic molecules adsorbed on silicon surfaces from computational modeling: the case of glycine@Si(100). (United States)

    Carnimeo, Ivan; Biczysko, Malgorzata; Bloino, Julien; Barone, Vincenzo


    Chemisorption of glycine on Si(100) has been studied by an integrated computational strategy based on perturbative anharmonic computations employing geometries and harmonic force fields evaluated by hybrid density functionals coupled to purposely tailored basis sets. It is shown that such a strategy allows the prediction of spectroscopic properties of isolated and chemisorbed molecules with comparable accuracy, paving the route toward a detailed analysis of surface-induced changes of glycine vibrational spectra.

  2. Synchrotron radiation photoemission spectrum study on K3C60 film

    Institute of Scientific and Technical Information of China (English)

    李宏年; 徐亚伯; 鲍世宁; 李海洋; 何丕模; 钱海杰; 刘风琴; 奎热西·易卜拉欣


    K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.

  3. Evaluation of C60 secondary ion mass spectrometry for the chemical analysis and imaging of fingerprints. (United States)

    Sisco, Edward; Demoranville, Leonard T; Gillen, Greg


    The feasibility of using C60(+) cluster primary ion bombardment secondary ion mass spectrometry (C60(+) SIMS) for the analysis of the chemical composition of fingerprints is evaluated. It was found that C60(+) SIMS could be used to detect and image the spatial localization of a number of sebaceous and eccrine components in fingerprints. These analyses were also found to not be hindered by the use of common latent print powder development techniques. Finally, the ability to monitor the depth distribution of fingerprint constituents was found to be possible - a capability which has not been shown using other chemical imaging techniques. This paper illustrates a number of strengths and potential weaknesses of C60(+) SIMS as an additional or complimentary technique for the chemical analysis of fingerprints.

  4. Optimization of the Thermoelectric Figure of Merit in Crystalline C60 with Intercalation Chemistry. (United States)

    Kim, Jeong Yun; Grossman, Jeffrey C


    Crystalline C60 is an appealing candidate material for thermoelectric (TE) applications due to its extremely low thermal conductivity and potentially high electrical conductivity with metal atom intercalation. We investigate the TE properties of crystalline C60 intercalated with alkali and alkaline earth metals using both classical and quantum mechanical calculations. For the electronic structure, our results show that variation of intercalated metal atoms has a large impact on energy dispersions, which leads to broad tunability of the power factor. For the thermal transport, we show that dopants introduce strong phonon scattering into crystalline C60, leading to considerably lower thermal conductivity. Taking both into account, our calculations suggest that appropriate choice of metal atom intercalation in crystalline C60 could yield figures of merit near 1 at room temperature.

  5. Decoration of C60 nanorods with nickel and their magnetic properties

    Institute of Scientific and Technical Information of China (English)

    CHEN Ao; LIU BingBing; HOU YuanYuan; WEN GeHui; LIU DeDi; LU ShuangChen; LI ZePeng; LI XiangLin; ZOU YongGang; ZOU Bo; LI DongMei; CUI Tian; ZOU GuangTian


    We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel.

  6. Neutron Scattering Study of Na_2C_60 in (P,T)-Plane (United States)

    Trevino, S. F.; Yildirim, T.; Neumann, D. A.; Fischer, J. E.


    Na_2C_60 forms the simplest system to investigate various intermolecular interactions. Therefore, we have studied Na_2C_60 for 0 250 K and P > 1 kbar, the structure is distorted, qualitatively similar to suggested pressure induced polymer phase of Na_2RbC_60[1]. Here the peaks at low Q are significantly broaden while the higher Q peaks are almost completely smeared out. Inelastic neutron scattering measurements performed at T=150 K and with P=0 and 4 kbar did not show any new lattice modes in the range 100-200 cm-1, inconsistent with C_60 polymerization. Instead, we observed an excess of low energy states in the distorted phase, reminiscent of what is observed in glassy solids. fˇill [1] Q.Zhu, Phys. Rev. B 52, R723 (1995).

  7. Thermodynamic properties of solid face centered cubic Rb3C60 at high temperature and pressure (United States)

    Yang, W.; Sun, J. X.; Liu, H.; Yan, G. F.


    Analytic equation of state and thermodynamic quantities of solid fcc Rb3C60 are derived by using an analytic mean field potential method. For intermolecular forces, the double-exponential potential is utilized. Four potential parameters are determined by fitting experimental compression data of Rb3C60 up to 14 GPa at 296 K. Various physical quantities including isothermals, thermal expansion, isochoric heat capacity, Helmholtz free energy and internal energy are calculated and analyzed. Calculated results are consistent with available experimental data in literature. Furthermore, spinodal temperature for Rb3C60 is found to be 2,860 K. Results verify that analytic mean field potential method is a useful approach to consider the anharmonic effect at high temperatures. Numerous reasonable predictions and the change trend of the properties for Rb3C60 at high temperature and pressure have been given.

  8. Vibrational properties of polymer and quenched CsC{60} phases (United States)

    Sauvajol, J.-L.; Anglaret, E.; Chesnel, K.; Palpacuer, M.; Girard, A.; Moreac, A.; Ameline, J.-C.; Delugeard, Y.; Hennion, B.


    We report new results on the vibrational dynamics of polymer and quenched CSC{60} phases. Both the splitting and the structure of new activated lines of polymer CsC{60} are in agreement with the lowering of C{60} molecular symmetry from Ih to D{2h}. An inelastic neutron investigation on polymer and quenched CsC{60} is reported. It allows one to identify the vibrational signature of the low-temperature (T neutronique de la phase polymère et des phases obtenues par trempe a été réalisée. Elle a permis en particulier de déterminer la 'signature' vibrationnelle d'une phase ordonnée monomère à très basse température (T < 150 K) dans le CsC{60} trempé.

  9. Polymorphism control of superconductivity and magnetism in Cs(3)C(60) close to the Mott transition. (United States)

    Ganin, Alexey Y; Takabayashi, Yasuhiro; Jeglic, Peter; Arcon, Denis; Potocnik, Anton; Baker, Peter J; Ohishi, Yasuo; McDonald, Martin T; Tzirakis, Manolis D; McLennan, Alec; Darling, George R; Takata, Masaki; Rosseinsky, Matthew J; Prassides, Kosmas


    The crystal structure of a solid controls the interactions between the electronically active units and thus its electronic properties. In the high-temperature superconducting copper oxides, only one spatial arrangement of the electronically active Cu(2+) units-a two-dimensional square lattice-is available to study the competition between the cooperative electronic states of magnetic order and superconductivity. Crystals of the spherical molecular C(60)(3-) anion support both superconductivity and magnetism but can consist of fundamentally distinct three-dimensional arrangements of the anions. Superconductivity in the A(3)C(60) (A = alkali metal) fullerides has been exclusively associated with face-centred cubic (f.c.c.) packing of C(60)(3-) (refs 2, 3), but recently the most expanded (and thus having the highest superconducting transition temperature, T(c); ref. 4) composition Cs(3)C(60) has been isolated as a body-centred cubic (b.c.c.) packing, which supports both superconductivity and magnetic order. Here we isolate the f.c.c. polymorph of Cs(3)C(60) to show how the spatial arrangement of the electronically active units controls the competing superconducting and magnetic electronic ground states. Unlike all the other f.c.c. A(3)C(60) fullerides, f.c.c. Cs(3)C(60) is not a superconductor but a magnetic insulator at ambient pressure, and becomes superconducting under pressure. The magnetic ordering occurs at an order of magnitude lower temperature in the geometrically frustrated f.c.c. polymorph (Néel temperature T(N) = 2.2 K) than in the b.c.c.-based packing (T(N) = 46 K). The different lattice packings of C(60)(3-) change T(c) from 38 K in b.c.c. Cs(3)C(60) to 35 K in f.c.c. Cs(3)C(60) (the highest found in the f.c.c. A(3)C(60) family). The existence of two superconducting packings of the same electronically active unit reveals that T(c) scales universally in a structure-independent dome-like relationship with proximity to the Mott metal-insulator transition

  10. Ground State Reactions of nC60 with Free Chlorine in Water. (United States)

    Wu, Jiewei; Benoit, Denise; Lee, Seung Soo; Li, Wenlu; Fortner, John D


    Facile, photoenhanced transformations of water-stable C60 aggregates (nC60) to oxidized, soluble fullerene derivatives, have been described as key processes in understanding the ultimate environmental fate of fullerene based materials. In contrast, fewer studies have evaluated the aqueous reactivity of nC60 during ground-state conditions (i.e., dark conditions). Herein, this study identifies and characterizes the physicochemical transformations of C60 (as nC60 suspensions) in the presence of free chlorine, a globally used chemical oxidant, in the absence of light under environmentally relevant conditions. Results show that nC60 undergoes significant oxidation in the presence of free chlorine and the oxidation reaction rates increase with free chlorine concentration while being inversely related to solution pH. Product characterization by FTIR, XPS, Raman Spectroscopy, TEM, XRD, TOC, collectively demonstrates that oxidized C60 derivatives are readily formed in the presence of free chlorine with extensive covalent oxygen and even chlorine additions, and behave as soft (or loose) clusters in solution. Aggregation kinetics, as a function of pH and ionic strength/type, show a significant increase in product stabilities for all cases evaluated, even at pH values approaching 1. As expected with increased (surface) oxidation, classic Kow partitioning studies indicate that product clusters are relatively more hydrophilic than parent (reactant) nC60. Taken together, this work highlights the importance of understanding nanomaterial reactivity and the identification of corresponding stable daughter products, which are likely to differ significantly from parent material properties and behaviors.

  11. The C60(FeCp22-Based Cell Proliferation Accelerator

    Directory of Open Access Journals (Sweden)

    Andrei Soldatov


    Full Text Available We studied structural and magnetic proprieties of the fulleride C60(FeCp22. The influence of fulleride particles on the cell proliferative activity was also investigated. We found that the proliferative activity of the RINmF5 cells increases (53% versus control in presence of the C60(FeCp22 nanosized particles. Moreover, it was registered that the cell culture became multilayered and secreted basophile matrix.

  12. Biodistribution and tumor uptake of C60(OH) x in mice (United States)

    Ji, Zhi Qiang; Sun, Hongfang; Wang, Haifang; Xie, Qunying; Liu, Yuangfang; Wang, Zheng


    Radiolabeling of fullerol, 125I-C60(OH) x , was performed by the traditional chloramine-T method. The C-I covalent bond in I-C60(OH) x was characterized by X-ray photoelectron spectroscopy (XPS) that was sufficiently stable for in vivo study. Laser light scattering spectroscopy clearly showed that C60(OH) x aggregated to large nanoparticle clumps with a wide range of distribution. The clumps formed were also visualized by transmission electron microscope (TEM). We examined the biodistribution and tumor uptake of C60(OH) x in five mouse bearing tumor models, including mouse H22 hepatocarcinoma, human lung giantcellcarcinoma PD, human colon cancer HCT-8, human gastric cancer MGC803, and human OS732 osteosarcoma. The accumulation ratios of 125I-C60(OH) x in mouse H22 hepatocarcinoma to that in normal muscle tissue (T/N) and blood (T/B) at 1, 6, 24 and 72 h, reveal that 125I-C60(OH) x gradually accumulates in H22 tumor, and retains for a quite long period (e.g., T/N 3.41, T/B 3.94 at 24 h). For the other four tumor models, the T/N ratio at 24 h ranges within 1.21-6.26, while the T/B ratio ranges between 1.23 and 4.73. The accumulation of C60(OH) x in tumor is mostly due to the enhanced permeability and retention effect (EPR) and the phagocytosis of mononuclear phagocytes. Hence, C60(OH) x might serve as a photosensitizer in the photodynamic therapy of some kinds of tumor.

  13. 吸附气体小分子石墨烯的紫外光谱的第一性原理研究%First-principles atudy of small molecules adsorbed gas ultraviolet spectra of grapheme

    Institute of Scientific and Technical Information of China (English)

    许晓刚; 龙超云; 李涛


    为研究吸附气体小分子的石墨烯紫外光谱,可以能够灵敏准确的测量出石墨烯吸附的气体小分子的种类。本文采用杂化密度泛函B3LYP方法在6-31G*的基组上优化了吸附CO,H2O,CH4气体分子的石墨烯的稳定结构。采用杂化密度泛函B3LYP方法在6-31+G*的基组上计算了吸附CO,H2O,CH4气体分子的石墨烯的稳定状态下的电子结构。基于Gelius模型,算出其紫外光谱。这为通过光学手段研究和制备高灵敏度的气体小分子探测器探索了一条新的道路。%For the study of smal molecules adsorbed gas ultraviolet spectrum of graphene,may be able to accurately measure the species sensitive graphenesmal gas molecules adsorbed.Inthispaper,hybrid density functional B3LY Pmethod on the 6- 31G*basis sets optimized the stable structure of adsorptionCO,H2O,CH4g asmoleculesgrapheme.Using hybrid density functional B3LY Pmethod on a 6- 31+G*basisset to calculate the adsorption of CO,H2O,CH4 gas molecules graphene the electronic structure of steady state.Based Geliusmodel to calculate its ultraviolet spectrum.Itis by means of re-search and preparation of high optical sensitivity of smal molecule gas detectors to explore a new path.

  14. Buckminsterfullerene's (C60) octanol-water partition coefficient (Kow) and aqueous solubility. (United States)

    Jafvert, Chad T; Kulkarni, Pradnya P


    To assess the risk and fate of fullerene C60 in the environment, its water solubility and partition coefficients in various systems are useful. In this study, the log Kow of C60 was measured to be 6.67, and the toluene-water partition coefficient was measured at log Ktw = 8.44. From these values and the respective solubilities of C60 in water-saturated octanol and water-saturated toluene, C60's aqueous solubility was calculated at 7.96 ng/L(1.11 x 10(-11) M) for the organic solvent-saturated aqueous phase. Additionally, the solubility of C60 was measured in mixtures of ethanol-water and tetrahydrofuran-water and modeled with Wohl's equation to confirm the accuracy of the calculated solubility value. Results of a generator column experiment strongly support the hypothesis that clusters form at aqueous concentrations below or near this calculated solubility. The Kow value is compared to those of other hydrophobic organic compounds, and bioconcentration factors for C60 were estimated on the basis of Kow.

  15. Preparation of C60 Nanowhiskers-SnO2 Nanocomposites and Photocatalytic Degradation of Organic Dyes. (United States)

    Park, Hae Soo; Ko, Weon Bae


    C60 nanowhiskers were prepared using a liquid-liquid interfacial precipitation (LLIP) method. Tin oxide (SnO2) nanoparticles were synthesized by a reaction of tin (IV) chloride pentahydrate with ammonium nitrate in an electric furnace. The C60 nanowhiskers-SnO2 nanocomposites were calcined in an electric furnace at 700 °C under an inert argon gas atmosphere for 2 h. The crystallinity, morphology and optical properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and UV-vis spectrophotometry. The photocatalytic activity of the C60 nanowhiskers-SnO2 nanocomposites in the degradation of the organic dyes, such as methylene blue, methyl orange, rhodamine B, and brilliant green, under ultraviolet light at 254 nm by UV-vis spectrophotometry was evaluated and compared with that of C60 nanowhiskers and SnO2 nanoparticles. The experimental results showed that C60 nanowhiskers-SnO2 nanocomposites exhibited remarkably higher photocatalytic degradation of organic dyes compared to C60 nanowhiskers and SnO2 nanoparticles.

  16. Potential Suppressive Effects of Two C60 Fullerene Derivatives on Acquired Immunity (United States)

    Hirai, Toshiro; Yoshioka, Yasuo; Udaka, Asako; Uemura, Eiichiro; Ohe, Tomoyuki; Aoshima, Hisae; Gao, Jian-Qing; Kokubo, Ken; Oshima, Takumi; Nagano, Kazuya; Higashisaka, Kazuma; Mashino, Tadahiko; Tsutsumi, Yasuo


    The therapeutic effects of fullerene derivatives on many models of inflammatory disease have been demonstrated. The anti-inflammatory mechanisms of these nanoparticles remain to be elucidated, though their beneficial roles in allergy and autoimmune diseases suggest their suppressive potential in acquired immunity. Here, we evaluated the effects of C60 pyrrolidine tris-acid (C60-P) and polyhydroxylated fullerene (C60(OH)36) on the acquired immune response in vitro and in vivo. In vitro, both C60 derivatives had dose-dependent suppressive effects on T cell receptor-mediated activation of T cells and antibody production by B cells under anti-CD40/IL-4 stimulation, similar to the actions of the antioxidant N-acetylcysteine. In addition, C60-P suppressed ovalbumin-specific antibody production and ovalbumin-specific T cell responses in vivo, although T cell-independent antibodies responses were not affected by C60-P. Together, our data suggest that fullerene derivatives can suppress acquired immune responses that require T cells.

  17. Transmission properties of C60 ions through micro- and nano-capillaries (United States)

    Tsuchida, Hidetsugu; Majima, Takuya; Tomita, Shigeo; Sasa, Kimikazu; Narumi, Kazumasa; Saitoh, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Hirata, Koichi; Shibata, Hiromi; Itoh, Akio


    We apply the capillary beam-focusing method for the C60 fullerene projectiles in the velocity range between 0.14 and 0.2 a.u. We study the C60 transmission properties through two different types of capillaries: (1) borosilicate glass microcapillary with an outlet diameter of 5.5 μm, and (2) Al2O3 multi-capillary foil with a pore size of about 70 nm and a high aspect ratio of about 750. We measured the transmitted particle composition by using the electrostatic deflection method combined with the microchannel plate imaging technique. For the experiments with the single microcapillary, the main transmission component is found to be primary C60 beams that are focused in the area equal to the capillary outlet diameter. Minor components are charge-exchanged C60 ions and charged or neutral fragments (fullerene-like C60-2m and small Cn particles), and their fractions decrease with decreasing the projectile velocity. It is concluded that the C60 transmission fraction is considerably high for both types of the capillaries in the present velocity range.

  18. Development and Characterization of Biocompatible Fullerene [C60]/Amphiphilic Block Copolymer Nanocomposite

    Directory of Open Access Journals (Sweden)

    Alok Chaurasia


    Full Text Available We report a supramolecular process for the synthesis of well-defined fullerene (C60/polymer colloid nanocomposites in an aqueous solution via complex formation. A biocompatible triblock poly(4-vinylpyridine-b-polyethylene-b-poly(4-vinylpyridine, P4VP8-b-PEO105-b-P4VP8, was synthesized by atom transfer radical polymerization. The block copolymer formed complexes with C60 in toluene and resulted in fullerene assembly in cluster form. Nanocomposite dispersion in an aqueous solution could be obtained using an aged solution of the polymer/C60/toluene solution by a solvent evaporation technique. The UV-Vis and FTIR spectroscopy confirmed the complex formation of fullerene with the polymer which plays a significant role in controlling the PDI and size of polymer/C60 micelles in the toluene solution. The particle size and morphology of P4VP8-b-PEO105-b-P4VP8 and P4VP8-b-PEO105-b-P4VP8/C60 mixture were studied by dynamic light scattering (DLS and transmission electron microscopy (TEM. In a cytotoxicity test, both pure polymer and the resulting polymer/C60 composite in water showed more than 90% cell viability at 1 mg/mL concentration.

  19. Fabrication of filamentary potassium-doped C 60 superconductors by suspension spinning method (United States)

    Goto, T.; Maezawa, M.


    This paper describes the preparation of filamentary potassium-doped C 60 superconductors prepared by the suspension spinning method. Commercial C 60 powder was suspended in mixed poly(vinyl alcohol) solution of dimethyl sulfoxide and hexamethylphosphoric triamide (sample A). The viscous suspension was extruded as a filament into a precipitating medium of methyl alcohol and coiled on a drum. The filamentary sample was also prepared by the suspension spinning by using polyacrylonitrile solution of N, N-dimethylformamide (sample B). The samples were pyrolyzed to remove volatile components. Doping of potassium for the samples was prepared as following: At first, powder samples of nominal composition K 6C 60 was prepared by reaction of C 60 with excess potassium. The K 6C 60 powder and filamentary sample with stoichiometric ratio of K 3C 60 were placed in Pyrex glass tubes and vacuum-sealed and heated at 250 °C for 36 h. SQUID measurement shows the superconductivity of sample B with Tc=18 K. On the other hand, the superconductivity more than 2 K was not detected for sample A.

  20. Non-detection of C60 fullerene at two mass extinction horizons (United States)

    Carrasquillo, Anthony J.; Cao, Changqun; Erwin, Douglas H.; Summons, Roger E.


    Fullerene (C60) have been reported in a number of geologic samples and, in some cases, attributed to carbonaceous materials delivered during bolide impact events. The extraction and detection of C60 poses significant analytical challenges, and some studies have been called into question due to the possibility of C60 forming in situ. Here, we extracted samples taken from the Permian-Triassic boundary section in Meishan, South China and the Cretaceous-Paleogene boundary exposed at Stevns Klint, Denmark, and analyzed the residues using a fast and reliable method for quantifying C60. Extraction of both whole rock and completely demineralized samples were completed under conditions that previously yielded C60 as well as using an optimized approach based on recent literature reports. These extracts were analyzed using mass spectrometry with the soft-ionization techniques, atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI), which have not been shown to form fullerenes in-situ. In no case were we able to detect C60, nor could we corroborate previous reports of its occurrence in these sediments, thereby challenging the utility of fullerene as a proxy for bolide impacts or mass extinction events.

  1. C60-Based Ebselen Derivative: Synthesis and Enhanced Protective Effect on Mouse Thymus Cells

    Institute of Scientific and Technical Information of China (English)

    LIU,Xu-Feng; GUAN,Wen-Chao; KE,Wen-Shan


    A C60-based ebselen derivative 3 was synthesized through a Bingel cyclopropanation of C60 with the ebselen malonate 2. It was obtained in a three-step synthesis starting from 2-(chloroseleno)benzoyl chloride and 2-(2-aminoethoxy)ethanol, in a 42% yield (based on consumed C60). Its structure was characterized by 1H NMR,13C NMR, IR, FAB-MS, and elemental analyses techniques. To verify that the C60-based ebselen derivative 3 had enhanced effect on viability of mouse thymus cells, the C60 derivative 4 and ebselen derivative 2 were selected to treat the mouse thymus cells using the same procedures as those with the C60-based ebselen derivative 3. The result shows that MTT(OD) values of compound 3 treated groups (0.335 ±0.021) were all higher than those of compound 4 (0.283±0.031) and compound 2 (0.247±0.025) treated groups, indicating that the compound 3 has an advantage over compounds 2 and 4 in promoting the viability of the mouse thymus cell.

  2. Band structure of fcc-C60 solid state crystal study

    Directory of Open Access Journals (Sweden)

    S Javanbakht


    Full Text Available We studied the architecture of the C60 cluster to drive its atomic positions which can be seen at room temperature. We then used the obtained carbon positions as a basis set for the fcc structure to construct the fcc-C60 compound. Self consistent calculations were performed based on the density functional theory (DFT utilizing the accurate WIEN2K code to solve the single-particle Kohen-Sham equation within the augmented plane waves plus local orbital (APW+lo method. The cohesive energy has been found to be 1.537 eV for the fcc-C60 . The calculated small cohesive energy that results from the weak Van der Waals-London interactions among a C60 cluster with its nearest neighbors is in good agreement with experiment. The electron densities of states (DOSs were calculated for a C60 macromolecule as well as the fcc-C60 compound and the results were compared with each other. The band gap from DOS calculations has been found to be 0.7 eV. Band structures were also calculated within the generalized gradient approximation (GGA. The band structure calculation results in 1.04 eV for the direct band gap. Two kinds of σ and π bonds were determined in the band structure. Our results are in good agreement with experiment and pseudopotential calculations.

  3. C70 self-assembly on In- and Tl-adsorbed Si(111)√{ 3 } ×√{ 3 } -Au surfaces (United States)

    Olyanich, D. A.; Mararov, V. V.; Utas, T. V.; Zotov, A. V.; Saranin, A. A.


    Behavior of C70 fullerenes adsorbed onto the In- and Tl-modified Si(111)√{ 3 } ×√{ 3 } -Au surfaces at room temperature (RT) and 112 K has been studied using scanning tunneling microscopy observations and compared with the known results for the C60s on the same surfaces. During island growth at 112 K, both C70 and C60 are characterized by the same critical island size i=1. The difference is in an island shape as C70s tend to form chain-like islands built of double or triple molecular rows along the [ 1 bar 10 ] Si(111) substrate directions. At RT, C70s have a lower mobility as compared to C60s. In contrast to the C60 magic islands, the C70 islands do not demonstrate any strong preference for specific shapes or sizes. Extended C70 arrays exhibit a stripe-like 3×1 reconstruction where a single row of bright fullerenes mediated by a double row of dim fullerenes. The reconstruction is due to the different orientations of C70s within the layer which does not relate to the structure of the underlying Au/Si(111) substrate. This is in contrast to the hexagonal reconstructions of C60s where the bright fullerenes occupy the specific adsorption site atop Au trimers. The difference in the behavior of C70 and C60 is plausibly affected by the non-spherical shape of C70 molecule and a greater intermolecular C70-C70 interaction.

  4. Electric-dipole-coupled H2O@C60 dimer: Translation-rotation eigenstates from twelve-dimensional quantum calculations (United States)

    Felker, Peter M.; Bačić, Zlatko


    We report on variational solutions to the twelve-dimensional (12D) Schrödinger equation appertaining to the translation-rotation (TR) eigenstates of H2O@C60 dimer, associated with the quantized "rattling" motions of the two encapsulated H2O molecules. Both H2O and C60 moieties are treated as rigid and the cage-cage geometry is taken to be fixed. We consider the TR eigenstates of H2O@C60 monomers in the dimer to be coupled by the electric dipole-dipole interaction between water moieties and develop expressions for computing the matrix elements of that interaction in a dimer basis composed of products of monomer 6D TR eigenstates reported by us recently [P. M. Felker and Z. Bačić, J. Chem. Phys. 144, 201101 (2016)]. We use these expressions to compute TR Hamiltonian matrices of H2O@C60 dimer for two values of the water dipole moment and for various dimer geometries. 12D TR eigenstates of the dimer are then obtained by filter diagonalization. The results reveal two classes of eigenstates, distinguished by the leading order (first or second) at which dipole-dipole coupling contributes to them. The two types of eigenstates differ in the general magnitude of their dipole-induced energy shifts and in the dependence of those shifts on the value of the water dipole moment and on the distance between the H2O@C60 monomers. The dimer results are also found to be markedly insensitive to any change in the orientations of the C60 cages. Finally, the results lend some support for the interpretation that electric dipole-dipole coupling is at least partially responsible for the apparent reduced-symmetry environment experienced by H2O in the powder samples of H2O@C60 [K. S. K. Goh et al., Phys. Chem. Chem. Phys. 16, 21330 (2014)], but only if the water dipole is taken to have a magnitude close to that of free water. The methodology developed in the paper is transferable directly to the calculation of TR eigenstates of larger H2O@C60 assemblies, that will be required for more

  5. C60与石墨烯复合材料性能的理论研究%Theoretical Study of C60/ Graphene Hybrid Material

    Institute of Scientific and Technical Information of China (English)

    易佳; 王昭; 毛峰; 黄祥平; 魏慧丽; 张昌远



  6. The Dynamics and Structures of Adsorbed Surfaces

    DEFF Research Database (Denmark)

    Nielsen, M; Ellenson, W. D.; McTague, J. P.


    of molecules such as NH3 or the internal modes of adsorbed molecules such as C4H10. Neutron scattering measurements where substrates other than graphite products are used as the adsorbents will not be reviewed here. However, the power of the technique will be demonstrated in an example of H2 physisorbed...... to activated alumina and in an example where hydrogen is chemisorbed to Raney nickel...

  7. Ab-inito calculation of energy level alignment and vacuum level shift at CuPc/C60 interfaces (United States)

    Sai, Na; Zhu, Xiaoyang; Chelikowsky, James; Leung, Kevin


    The alignment of the donor and acceptor enegy levels is of crucial importance for organic photovotaic performance. We investigate the interfaical electronic structure and energy level alignment of copper phthalocyanine (CuPc)/fullerene (C60) using ab-inito density functional theory calculations including van der Waals interactions and hybrid density functionals. We show that energy level alignment critically depends on the standing-up and lying-down orientation of the CuPc molecules relative to C60 at the interface. We calculate the magnitude of the interface dipole at different molecular orientations and compare them to the vacuum level shift observed in photoemission spectroscopy. The validity of existing theoretical models which invoke charge transfer on this organic interface will be discussed in light of our predictions. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Deparment of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  8. Molecularly Imprinted Filtering Adsorbents for Odor Sensing

    Directory of Open Access Journals (Sweden)

    Sho Shinohara


    Full Text Available Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA, composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules.

  9. Electron elastic scattering off $A$@C$_{60}$: The role of atomic polarization under confinement

    CERN Document Server

    Dolmatov, V K; Chernysheva, L V


    The present paper explores possible features of electron elastic scattering off endohedral fullerenes $A$@C$_{60}$. It focuses on how dynamical polarization of the encapsulated atom $A$ by an incident electron might alter scattering off $A$@C$_{60}$ compared to the static-atom-$A$ case, as well as how the C$_{60}$ confinement modifies the impact of atomic polarization on electron scattering compared to the free-atom case. The aim is to provide researchers with a "relative frame of reference" for understanding which part of the scattering processes could be due to electron scattering off the encapsulated atom and which due to scattering off the C$_{60}$ cage. To meet the goal, the C$_{60}$ cage is modeled by an attractive spherical potential of a certain inner radius, thickness, and depth which is a model used frequently in a great variety of fullerene studies to date. Then, the Dyson equation for the self-energy part of the Green's function of an incident electron moving in the combined field of an encapsulat...

  10. Confinement and correlation effects in the Xe@C60 generalized oscillator strengths

    CERN Document Server

    Amusia, M Ya; Dolmatov, V K


    The impact of both confinement and electron correlation on generalized oscillator strengths (GOS's) of endohedral atoms, A@C60, is theoretically studied choosing the Xe@C60 4d, 5s, and 5p fast electron impact ionization as the case study. Calculations are performed in the transferred to the atom energy region beyond the 4d threshold, omega = 75--175 eV. The calculation methodology combines the plane wave Born approximation, Hartree-Fock approximation, and random phase approximation with exchange in the presence of the C60 confinement. The confinement is modeled by a spherical delta-function-like potential as well as by a square well potential to evaluate the effect of the finite thickness of the C60 cage on the Xe@C60 GOS's. Dramatic distortion of the 4d, 5p, and 5s GOS's by the confinement is demonstrated, compared to the free atom. Considerable contributions of multipolar transitions beyond dipole transitions in the calculated GOS's is revealed, in some instances. The vitality of accounting for electron cor...

  11. First Production of C60 Nanoparticle Plasma Jet for Study of Disruption Mitigation for ITER (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.; Brockington, S.; Case, A.; Messer, S. J.; Witherspoon, F. D.


    Unique fast response and large mass-velocity delivery of nanoparticle plasma jets (NPPJs) provide a novel application for ITER disruption mitigation, runaway electrons diagnostics and deep fueling. NPPJs carry a much larger mass than usual gases. An electromagnetic plasma gun provides a very high injection velocity (many km/s). NPPJ has much higher ram pressure than any standard gas injection method and penetrates the tokamak confining magnetic field. Assimilation is enhanced due to the NP large surface-to-volume ratio. Radially expanding NPPJs help achieving toroidal uniformity of radiation power. FAR-TECH's NPPJ system was successfully tested: a coaxial plasma gun prototype (˜35 cm length, 96 kJ energy) using a solid state TiH2/C60 pulsed power cartridge injector produced a hyper-velocity (>4 km/s), high-density (>10^23 m-3), C60 plasma jet in ˜0.5 ms, with ˜1-2 ms overall response-delivery time. We present the TiH2/C60 cartridge injector output characterization (˜180 mg of sublimated C60 gas) and first production results of a high momentum C60 plasma jet (˜0.6

  12. Self-Cleaning Photocatalytic Polyurethane Coatings Containing Modified C60 Fullerene Additives

    Directory of Open Access Journals (Sweden)

    Jeffrey G. Lundin


    Full Text Available Surfaces are often coated with paint for improved aesthetics and protection; however, additional functionalities that impart continuous self-decontaminating and self-cleaning properties would be extremely advantageous. In this report, photochemical additives based on C60 fullerene were incorporated into polyurethane coatings to investigate their coating compatibility and ability to impart chemical decontaminating capability to the coating surface. C60 exhibits unique photophysical properties, including the capability to generate singlet oxygen upon exposure to visible light; however, C60 fullerene exhibits poor solubility in solvents commonly employed in coating applications. A modified C60 containing a hydrophilic moiety was synthesized to improve polyurethane compatibility and facilitate segregation to the polymer–air interface. Bulk properties of the polyurethane films were analyzed to investigate additive–coating compatibility. Coatings containing photoactive additives were subjected to self-decontamination challenges against representative chemical contaminants and the effects of additive loading concentration, light exposure, and time on chemical decontamination are reported. Covalent attachment of an ethylene glycol tail to C60 improved its solubility and dispersion in a hydrophobic polyurethane matrix. Decomposition products resulting from oxidation were observed in addition to a direct correlation between additive loading concentration and decomposition of surface-residing contaminants. The degradation pathways deduced from contaminant challenge byproduct analyses are detailed.

  13. Molecular mechanics on bonding and non-bonding interactions in (atom@C60)

    Institute of Scientific and Technical Information of China (English)

    朱传宝; 徐志谨; 严继民


    The interactions between the embedded atom X (X=Li,Na,K,Rb,Cs; F,Cl,Br,I) and C60cage in the endohedral-form complexes (X@C60) are calculated and discussed according to molecular mechanics from the point of view of the bonding and non-bonding.It is found from the computational results that for atoms with radii larger than Li’s,their locations with the minimum interaction in (X@C60) are at the cage center,while atom Li has an off-center location with the minimum interaction deviation of-0.05 nm,and the cage-environment in C60 can be regarded as sphero-symmetry in the region with radius r of ~0.2 nm.It is shown that the interaction between X and C60 cage is of non-bonding characteristic,and this non-bonding interaction is not purely electrostatic.The repulsion and dispersion in non-bonding interactions should not be neglected,which make important contribution to the location with minimum interaction of X,at center or off center.Some rules about the variations of interactions with atomic radii have been ob

  14. The interaction of C60 on Si(111 7x7 studied by Supersonic Molecular Beams: interplay between precursor kinetic energy and substrate temperature in surface activated processes.

    Directory of Open Access Journals (Sweden)

    Lucrezia eAversa


    Full Text Available Buckminsterfullerene (C60 is a molecule fully formed of carbon that can be used, owing to its electronic and mechanical properties, as clean precursor for the growth of carbon-based materials, ranging from -conjugated systems (graphenes to synthesized species, e.g. carbides such as silicon carbide (SiC. To this goal, C60 cage rupture is the main physical process that triggers material growth. Cage breaking can be obtained either thermally by heating up the substrate to high temperatures (630°C, after C60 physisorption, or kinetically by using Supersonic Molecular Beam Epitaxy (SuMBE techniques. In this work, aiming at demonstrating the growth of SiC thin films by C60 supersonic beams, we present the experimental investigation of C60 impacts on Si(111 7x7 kept at 500°C for translational kinetic energies ranging from 18 to 30 eV. The attained kinetically activated synthesis of SiC submonolayer films is probed by in-situ surface electron spectroscopies (XPS and UPS. Furthermore, in these experimental conditions the C60-Si(111 7×7 collision has been studied by computer simulations based on a tight-binding approximation to Density Functional Theory, DFT. Our theoretical and experimental findings point towards a kinetically driven growth of SiC on Si, where C60 precursor kinetic energy plays a crucial role, while temperature is relevant only after cage rupture to enhance Si and carbon reactivity. In particular, we observe a counterintuitive effect in which for low kinetic energy (below 22 eV, C60 bounces back without breaking more effectively at high temperature due to energy transfer from excited phonons. At higher kinetic energy (22 < K < 30 eV, for which cage rupture occurs, temperature enhances reactivity without playing a major role in the cage break. These results are in good agreement with ab-initio molecular dynamics simulations. SuMBE is thus a technique able to drive materials growth at low temperature regime.

  15. Theoretical Studies on Electronic States of Rh-C60. Possibility of a Room-temperature Organic Ferromagnet

    Directory of Open Access Journals (Sweden)

    K. Yamaguchi


    Full Text Available A possible mechanism for a ferromagnetic interaction in the rhombic (Rh formof C60 (Rh-C60 is suggested on the basis of theoretical studies in relation to cage distortionof the C60 unit in the polymerized 2D-plane. Band structure calculations on Rh-C60 showthat cage distortion leads to competition between diamagnetic and ferromagnetic states,which give rise to the possibility of thermally populating the ferromagnetic state.

  16. Linear pi-conjugated systems derivatized with C60-fullerene as molecular heterojunctions for organic photovoltaics. (United States)

    Roncali, Jean


    This tutorial review covers recent contributions in the area of linear pi-conjugated systems bound to fullerenes in view of their application as active materials in photovoltaic devices. The first part discusses the concepts of double-cable polymer and molecular hetero-junction and presents several examples of chemically or electrochemically synthesized C60-derivatized conjugated polymers. The second and main part of the article concerns the various classes of C60-derivatized pi-conjugated oligomers designed in view of their utilization in single-component photovoltaic devices. Thus, C60-containing pi-conjugated systems such as oligoarylenevinylenes, oligoaryleneethynylenes and oligothiophenes are discussed on the basis of the relationships between molecular structure, photophysical properties and performances of the derived photovoltaic devices. A brief last section presents some recent examples of surface-attached molecular hetero-junctions based on self-assembled monolayers and discusses possible routes for future research.

  17. Broad spectral sensitization of organic photovoltaic heterojunction device by perylene and C60 (United States)

    Feng, W.; Fujii, A.; Lee, S.; Wu, H.; Yoshino, K.


    The characteristics of heterojunction devices consisting of indium-tin-oxide (ITO)/poly(3-alkylthiophene) (PAT)/N,N'-diphenyl glyoxaline-3, 4, 9, 10-perylene tetracarboxylic acid diacidamide (PV)/Al, ITO/PAT-PV/PV/Al, and ITO/PAT-PV-C60/PV/Al, which are typical photoinduced rectifiers, are reported. The device under dark conditions is almost insulating; however, when exposed to light marked rectification and strong photoresponse over a broad spectral range covering near-infrared to visible and UV wavelengths are observed. The effect of PV and C60 doping as well as annealing on spectral photoresponse and photoelectric conversion was investigated. The results show that the efficient photoinduced electron transfer from PAT to PV and C60 occurs at the interface between the composite and junction.

  18. Performance improvement in pentacene organic thin film transistors by inserting a C60 ultrathin layer

    Institute of Scientific and Technical Information of China (English)

    Sun Qin-Jun; Xu Zheng; Zhao Su-Ling; Zhang Fu-Jun; Gao Li-Yan


    The contact effect on the performances of organic thin film transistors is studied here. A C60 ultrathin layer is inserted between Al source-drain electrode and pentacene to reduce the contact resistance. By a 3 nm C60 modification,the injection harrier is lowered and the contact resistance is reduced. Thus, the field-effect mobility increases from 0.12to 0.52 cm2/(V.s). It means that inserting a C60 ultra thin layer is a good method to improve the organic thin film transistor (OTFT) performance. The output curve is simulated by using a charge drift model. Considering the contact of OTFTs should be carried out.

  19. Valence photoelectron spectra of an electron-beam-irradiated C60 film (United States)

    Onoe, Jun; Nakao, Aiko; Hida, Akira


    Valence photoelectron spectra of an electron-beam (EB) irradiated C60 film, which exhibited metallic electron-transport properties in air at room temperature, are presented. The electronic structure of the C60 film became closer to that of graphite as the EB-irradiation time increased, and its density of states around the Fermi level was eventually greater than for the graphite. This suggests that the electronic structure of the C60 film changed from a semiconductor to a semimetal and/or metal by EB irradiation. Interestingly, the electronic structure remained metallic even after five days of air exposure, which is the reason for the metallic electron-transport property in our previous report [Appl. Phys. Lett. 82, 595 (2003)].

  20. Synthesis of N-acetamide C60 nitride and its performance of optical limiting

    Institute of Scientific and Technical Information of China (English)


    N-acetamide C60 nitride (N-acetamide-1,2-dihydro-1,2-aza-fullerene[60]) has been synthesized by the reaction of C60 and azidoacetamide and initially characterized. Its mechanism was that the objective product is formed through intermediate triazoline. The computational study shows that N-nitride structure is thermodynamically more stable by using the semi-empirical AM1 SCF-MO method. The properties of optical limiting were tested by using double frequency Nd∶YAG pulse laser system and showed that the optical limiting mechanism is reverse saturation absorption. A wavelength of 532 nm, compared with optical limiting for ns pulse, this new material has good optical limiting character for ps pulse. At wavelength of 707 nm, the capacity of optical limiting of the derivative is prior to C60.

  1. Mass spectrometric identification of C60 fragmentation regimes under energetic Cs+ bombardment

    CERN Document Server

    Zeeshan, Sumaira; Ahmad, Shoaib


    Three C60 fragmentation regimes in fullerite bombarded by Cs+ are identified as a function of its energy. C2 is the major species sputtered at all energies. For E(Cs+) < 1 keV C2 emissions dominate. C2 and C1 have highest intensities between 1 and 3 keV with increasing contributions from C3 and C4. Intensities of all fragments maximize around 2 keV. Above 3 keV, fragments densities stabilize. The roles of and the contributions from direct recoils and collision cascades are determined. Maximum direct recoil energy delivered to the C60 fullerite cage is 210 eV at which only C2 emissions occur is identified and an explanation provided. The three fragmentation regimes under continued Cs+ bombardment eventually lead to complete destruction of the C60 cages transforming fullerite into amorphous carbon

  2. Nonequilibrium electron-vibration coupling and conductance fluctuations in a C-60 junction

    DEFF Research Database (Denmark)

    Ulstrup, Soren; Frederiksen, Thomas; Brandbyge, Mads


    We investigate chemical bond formation and conductance in a molecular C-60 junction under finite bias voltage using first-principles calculations based on density functional theory and nonequilibrium Green's functions (DFT-NEGF). At the point of contact formation we identify a remarkably strong...... coupling between the C-60 motion and the molecular electronic structure. This is only seen for positive sample bias, although the conductance itself is not strongly polarity dependent. The nonequilibrium effect is traced back to a sudden shift in the position of the voltage drop with a small C-60...... displacement. Combined with a vibrational heating mechanism we construct a model from our results that explain the polarity-dependent two-level conductance fluctuations observed in recent scanning tunneling microscopy (STM) experiments [N. Neel et al., Nano Lett. 11, 3593 (2011)]. These findings highlight...

  3. Quantum and classical features of the photoionization spectrum of C$_{60}$

    CERN Document Server

    Verkhovtsev, Alexey V; Solov'yov, Andrey V


    Considering the photoionization process of the C$_{60}$ fullerene, we elucidate the contributions of various classical and quantum physics phenomena manifesting themselves in this process. Comparing the results, based on the {\\it ab initio} and model approaches, we map the well-resolved features of the photoionization spectrum to single-particle and collective excitations having the different physical nature. We demonstrate that the peculiarities arising in the photoionization spectrum of C$_{60}$ atop the dominating plasmon excitations have the quantum origin. In particular, we demonstrate that a series of individual peaks can be assigned to the optically allowed discrete transitions, ionization of particular molecular orbitals of the system, or to the single-electron transitions to the continuum. The analysis performed gives a detailed information on the nature of numerous features in the photoionization spectrum of C$_{60}$.

  4. Self-healing phenomenon and dynamic hardness of C60-based nanocomposite coatings. (United States)

    Penkov, Oleksiy V; Pukha, Volodymyr E; Devizenko, Alexander Yu; Kim, Hae-Jin; Kim, Dae-Eun


    The phenomenon of surface self-healing in C60-based polymer coatings deposited by ion-beam assisted physical vapor deposition was investigated. Nanoindentation of the coatings led to the formation of a protrusion rather than an indent. This protrusion was accompanied by an abnormal shape of the force-distance curve, where the unloading curve lies above the loading curve due to an additional force applied in pulling the indenter out of the media. The coatings exhibited a nanocomposite structure that was strongly affected by the ratio of C60 ion and C60 molecular beam intensities during deposition. The coatings also demonstrated the dynamic hardness effect, where the effective value of the hardness depends significantly on the indentation speed.

  5. SEMICONDUCTOR DEVICES: CuPc/C60 heterojunction thin film optoelectronic devices (United States)

    Murtaza, Imran; Qazi, Ibrahim; Karimov, Khasan S.


    The optoelectronic properties of heterojunction thin film devices with ITO/CuPc/C60/Al structure have been investigated by analyzing their current-voltage characteristics, optical absorption and photocurrent. In this organic photovoltaic device, CuPc acts as an optically active layer, C60 as an electron-transporting layer and ITO and Al as electrodes. It is observed that, under illumination, excitons are formed, which subsequently drift towards the interface with C60, where an internal electric field is present. The excitons that reach the interface are subsequently dissociated into free charge carriers due to the electric field present at the interface. The experimental results show that in this device the total current density is a function of injected carriers at the electrode-organic semiconductor surface, the leakage current through the organic layer and collected photogenerated current that results from the effective dissociation of excitons.

  6. The effect of gate voltage on the electrical transport properties in the contacts of C60 to carbon nanotube leads

    Directory of Open Access Journals (Sweden)

    AA Shokri


    Full Text Available  In this paper, we examined the effect of gate voltage, bias voltage, contact geometries and the different bond lengths on the electrical transport properties in a nanostructure consisting of C60 molecule attached to two semi-infinite leads made of single wall carbon nanotubes in the coherent regime. Our calculation was based on the Green’s function method within nearest-neighbour tight-binding approximation. After the calculation was of transmission, the electrical current was obtained by the Landauer-Buttiker formula. Next, the effect of the mentioned factors was investigated in the nanostructure. The application of the present results may be useful in designing devices based on molecular electronics in nanoscale.

  7. Magnetic field effect spectroscopy of C60-based films and devices (United States)

    Gautam, Bhoj R.; Nguyen, Tho D.; Ehrenfreund, Eitan; Vardeny, Z. Valy


    We performed spectroscopy of the magnetic field effect (MFE) including magneto-photoinduced absorption (MPA) and magneto-photoluminescence (MPL) at steady state conditions in annealed and pristine fullerene C60 thin films, as well as magneto-conductance (MC) in organic diodes based on C60 interlayer. The hyperfine interaction has been shown to be the primary spin mixing mechanism for the MFE in the organics. In this respect, C60 is a unique material because 98.9% of the carbon atoms are 12C isotope, having spinless nucleus and thus lack hyperfine interaction. In spite of this, we obtained substantial MPA (up to ˜15%) and significant MC and MPL in C60 films and devices, and thus mechanisms other than the hyperfine interaction are responsible for the MFE in this material. Specifically, we found that the MFE(B) response is composed of narrow (˜10 mT) and broad (>100 mT) components. The narrow MFE(B) component is due to spin-dependent triplet exciton recombination in C60, which dominates the MPA(B) response at low pump intensities in films, or the MC response at small current densities in devices. In contrast, the broad MFE(B) component dominates the MPA(B) response at high pump intensities (or large current densities for MC(B)) and is attributed to spin mixing in the polaron pairs spin manifold due to g-factor mismatch between the electron- and hole-polarons in C60. Our results show that the organic MFE has a much broader scope than believed before.

  8. Active Oxygen Radical Scavenging Ability of Water-Soluble β-Alanine C60 Adducts

    Institute of Scientific and Technical Information of China (English)


    Water-soluble β-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2-and hydroxyl radicalOH were studied by autoxidation ofpyrogallol and chemiluminescence, respectively. It was found that β-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.

  9. Single-crystalline C60 nanostructures by sonophysical preparation: tuning hollow nanobowls as catalyst supports for methanol oxidation. (United States)

    Zhang, Yang; Jiang, Lang; Li, Hui; Fan, Louzhen; Hu, Wenping; Wang, Chunru; Li, Yongfang; Yang, Shihe


    Large-scale single-crystalline hollow nanobowls of pure C(60) were prepared by applying a sonophysical strategy in a binary organic solution. Through the simple adjustment of the concentration of the C(60) /m-xylene solution and the volume ratio of m-xylene to acetonitrile, C(60) nanorings, nanoplates, nanorods, and nanowires were also selectively synthesized. The promise of the C(60) hollow structures as Pt catalyst supports is heightened by the significantly enhanced catalytic activity toward methanol oxidation for a given amount of C(60) used, which demonstrates their potential application in fuel cells.

  10. Optical conductivity in A3C60 (A=K, Rb)

    NARCIS (Netherlands)

    Brink, J. van den; Gunnarsson, O.; Eyert, V.


    Published in: Phys. Rev. B 57 (1998) 2163-2167 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We study the optical conductivity in A3C60 (A =K, Rb). The effects of the electron-phonon interaction is included to lowest order in the coupling strength lambda. It is

  11. Excitons in C-60 studied by temperature-dependent optical second-harmonic generation

    NARCIS (Netherlands)

    Janner, A.M; Eder, R; Koopmans, B; Jonkman, H.T.; Sawatzky, G.A


    The electric-dipole-forbidden T-1(1g) excitonic state of solid C-60 at hw=1.81 eV can be probed with a second-harmonic generation (SHG) experiment. We show that the SHG line shape depends strongly on the degree of rotational order. We observe a splitting into two peaks below the rotational ordering

  12. Conformational, IR spectroscopic and electronic properties of conium alkaloids and their adducts with C60 fullerene (United States)

    Zabolotnyi, M. A.; Prylutskyy, Yu I.; Poluyan, N. A.; Evstigneev, M. P.; Dovbeshko, G. I.


    Conformational, IR spectroscopic and electronic properties of the components of Conium alkaloids (Conium maculatum) in aqueous environment were determined by model calculations and experiment. With the help of FT-IR spectroscopy the possibility of formation of an adduct between γ-coniceine alkaloid and C60 fullerene was demonstrated, which is important for further application of conium analogues in biomedical purposes.

  13. Growth of α-sexithiophene nanostructures on C60 thin film layers

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Madsen, Morten; Balzer, Frank


    Organic molecular beam grown -sexithiophene (-6T) forms nanostructured thin films on buckminsterfullerene (C60) thin film layers. At substrate temperatures of 300K during growth a rough continuous film is observed, which develop to larger elongated islands and dendritic- as well as needle like...

  14. Uncovering a solvent-controlled preferential growth of buckminsterfullerene (C60) nanowires

    DEFF Research Database (Denmark)

    Geng, Junfeng; Solov'yov, Ilia; Zhou, Wuzong


    The fullerene (C_60) nanowires, which possess a highly unusual morphology featured by a prismlike central core and three nanobelt-like wings joined along the growth direction to give an overall Y-shaped cross section, were studied. The experimental observation coupled with theoretical calculation...

  15. Ab-initio modeling of an anion $C_{60}^-$ pseudopotential for fullerene-based compounds

    CERN Document Server

    Vrubel, I I; Ivanov, V K


    A pseudopotential of $C_{60}^-$ has been constructed from ab-initio quantum-mechanical calculations. Since the obtained pseudopotential can be easily fitted by rather simple analytical approximation it can be effectively used both in classical and quantum molecular dynamics of fullerene-based compounds.

  16. Analytical study of PPV-oligomer- and C60-based devices for optimising organic solar cells

    NARCIS (Netherlands)

    Geens, Wim; Poortmans, Jef; Jain, Suresh C.; Nijs, Johan; Mertens, Robert; Veenstra, Sjoerd C.; Krasnikov, Viktor V.; Hadziioannou, Georges


    A blend of a 5-ring n-octyloxy-substituted oligo(p-phenylene vinylene) and C60, sandwiched between two electrodes, has been used as the active layer for an organic solar cell. It delivered external quantum efficiencies up to 60% in the visible and 70% in the UV part of the spectrum. To unambiguously

  17. Dynamics of the artificially created vacancies in the monomolecular C60 layers (United States)

    Olyanich, D. A.; Utas, T. V.; Zotov, A. V.; Saranin, A. A.


    Dynamics of single and double vacancies within the monomolecular C60 layer on the In-modified Au/Si(111) √{ 3} ×√{ 3} surface have been studied by means of variable temperature scanning tunneling microscopy (STM). The vacancies were deliberately created in the layer using STM tip impact in the regimes below decomposition threshold. Single vacancy motion has been found to be a thermally activated process characterized by the activation energy of 1.5 ± 0.3 eV. This is an effective activation energy which agrees with the net value consisted of the term responsible for vacancy migration within the free-standing C60 layer, 0.88 eV and that for individual C60 migration on (Au, In)/Si(111) surface, 0.4 eV. Mobility of C60 vacancies has been found to be affected by In adatoms. It can be slowed down by more than an order of magnitude by deposition of only 0.2 monolayer of additional In. The double vacancies have been found to be more mobile than single vacancies in which its effect is provided by a specific rotational mechanism of their motion.

  18. Analytical study of PPV-oligomer- and C-60-based devices for optimising organic solar cells

    NARCIS (Netherlands)

    Geens, W.; Poortmans, J.; Jain, S.C.; Nijs, J.; Mertens, R.; Veenstra, S.C.; Krasnikov, V.V.; Hadziioannou, G


    A blend of a 5-ring n-octyloxy-substituted oligo(p-phenylene vinylene) and C60, sandwiched between two electrodes, has been used as the active layer for an organic solar cell. It delivered external quantum efficiencies up to 60% in the visible and 70% in the UV part of the spectrum. To unambiguously

  19. Efficient Energy Sensitization of C 60 and Application to Organic Photovoltaics

    KAUST Repository

    Trinh, Cong


    Fullerenes are currently the most popular electron-acceptor material used in organic photovoltaics (OPVs) due to their superior properties, such as good electron conductivity and efficient charge separation at the donor/acceptor interface. However, low absorptivity in the visible spectral region is a significant drawback of fullerenes. In this study, we have designed a zinc chlorodipyrrin derivative (ZCl) that absorbs strongly in the visible region (450-600 nm) with an optical density 7-fold higher than a C60 film. ZCl efficiently transfers absorbed photoenergy to C60 in mixed films. Application of ZCl as an energy sensitizer in OPV devices leads to an increase in the photocurrent from the acceptor layer, without changing the other device characteristics, i.e., open circuit voltage and fill factor. For example, C 60-based OPVs with and without the sensitizer give 4.03 and 3.05 mA/cm2, respectively, while both have VOC = 0.88 V and FF = 0.44. Our ZCl sensitization approach improves the absorbance of the electron-acceptor layer while still utilizing the beneficial characteristics of C60 in OPVs. © 2013 American Chemical Society.

  20. Highly-charged-ion-induced electron emission from C-60 thin films

    NARCIS (Netherlands)

    Bodewits, E.; Hoekstra, R.; Kowarik, G.; Dobes, K.; Aumayr, F.


    The secondary electron yields as a result of highly charged ions impinging on clean Au(111) and thin films of C-60 on Au have been measured. This has been done for film thicknesses of one to five monolayers and several charge states of Ar and Xe ions. For all ions an increase of 35% in the secondary

  1. UV/Vis spectroscopy of C60 embedded in water ice

    DEFF Research Database (Denmark)

    Cuylle, Steven; Linnartz, Harold; Thrower, John


    Electronic solid state spectra are recorded for C60 embedded in 40 K water ice using broad band direct absorption spectroscopy, and assigned with reference to existing matrix data. The results are interesting in view of the recent gas phase detection of fullerenes in the interstellar medium...

  2. A Microscopic Model for the Second-Harmonic Generation from C60

    NARCIS (Netherlands)

    Koopmans, Bert; Janner, Anna-Maria; Guardini, Roberta; Jonkman, Harry T.; Sawatzky, George A.; Woude, Folkert van der


    We discuss the microscopic origin of the Second-Harmonic Generation (SHG) resonance at ħω=1.81 eV, based on spectroscopic and thickness dependent SHG measurements on C60 thin films. We assign the three-level diagram responsible for the observed SHG resonance, and show it to be of magnetic-dipole-ind


    NARCIS (Netherlands)



    We discuss the microscopic origin of the Second-Harmonic Generation (SHG) resonance at hBAR omega=1.81 eV, based on spectroscopic and thickness dependent SHG measurements on C-60 thin films. We assign the three-level diagram responsible for the observed SHG resonance, and show it to be of magnetic-d

  4. Cu掺杂TiO2作为SERS基底的研究%Study of enhanced Raman scattering for molecules adsorbed on Cu-doped TiO2 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    薛向欣; 纪伟; 毛竹; 阮伟东; 赵冰; MA Stephen; LOMBARDI John R


    本文采用溶胶-水热法制备了TiO2及Cu掺杂的TiO2纳米粒子作为表面增强拉曼光谱(SERS)活性基底,观察到当4-巯基苯甲酸吸附在3%Cu掺杂的TiO2表面上时,其SERS信号得到了最大程度的增强.Cu离子掺杂进TiO2晶格时会使TiO2表面的缺陷浓度(表面态)得到增加,一定量的缺陷浓度对TiO2-to-Molecule的电荷转移机理起到促进作用,进一步证明了化学增强机理在SERS现象的贡献.%A series of Cu-doped TiO2 (Cu-TiO2) nanoparticles (NPs) have been synthesized for the application as surface-enhanced Raman scattering (SERS) substrates.Significant SERS signals were observed when the probing molecules of 4-mercaptobenzoic acid were adsorbed on the surface of these substrates.Transmission electron microscopy (TEM), UV-vis spectrophotometer, X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been employed to investigate the TiO2 and Cu-TiO2 nanaoparticles.The crystalline defects of the Cu-TiO2 NPs caused by Cu dopants affected the SERS activity.In these defect areas, the electrons transfer from the valance band of TiO2 NPs and then transfers to the surface state energy levels.The inner-particle charge-transfers also contributed to the particle-to-molecule charge-transfers, which played a very important role in the enhancements of SERS signals.

  5. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads


    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  6. X-ray observation of a helium atom and placing a nitrogen atom inside He@C60 and He@C70. (United States)

    Morinaka, Yuta; Sato, Satoru; Wakamiya, Atsushi; Nikawa, Hidefumi; Mizorogi, Naomi; Tanabe, Fumiyuki; Murata, Michihisa; Komatsu, Koichi; Furukawa, Ko; Kato, Tatsuhisa; Nagase, Shigeru; Akasaka, Takeshi; Murata, Yasujiro


    Single crystal X-ray analysis has been used as a powerful method to determine the structure of molecules. However, crystallographic data containing helium has not been reported, owing to the difficulty in embedding helium into crystalline materials. Here we report the X-ray diffraction study of He@C60 and the clear observation of a single helium atom inside C60. In addition, the close packing of a helium atom and a nitrogen atom inside fullerenes is realized using two stepwise insertion techniques, that is, molecular surgery to synthesize the fullerenes encapsulating a helium atom, followed by nitrogen radio-frequency plasma methods to generate the fullerenes encapsulating both helium and nitrogen atoms. Electron spin resonance analysis reveals that the encapsulated helium atom has a small but detectable influence on the electronic properties of the highly reactive nitrogen atom coexisting inside the fullerene, suggesting the potential usage of helium for controlling electronic properties of reactive species.

  7. Adsorbed Water Illustration (United States)


    The Thermal and Electrical Conductivity Probe on NASA's Phoenix Mars Lander detected small and variable amounts of water in the Martian soil. In this schematic illustration, water molecules are represented in red and white; soil minerals are represented in green and blue. The water, neither liquid, vapor, nor solid, adheres in very thin films of molecules to the surfaces of soil minerals. The left half illustrates an interpretation of less water being adsorbed onto the soil-particle surface during a period when the tilt, or obliquity, of Mars' rotation axis is small, as it is in the present. The right half illustrates a thicker film of water during a time when the obliquity is greater, as it is during cycles on time scales of hundreds of thousands of years. As the humidity of the atmosphere increases, more water accumulates on mineral surfaces. Thicker films behave increasingly like liquid water. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Temperature-dependent nucleation and capture-zone scaling of C 60 on silicon oxide (United States)

    Groce, M. A.; Conrad, B. R.; Cullen, W. G.; Pimpinelli, A.; Williams, E. D.; Einstein, T. L.


    Submonolayer films of C 60 have been deposited on ultrathin SiO 2 films for the purpose of characterizing the initial stages of nucleation and growth as a function of temperature. Capture zones extracted from the initial film morphology were analyzed using both the gamma and generalized Wigner distributions. The calculated critical nucleus size i of the C 60 islands was observed to change over the temperature range 298 K to 483 K. All fitted values of i were found to be between 0 and 1, representing stable monomers and stable dimers, respectively. With increasing temperature of film preparation, we observed i first increasing through this range and then decreasing. We discuss possible explanations of this reentrant-like behavior.

  9. Recent Advances in Electrochemical Biosensors Based on Fullerene-C60 Nano-Structured Platforms. (United States)

    Pilehvar, Sanaz; De Wael, Karolien


    Nanotechnology is becoming increasingly important in the field of (bio)sensors. The performance and sensitivity of biosensors is greatly improved with the integration of nanomaterials into their construction. Since its first discovery, fullerene-C60 has been the object of extensive research. Its unique and favorable characteristics of easy chemical modification, conductivity, and electrochemical properties has led to its tremendous use in (bio)sensor applications. This paper provides a concise review of advances in fullerene-C60 research and its use as a nanomaterial for the development of biosensors. We examine the research work reported in the literature on the synthesis, functionalization, approaches to nanostructuring electrodes with fullerene, and outline some of the exciting applications in the field of (bio)sensing.

  10. Electronic communication in tetrathiafulvalene (TTF)/C60 systems: toward molecular solar energy conversion materials? (United States)

    Martín, Nazario; Sánchez, Luis; Herranz, María Angeles; Illescas, Beatriz; Guldi, Dirk M


    The covalent connection of the electron acceptor C 60 to p-quinonoid pi-extended tetrathiafulvalenes (exTTFs) has allowed for the preparation of new photo- and electroactive conjugates able to act as artificial photosynthetic systems and active molecular materials in organic photovoltaics. The gain of aromaticity undergone by the pi-extended TTF unit in the oxidation process results in highly stabilized radical ion pairs, namely, C 60 (*-)/exTTF (*+). Lifetimes for such charge-separated states, ranging from a few nanoseconds to hundreds of microseconds, have been achieved by rationally modifying the nature of the chemical spacers. These long-lived radical pairs are called to play an important role for the conversion of sunlight into chemical or electrical power.

  11. Synthesis of a novel perylene diimide derivative and its charge transfer interaction with C60

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; SHI MinMin; YANG LiGong; CHEN HongZheng; WANG Mang


    A novel organic electron accepter, N,N'-dipyrimidinyl-3,4,9,10-perylene-tetracarboxylic diimide (DMP), was designed and synthesized.The molecular structure was characterized by FTIR spectrum and ele-mental analysis.By cyclic voltammetry measurements, DMP was found to possess a lower LUMO en-ergy level than N,N'-diphenyl-3,4,9,10-perylene-tetracarboxylic diimide due to the stronger elec-tron-withdrawing pyrimidinyl group than the phenyl group.Fluorescence quenching is observed in a dual-layer film consisting of a DMP layer and a C60 layer and was attributed to the charge transfer at the interface due to the energy level offset between DMP and C60.

  12. Unravelling the multilayer growth of the fullerene C60 in real time (United States)

    Bommel, S.; Kleppmann, N.; Weber, C.; Spranger, H.; Schäfer, P.; Novak, J.; Roth, S.V.; Schreiber, F.; Klapp, S.H.L.; Kowarik, S.


    Molecular semiconductors are increasingly used in devices, but understanding of elementary nanoscopic processes in molecular film growth is in its infancy. Here we use real-time in situ specular and diffuse X-ray scattering in combination with kinetic Monte Carlo simulations to study C60 nucleation and multilayer growth. We determine a self-consistent set of energy parameters describing both intra- and interlayer diffusion processes in C60 growth. This approach yields an effective Ehrlich–Schwoebel barrier of EES=110 meV, diffusion barrier of ED=540 meV and binding energy of EB=130 meV. Analysing the particle-resolved dynamics, we find that the lateral diffusion is similar to colloids, but characterized by an atom-like Schwoebel barrier. Our results contribute to a fundamental understanding of molecular growth processes in a system, which forms an important intermediate case between atoms and colloids. PMID:25369851

  13. First-principles calculations of the electronic structure of one-dimensional C60 polymers (United States)

    Beu, Titus A.; Onoe, Jun; Hida, Akira


    The geometrical and electronic properties of two dimers (one with C2h symmetry) from the Stone-Wales rearrangement sequence of C60 dimers [described by E. Osawa and K. Honda, Full Sci. Technol. 4, 939 (1996)] are investigated by density functional and tight-binding calculations. The trimer and the infinite periodic polymer derived from the C2h symmetry dimer are shown to continue a decreasing trend of the energy gap between the highest occupied (HOMO) and the lowest unoccupied (LUMO) molecular orbitals to values smaller than 0.1 eV. The very small energy gap, in conjunction with the extension of the HOMO orbital over the whole cross-linkage region, provides an explanation for the observed conducting properties of electron beam irradiated C60 films.

  14. Novel facile method for obtaining CdSe/polyaniline/C60 composite materials (United States)

    Rusen, Edina; Diacon, Aurel; Mocanu, Alexandra; Nistor, Leona Cristina


    This study presents a novel method for the oxidative polymerization of aniline (ANI) by employing fullerene C60/cadmium selenide (CdSe) quantum dots, as promoting agent of the polymerization system. The polymerization initiation mechanism is based on the difference between the HOMO-LUMO energy levels of the components which permits the formation of a continuous donor-acceptor exchange. Both the polymerization reaction evolution and the molecular weights of the obtained polymers have been characterized. The novelty of the paper consists in the synthesis of a novel nano-composite material through a novel polymerization technique. The resulting material containing PANI, CdSe quantum dots and C60 has been characterized by UV-Vis, NIR, fluorescence, TEM and GPC analyses. PMID:27572228

  15. Novel facile method for obtaining CdSe/polyaniline/C60 composite materials. (United States)

    Rusen, Edina; Diacon, Aurel; Mocanu, Alexandra; Nistor, Leona Cristina


    This study presents a novel method for the oxidative polymerization of aniline (ANI) by employing fullerene C60/cadmium selenide (CdSe) quantum dots, as promoting agent of the polymerization system. The polymerization initiation mechanism is based on the difference between the HOMO-LUMO energy levels of the components which permits the formation of a continuous donor-acceptor exchange. Both the polymerization reaction evolution and the molecular weights of the obtained polymers have been characterized. The novelty of the paper consists in the synthesis of a novel nano-composite material through a novel polymerization technique. The resulting material containing PANI, CdSe quantum dots and C60 has been characterized by UV-Vis, NIR, fluorescence, TEM and GPC analyses.

  16. Recent Advances in Electrochemical Biosensors Based on Fullerene-C60 Nano-Structured Platforms

    Directory of Open Access Journals (Sweden)

    Sanaz Pilehvar


    Full Text Available Nanotechnology is becoming increasingly important in the field of (biosensors. The performance and sensitivity of biosensors is greatly improved with the integration of nanomaterials into their construction. Since its first discovery, fullerene-C60 has been the object of extensive research. Its unique and favorable characteristics of easy chemical modification, conductivity, and electrochemical properties has led to its tremendous use in (biosensor applications. This paper provides a concise review of advances in fullerene-C60 research and its use as a nanomaterial for the development of biosensors. We examine the research work reported in the literature on the synthesis, functionalization, approaches to nanostructuring electrodes with fullerene, and outline some of the exciting applications in the field of (biosensing.

  17. Optical modeling of organic solar cells based on CuPc and C60. (United States)

    Monestier, Florent; Simon, Jean-Jacques; Torchio, Philippe; Escoubas, Ludovic; Ratier, Bernard; Hojeij, Wassim; Lucas, Bruno; Moliton, André; Cathelinaud, Michel; Defranoux, Christophe; Flory, François


    We have investigated the influence of the poly(3,4-ethylenedioxythiophene)-blend-poly(styrene-sulfonate) (PEDOT:PSS) layer on the short-circuit current density (J(sc)) of single planar heterojunction organic solar cells based on a copper phthalocyanine (CuPc)-buckminsterfullerene (C(60)) active layer. Complete optical and electrical modeling of the cell has been performed taking into account optical interferences and exciton diffusion. Comparison of experimental and simulated external quantum efficiency has allowed us to estimate the exciton diffusion length to be 37 nm for the CuPc and 19 nm for the C(60). The dependence of short-circuit current densities versus the thickness of the PEDOT:PSS layer is analyzed and compared with experimental data. It is found that the variation in short-circuit current densities could be explained by optical interferences.

  18. Novel facile method for obtaining CdSe/polyaniline/C60 composite materials (United States)

    Rusen, Edina; Diacon, Aurel; Mocanu, Alexandra; Nistor, Leona Cristina


    This study presents a novel method for the oxidative polymerization of aniline (ANI) by employing fullerene C60/cadmium selenide (CdSe) quantum dots, as promoting agent of the polymerization system. The polymerization initiation mechanism is based on the difference between the HOMO-LUMO energy levels of the components which permits the formation of a continuous donor-acceptor exchange. Both the polymerization reaction evolution and the molecular weights of the obtained polymers have been characterized. The novelty of the paper consists in the synthesis of a novel nano-composite material through a novel polymerization technique. The resulting material containing PANI, CdSe quantum dots and C60 has been characterized by UV-Vis, NIR, fluorescence, TEM and GPC analyses.

  19. Ultrafast dynamics and fragmentation of C60 in intense laser pulses

    CERN Document Server

    Lin, Zheng-Zhe


    The radiation-induced fragmentation of the C60 fullerene was investigated by the tight-binding electron-ion dynamics simulations. In intense laser field, the breathing vibrational mode is much more strongly excited than the pentagonal-pinch mode. The fragmentation effect was found more remarkable at long wavelength lambda>800 nm rather than the resonant wavelengths due to the internal laser-induced dipole force, and the production ratio of C and C2 rapidly grows with increasing wavelength. By such fragmentation law, C atoms, C2 dimers or large Cn fragments could be selectively obtained by changing the laser wavelength. And the fragmentation of C60 by two laser pulses like the multi-step atomic photoionization was investigated.

  20. Synthesis and Characterization of Conducting Elastomers Based on Interpenetrated C60-Derived Polymer Networks (United States)


    terpolymers of ethane/propene and 5-vinylnorborn-2-ene (as EPDM ).21 In the latter case, incorporation of the rigid rod-like conducting polymers...electron oxidation of C60 and its analogous, forming the cationic radical intermediates of fullerenes which were stabilized under strong acidic conditions...PTMO chain-softening transition at 14 °C (22.5 J/g) were found to stabilize following the annealing treatment during the first cooling cycle from 200

  1. Obtaining and investigation of C60 semiconductor compounds with a view to create effective solar cells (United States)

    Elistratova, M. A.; Zakharova, I. B.; Romanov, N. M.


    Reproducible vacuum method of thin fullerene films production with Cd impurity on Si, glass and mica surfaces are developed. Thin composite films were obtained by Knudsen cell method. Initial studies of condensation and surface morphology of the films are investigated SEM methods. Optical spectroscopy was used to confirm the obtained results. Results showed the presence of an additional peak associated with the formation of C60-CdTe molecular complexes. SEM results confirm absence of phase separation.

  2. Nonequilibrium electron-vibration coupling and conductance fluctuations in a C60 junction (United States)

    Ulstrup, Søren; Frederiksen, Thomas; Brandbyge, Mads


    We investigate chemical bond formation and conductance in a molecular C60 junction under finite bias voltage using first-principles calculations based on density functional theory and nonequilibrium Green's functions (DFT-NEGF). At the point of contact formation we identify a remarkably strong coupling between the C60 motion and the molecular electronic structure. This is only seen for positive sample bias, although the conductance itself is not strongly polarity dependent. The nonequilibrium effect is traced back to a sudden shift in the position of the voltage drop with a small C60 displacement. Combined with a vibrational heating mechanism we construct a model from our results that explain the polarity-dependent two-level conductance fluctuations observed in recent scanning tunneling microscopy (STM) experiments [N. Néel , Nano Lett.NALEFD1530-698410.1021/nl201327c 11, 3593 (2011)]. These findings highlight the significance of nonequilibrium effects in chemical bond formation/breaking and in electron-vibration coupling in molecular electronics.

  3. Target Plate Material Influence on Fullerene-C60 Laser Desorption/Ionization Efficiency (United States)

    Zeegers, Guido P.; Günthardt, Barbara F.; Zenobi, Renato


    Systematic laser desorption/ionization (LDI) experiments of fullerene-C60 on a wide range of target plate materials were conducted to gain insight into the initial ion formation in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The positive and negative ion signal intensities of precursor, fragment, and cluster ions were monitored, varying both the laser fluence (0-3.53 Jcm-2) and the ion extraction delay time (0-950 ns). The resulting species-specific ion signal intensities are an indication for the ionization mechanisms that contribute to LDI and the time frames in which they operate, providing insight in the (MA)LDI primary ionization. An increasing electrical resistivity of the target plate material increases the fullerene-C60 precursor and fragment anion signal intensity. Inconel 625 and Ti90/Al6/V4, both highly electrically resistive, provide the highest anion signal intensities, exceeding the cation signal intensity by a factor ~1.4 for the latter. We present a mechanism based on transient electrical field strength reduction to explain this trend. Fullerene-C60 cluster anion formation is negligible, which could be due to the high extraction potential. Cluster cations, however, are readily formed, although for high laser fluences, the preferred channel is formation of precursor and fragment cations. Ion signal intensity depends greatly on the choice of substrate material, and careful substrate selection could, therefore, allow for more sensitive (MA)LDI measurements.

  4. Possible light-induced superconductivity in K3C60 at high temperature. (United States)

    Mitrano, M; Cantaluppi, A; Nicoletti, D; Kaiser, S; Perucchi, A; Lupi, S; Di Pietro, P; Pontiroli, D; Riccò, M; Clark, S R; Jaksch, D; Cavalleri, A


    The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects such as the optical enhancement of superconductivity. Nonlinear excitation of certain phonons in bilayer copper oxides was recently shown to induce superconducting-like optical properties at temperatures far greater than the superconducting transition temperature, Tc (refs 4-6). This effect was accompanied by the disruption of competing charge-density-wave correlations, which explained some but not all of the experimental results. Here we report a similar phenomenon in a very different compound, K3C60. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. These same signatures are observed at equilibrium when cooling metallic K3C60 below Tc (20 kelvin). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this as a possible explanation of our results.

  5. Biodistribution of fullerene derivative C60(OH)x(O)y

    Institute of Scientific and Technical Information of China (English)


    The biological behavior of fullerene derivatives shows their considerable potential application in medicine field. To understand the biodistribution of C60 derivatives as drugs or drug carriers, a simple water-soluble derivative C60(OH)x(O)y was labeled with 99mTc. A y-counter and a sin gle photo emission computed tomography (SPECT) were used to assess the biodistribution and metabolism of the la beled compound in mice and rabbits, respectively. The re sults showed that the compound could be absorbed rapidly by tissues, especially by coronal bone, breastbone, backbone,extremity honeycomb, liver and spleen. The clearance was slow from all tissues except for brain. The compound might be excreted through urine and enteron. The biodistribution shows some difference from that of Yamago et al. In this note,we discuss the possible reason leading to the difference. Fur ther study is needed to find out to what extent the C60 itself determines the biodistribution of derivatives.

  6. Target Plate Material Influence on Fullerene-C60 Laser Desorption/Ionization Efficiency. (United States)

    Zeegers, Guido P; Günthardt, Barbara F; Zenobi, Renato


    Systematic laser desorption/ionization (LDI) experiments of fullerene-C60 on a wide range of target plate materials were conducted to gain insight into the initial ion formation in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The positive and negative ion signal intensities of precursor, fragment, and cluster ions were monitored, varying both the laser fluence (0-3.53 Jcm(-2)) and the ion extraction delay time (0-950 ns). The resulting species-specific ion signal intensities are an indication for the ionization mechanisms that contribute to LDI and the time frames in which they operate, providing insight in the (MA)LDI primary ionization. An increasing electrical resistivity of the target plate material increases the fullerene-C60 precursor and fragment anion signal intensity. Inconel 625 and Ti90/Al6/V4, both highly electrically resistive, provide the highest anion signal intensities, exceeding the cation signal intensity by a factor ~1.4 for the latter. We present a mechanism based on transient electrical field strength reduction to explain this trend. Fullerene-C60 cluster anion formation is negligible, which could be due to the high extraction potential. Cluster cations, however, are readily formed, although for high laser fluences, the preferred channel is formation of precursor and fragment cations. Ion signal intensity depends greatly on the choice of substrate material, and careful substrate selection could, therefore, allow for more sensitive (MA)LDI measurements. Graphical Abstract ᅟ.

  7. C60 Fullerene as Promising Therapeutic Agent for the Prevention and Correction of Skeletal Muscle Functioning at Ischemic Injury (United States)

    Nozdrenko, D. M.; Zavodovskyi, D. O.; Matvienko, T. Yu.; Zay, S. Yu.; Bogutska, K. I.; Prylutskyy, Yu. I.; Ritter, U.; Scharff, P.


    The therapeutic effect of pristine C60 fullerene aqueous colloid solution (C60FAS) on the functioning of the rat soleus muscle at ischemic injury depending on the time of the general pathogenesis of muscular system and method of administration C60FAS in vivo was investigated. It was found that intravenous administration of C60FAS is the optimal for correction of speed macroparameters of contraction for ischemic muscle damage. At the same time, intramuscular administration of C60FAS shows pronounced protective effect in movements associated with the generation of maximum force responses or prolonged contractions, which increase the muscle fatigue level. Analysis of content concentration of creatine phosphokinase and lactate dehydrogenase enzymes in the blood of experimental animals indicates directly that C60FAS may be a promising therapeutic agent for the prevention and correction of ischemic-damaged skeletal muscle function.

  8. First prediction of inter-Coulombic decay of C60 inner vacancies through the continuum of confined atoms

    CERN Document Server

    De, Ruma; Madjet, Mohamed E; Manson, Steven T; Chakraborty, Himadri S


    Considering the photoionization of Ar@C60 and Kr@C60 endofullerenes, the decay of C60 innershell excitations through the outershell continuum of the confined atom via the inter-Coulombic decay (ICD) pathway is detailed. Excitations to atom-C60 hybrid states demonstrate coherence between ICD and electron-transfer mediated decay (ETMD). This should be the dominant above-threshold decay process for a variety of confined systems, and the strength of these resonances is such that they should be amenable for study by photoelectron spectroscopy.

  9. Study on the Interaction Between C60 Bisadducts and Cyclic Porphyrin Dimer%C60二取代化合物与环状二卟啉相互作用研究

    Institute of Scientific and Technical Information of China (English)

    翁俊迎; 赵威; 章应辉


    通过紫外-可见吸收光谱研究了环状二卟啉与trans-2,tr ans-3,trans-4和e型4种吡咯烷二取代C60衍生物(bis-C60)异构体之间的弱相互作用.研究表明,吡咯烷取代基团的引入使富勒烯与二卟啉的结合常数按C60>单取代C60>二取代C60的顺序降低.4种b is-C60与二卟啉的结合常数变化顺序为trans-2>trans-3≈trans-4>e,表明2个取代基间的相对位置对二取代C60与环状二卟啉间作用有一定影响,分析认为主、客体分子间空间位阻效应的差异是导致这一变化的主要原因.以trans-3 bis-C60/二卟啉复合物为代表,通过密度泛函理论模拟了其几何结构和吸收光谱.

  10. 星状C60(CH3)x(PAN)x共聚物的光致发光研究%Photoluminescence Study of Star-like C60(CH3)x(PAN)x Copolymer

    Institute of Scientific and Technical Information of China (English)

    马国宏; 钱士雄; 陈彧; 蔡瑞芳; 赵太平; 叶学敏



  11. Distribution and biomarkers of Carbon-14 labeled fullerene C60 ([14C(U)]C60) in female rats and mice for up to 30 days after intravenous exposure (United States)

    Sumner, Susan C. J.; Snyder, Rodney W.; Wingard, Christopher; Mortensen, Ninell P.; Holland, Nathan A.; Shannahan, Jonathan H.; Dhungana, Suraj; Pathmasiri, Wimal; Han, Li; Lewin, Anita H.; Fennell, Timothy R.


    A comprehensive distribution study was conducted in female rats and mice exposed to a suspension of uniformly carbon-14 labeled C60 ([14C(U)]C60). Rodents were administered [14C(U)]C60 (~0.9 mg /kg body weight) or 5% PVP-saline vehicle alone via a single tail vein injection. Tissues were collected at 1 hour, 1, 7, 14 and 30 days after administration. A separate group of rodents received 5 daily injections of suspensions of either [14C(U)]C60 or vehicle with tissue collection 14 days post exposure. Radioactivity was detected in over 20 tissues at all time period. The highest concentration of radioactivity in rodents at each time point was in liver, lungs and spleen. Elimination of [14C(U)]C60 was <2% in urine and feces at any 24 hour time points. [14C(U)]C60 and [14C(U)]C60-retinol were detected in liver of rats and together accounted for ~99% and ~56% of the total recovered at 1 and 30 days post exposure, respectively. The blood radioactivity at 1 hour after [14C(U)]C60 exposure was four-fold higher in rats than in mice; blood radioactivity was still in circulation at 30 days post [14C(U)]C60 exposure in both species (<1%). Levels of oxidative stress markers increased by 5 days after exposure and remained elevated, while levels of inflammation markers initially increased and then returned to control values. The level of cardiovascular marker vWF, increased in rats, but remained at control levels in mice. This study demonstrates that [14C(U)]C60 is retained in female rodents with little elimination by 30 days after i.v. exposure, and leads to systemic oxidative stress. PMID:25727383

  12. Accurate calculation of chemical shifts in highly dynamic H2@C60 through an integrated quantum mechanics/molecular dynamics scheme. (United States)

    Jiménez-Osés, Gonzalo; García, José I; Corzana, Francisco; Elguero, José


    A new protocol combining classical MD simulations and DFT calculations is presented to accurately estimate the (1)H NMR chemical shifts of highly mobile guest-host systems and their thermal dependence. This strategy has been successfully applied for the hydrogen molecule trapped into C(60) fullerene, an unresolved and challenging prototypical case for which experimental values have never been reproduced. The dependence of the final values on the theoretical method and their implications to avoid over interpretation of the obtained results are carefully described.

  13. 分子团簇表面吸附敏化ZnO纳米线的第一性原理研究%First-principles study on the sensitization of small molecule adsorbed on ZnO nanowire

    Institute of Scientific and Technical Information of China (English)

    王乐; 刘阳; 徐国堂; 李晓艳; 董前民; 黄杰; 梁培


    ZnO纳米线作为新型太阳能电池结构的重要组成部件之一,其导电能力直接影响到太阳能电池的性能.采用密度泛函理论平面波超软赝势方法,计算并分析了C_2H_6O(乙醇)、C_6H_5FS(4-氟苯硫酚)、C_7HF_7S(4-(三氟甲基L)-2,3,5,6-四氟硫代苯酚)等小分子吸附的六边形结构〈0001〉ZNWs(ZnO纳米线)的几何结构、吸附能和电子结构.首先,通过几何优化得到了不同基团吸附的ZNWs的稳定结构,同时吸附能计算结果表明C_7HF_7S吸附的体系结构最为稳定,且吸附呈现放热反应;其次,为研究表面敏化对导电性能的影响,计算了不同小分子基团吸附下的能带结构和态密度,并利用能带理论分析了表面吸附敏化对禁带宽度的调控机理,结果分析表明小分子表面吸附敏化对ZNWs的电学性能有一定的影响,其中C_7H_7FS和C_6H_5FS分子均发生了不同程度的电荷转移.%The electronic properties of the ZNWs(ZnO nanowire) as one of important part of novel SC(solar cells) are very important, which can greatly affect the performance of the SC.Based on the density function theory combined with the plane-wave ultra soft pseudo-potential method,the structures,the adsorption energies and the electronic structures of the C_2H_6O(ethanol),C_6H_5FS(4- fluoro-benzenethiol),C7HF7FS(2,3,5,6- tetrafluoro-4-(trifluoromethyl) benzenethiol) clusters adsorbed(0001) hexangular ZNWs are calculated.Firstly,the most stable configuration is found out from different adsorbed ones based on the principle of lowest energy by calculating their total energy.The results also indicate that C_7HF_7FS adsorption is energetically favorable.Then,the densities of state and the electronic structures of different adsorbed systems are calculated.Furthermore,the mechanism for adjusting the band-gap of the absorbed system is investigated and the results indicate that the chemical modification of ZNWs

  14. Multiscale Simulation and Modeling of Multilayer Heteroepitactic Growth of C60 on Pentacene. (United States)

    Acevedo, Yaset M; Cantrell, Rebecca A; Berard, Philip G; Koch, Donald L; Clancy, Paulette


    We apply multiscale methods to describe the strained growth of multiple layers of C60 on a thin film of pentacene. We study this growth in the presence of a monolayer pentacene step to compare our simulations to recent experimental studies by Breuer and Witte of submonolayer growth in the presence of monolayer steps. The molecular-level details of this organic semiconductor interface have ramifications on the macroscale structural and electronic behavior of this system and allow us to describe several unexplained experimental observations for this system. The growth of a C60 thin film on a pentacene surface is complicated by the differing crystal habits of the two component species, leading to heteroepitactical growth. In order to probe this growth, we use three computational methods that offer different approaches to coarse-graining the system and differing degrees of computational efficiency. We present a new, efficient reaction-diffusion continuum model for 2D systems whose results compare well with mesoscale kinetic Monte Carlo (KMC) results for submonolayer growth. KMC extends our ability to simulate multiple layers but requires a library of predefined rates for event transitions. Coarse-grained molecular dynamics (CGMD) circumvents KMC's need for predefined lattices, allowing defects and grain boundaries to provide a more realistic thin film morphology. For multilayer growth, in this particularly suitable candidate for coarse-graining, CGMD is a preferable approach to KMC. Combining the results from these three methods, we show that the lattice strain induced by heteroepitactical growth promotes 3D growth and the creation of defects in the first monolayer. The CGMD results are consistent with experimental results on the same system by Conrad et al. and by Breuer and Witte in which C60 aggregates change from a 2D structure at low temperature to 3D clusters along the pentacene step edges at higher temperatures.

  15. Supramolecular Complexation Behavior of Novel Cyclotrivera-trylene Derivatives with Benzoate Pendants with C60

    Institute of Scientific and Technical Information of China (English)

    ZHAN Hao-Oiang; JIANG Xi-Kui; LI Zhan-Ting


    Four novel cyclotriveratrylene (CTV) derivatives with threebenzoate pendants bearing different aliphatic chains have been prepared in good yields,starting from.CTV.The complexa-tion behavior of these CTV derivatives towards C60 in arene solvents has been measured by UV-visible spectroscopy and high complexation constants are obtained.It is observed the me complexation is promoted by introducing methyl ester groups to the aromatic pendants, while this pro-moting effect is reduced when the methyl groups are replaced by longer alkyl groups.

  16. Strong Room-Temperature Photoluminescence from the Novel Adduct of C60 with Aliphatic Amines

    Institute of Scientific and Technical Information of China (English)


    Strong room-temperature photoluminescence from the adducts of C60 reacting with five different aliphatic amines, namely propylethylamine (PPA), n-butyl amine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and diethylamine (DEA), was firstly found from their toluene solution at relatively shorter wavelength around 519 nm.The fluorescence intensity has a good correlation with the length of n-alkyl group chain, the steric position and concentration of different amines and setting of solution as well as the UV-radiation. Their fluorescence quenching by concentration and by aromatic electron-donor N,N-dimethylaniline (DMA) were first investigated and determined.

  17. Preparation of C60(O)n-ZnO nanocomposite under electric furnace and photocatalytic degradation of organic dyes. (United States)

    Cho, Bum Hwi; Oh, Youn Jun; Mun, Sang Mi; Ko, Weon Bae


    Zinc oxide (ZnO) nanoparticles were synthesized sonochemically by applying ultrasonic irradiation to a mixed aqueous-alcoholic solution of zinc nitrate with sodium hydroxide at room temperature. The morphology and optical properties of the ZnO nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis spectroscopy. The C60(O)n nanoparticles were synthesized by heating a mixture of C60 and 3-chloroperoxybenzoic acid in a benzene solvent under the reflux system. The heated C60(O)n-ZnO nanocomposite was synthesized in an electric furnace at 700 degrees C for two hours. The heated C60(O)n-ZnO nanocomposite was characterized by XRD, SEM, and TEM, and examined as a catalyst in the photocatalytic degradation of organic dyes by UV-vis spectroscopy. The photocatalytic effect of the heated C60(O)n-ZnO nanocomposite was evaluated by a comparison with that of unheated C60(O)n nanoparticles, heated C60(O)n nanoparticles, and unheated C60(O)n-ZnO in organic dyes, such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under ultraviolet light at 365 nm.

  18. In silico properties characterization of water-soluble γ-cyclodextrin bi-capped C60 complex

    DEFF Research Database (Denmark)

    Cao, Ruyin; Wu, Shanshan


    Cyclodextrin-related host-guest encapsulation is pivotal to modulate the solubility of C60, thereby promoting its potential therapeutic applications. Here we present a computational study on γ-cyclodextrin bi-capped C60 complex, probing characteristics for all the possible stoichiometry in aqueous...

  19. Picosecond to millisecond photoexcitation dynamics in blends of C 60 with poly( p-phenylene vinylene) polymers (United States)

    Frolov, S. V.; Lane, P. A.; Ozaki, M.; Yoshino, K.; Vardeny, Z. V.


    We compare photoexcitation dynamics in films of pristine and C 60-mixed 2,5-dioctyloxy poly( p-phenylene vinylene) (DOO-PPV) using ps transient and cw photoinduced absorption (PA), and PA-detected magnetic resonance (PADMR). We conclude that C 60 doping is relatively inefficient in DOO-PPV. Consequently, the instantaneous exciton photogeneration yield remains high (close to 1) even at high C 60 concentrations. However, as the C 60 concentration increases up to 10 molar percent, the stimulated emission lifetime and cw photoluminescence intensity decrease together by about an order of magnitude due to dissociation of the singlet excitons at C 60 related defect centers into intrachain polaron pairs, which were identified by PADMR.

  20. Production of anti-fullerene C60 polyclonal antibodies and study of their interaction with a conjugated form of fullerene (United States)

    Hendrickson, O. D.; Fedyunina, N. S.; Martianov, A. A.; Zherdev, A. V.; Dzantiev, B. B.


    The aim of this study was to produce anti-fullerene C60 antibodies for the development of detection systems for fullerene C60 derivatives. To produce anti-fullerene C60 antibodies, conjugates of the fullerene C60 carboxylic derivative with thyroglobulin, soybean trypsin inhibitor, and bovine serum albumin were synthesized by carbodiimide activation and characterized. Immunization of rabbits by the conjugates led to the production of polyclonal anti-fullerene antibodies. The specificity of the immune response to fullerene was investigated. Indirect competitive immunoenzyme assay was developed for the determination of conjugated fullerene with detection limits of 0.04 ng/mL (calculated for coupled C60) and 0.4 ng/mL (accordingly to total fullerene-protein concentration).

  1. In Silico Olefin Metathesis with Ru-Based Catalysts Containing N-Heterocyclic Carbenes Bearing C60 Fullerenes. (United States)

    Martínez, Juan Pablo; Vummaleti, Sai Vikrama Chaitanya; Falivene, Laura; Nolan, Steven P; Cavallo, Luigi; Solà, Miquel; Poater, Albert


    Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene as the substrate, focusing mainly on the thermodynamic stability of all possible reaction intermediates. Our results suggest that complex B bearing an electron-withdrawing N-heterocyclic carbene improves the performance of unannulated complex A. The efficiency of complex B is only surpassed by complex A when the backbone of the N-heterocyclic carbene of complex A is substituted by two amino groups. The particular performance of complexes B and C has to be attributed to electronic factors, that is, the electronic-donating capacity of modified SIMes ligand rather than steric effects, because the latter are predicted to be almost identical for complexes B and C when compared to those of A. Overall, this study indicates that such Ru-based complexes B and C might have the potential to be effective olefin metathesis catalysts.

  2. In Silico Olefin Metathesis with Ru-Based Catalysts Containing N-Heterocyclic Carbenes Bearing C60Fullerenes

    KAUST Repository

    Martínez, Juan Pablo


    Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene as the substrate, focusing mainly on the thermodynamic stability of all possible reaction intermediates. Our results suggest that complex B bearing an electron-withdrawing N-heterocyclic carbene improves the performance of unannulated complex A. The efficiency of complex B is only surpassed by complex A when the backbone of the N-heterocyclic carbene of complex A is substituted by two amino groups. The particular performance of complexes B and C has to be attributed to electronic factors, that is, the electronic-donating capacity of modified SIMes ligand rather than steric effects, because the latter are predicted to be almost identical for complexes B and C when compared to those of A. Overall, this study indicates that such Ru-based complexes B and C might have the potential to be effective olefin metathesis catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Interface between C60 and Ag on nanostructured plasmonic Ag gratings: A SERS study (United States)

    Khosroabadi, Akram A.; Matz, Dallas L.; Gangopadhyay, Palash; Pemberton, Jeanne E.; Norwood, Robert A.


    Nanostructured electrodes and interfaces can enhance light absorption in organic solar cells due to efficient light harvesting. Ultrathin films of an active layer (C60) deposited on nanostructured grating electrodes show more absorption as a result of increased light trapping. Plasmonic nanostructured electrodes with various geometries and dimensions have been fabricated on printed polyacrylonitrile (PAN) and subsequently characterized. Surface enhanced Raman scattering (SERS) measurements show significant signal enhancement (over two orders of magnitude) on nanostructured samples when compared to planar Ag substrates due to local electromagnetic field enhancement. Furthermore, conversion of PAN to graphitic carbon is evidenced in SERS spectra. The surface area was determined using underpotential deposition (UPD) of thallium and agrees with the geometric surface area calculated from SEM images. The FDTD simulated electric field distribution inside the samples confirms the experimental results. A 60 fold increase in the electric field results in three to four orders of magnitude enhancement in the SERS signal depending on the dimensions of the pillars and gratings. Further study of the interaction between a top organic layer (C60) and the Ag electrode will help us to understand the nanoscale charge transfer rate critical to optimization and design of efficient organic solar cells.

  4. Strong-field effects in the photo-emission spectrum of the C$_{60}$ fullerene

    CERN Document Server

    Gao, Cong-Zhang; Kluepfel, Peter; Meier, Chris; Reinhard, Paul-Gerhard; Suraud, Eric


    Considering C$_{60}$ as a model system for describing field emission from the extremity of a carbon nanotip, we explore electron emission from this fullerene excited by an intense, near-infrared, few-cycle laser pulse ($10^{13}$-$10^{14}~{\\rm W/cm}^2$, 912 nm, 8-cycle). To this end, we use time-dependent density functional theory augmented by a self-interaction correction. The ionic background of C$_{60}$ is described by a soft jellium model. Particular attention is paid to the high energy electrons. Comparing the spectra at different emission angles, we find that, as a major result of this study, the photoelectrons are strongly peaked along the laser polarization axis forming a highly collimated electron beam in the forward direction, especially for the high energy electrons. Moreover, the high-energy plateau cut-off found in the simulations agrees well with estimates from the classical three-step model. We also investigate the build-up of the high-energy part of a photoelectron spectrum by a time-resolved a...


    Directory of Open Access Journals (Sweden)

    Álvaro Duarte


    Full Text Available  Se sintetizaron dos fulleroles por hidrólisis básica del compuesto C60Br24 a 60°C, con 22 horas de reacción, en presencia de oxígeno atmosférico y utilizando relaciones molares de KOH/C60Br24 de 109 y 184. La geometría inicial no se mantiene al sustituir los átomos de bromo y los fulleroles obtenidos son de naturaleza aniónica y poseen una estructura compleja que incluye grupos hidroxilo y grupos hemicetal. Se encontró que el tratamiento ácido o el intercambio iónico con resina mixta tipo  H+/OH-, ocasionan la aparición de grupos carbonilos dentro de su estructura. Los productos se caracterizaron por análisis elemental, espectroscopia infrarroja, UV-Vis, 1H-RMN, MALDI-TOF, TGA y DSC.

  6. Modelling of C2 addition route to the formation of C60

    CERN Document Server

    Khan, Sabih D


    To understand the phenomenon of fullerene growth during its synthesis, an attempt is made to model a minimum energy growth route using a semi-empirical quantum mechanics code. C2 addition leading to C60 was modelled and three main routes, i.e. cyclic ring growth, pentagon and fullerene road, were studied. The growth starts with linear chains and, at n = 10, ring structures begins to dominate. The rings continue to grow and, at some point n > 30, they transform into close-cage fullerenes and the growth is shown to progress by the fullerene road until C60 is formed. The computer simulations predict a transition from a C38 ring to fullerene. Other growth mechanisms could also occur in the energetic environment commonly encountered in fullerene synthesis, but our purpose was to identify a minimal energy route which is the most probable structure. Our results also indicate that, at n = 20, the corannulene structure is energetically more stable than the corresponding fullerene and graphene sheet, however a ring str...

  7. A First Principle Comparative Study on Chemisorption of H2 on C60, C80, and Sc3N@C80 in Gas Phase and Chemisorption of H2 on Solid Phase C60

    Directory of Open Access Journals (Sweden)

    Hongtao Wang


    Full Text Available The chemisorptions of H2 on fullerenes C60 and C80, endofullerene Sc3C@C80 and solid C60 were comparatively studied. A chain reaction mechanism for dissociative adsorption of H2 on solid C60 is proposed under high pressure. The breaking of H–H bond is concerted with the formation of two C–H bonds on two adjacent C60 in solid phase. The adsorption process is facilitated by the application of high pressure. The initial H2 adsorption on two adjacent C60 gives a much lower barrier 1.36 eV in comparison with the barrier of adsorption on a single C60 (about 3.0 eV. As the stereo conjugate aromaticity of C60 is destructed by the initial adsorption, some active sites are created. Hence the successive adsorption becomes easier with much low barriers (0.6 eV. In addition, further adsorption can create new active sites for the next adsorption. Thus, a chain reaction path is formed with the initial adsorption dominating the whole adsorption process.

  8. Extraction and HPLC- UV Analysis of C60, C70, and [6,6]-phenyl C61-butyric acid methyl ester in Synthetic and Natural Waters (United States)

    Studies have shown that C60 fullerene can form stable colloidal suspensions in water that result in C60 aqueous concentrations many orders of magnitude above C60's aqueous solubility; however, quantitative methods for the analysis of C60 and other fullerenes in environmental medi...

  9. Synthesis of gold nano-wire and nano-dumbbell shaped colloids and AuC60 nano-clusters (United States)

    Landon, Preston B.; Jarvis, Brandon C.; Gilleland, Cody L.; Renfro, Tim; Gutierrez, Jose; Synowczynski, Jennifer; Hirsch, Samuel G.; Glosser, Robert


    A technique for the fabrication of colloidal gold nano-wire and nano-dumbbell shaped particles using carbon nanotubes and rod shaped viruses as templates is described. The gold (Au) encapsulation process was accomplished by the precipitation of gold chloride from aqueous solutions. When this process was conducted in the presence of hydroxylated C60, small pieces of phase-separated composites of AuC60 appeared to have formed. These nano-clusters may turn out to be large noble metal analogs of the alkali metal fullerides with the smallest geometrically possible Au aggregate consisting of 55 gold atoms. The existence of noble metal fullerene composites has been previously theorized. The alkali metal fullerides are examples of phase separated solids and have exhibited superconductivity with temperatures as high 33K. The mechanism required for the binding energy between C60 and gold has been observed to exist between C60 and many of the mirror metals (Al, Ag, Au, Cu, Ni). This binding energy is a charge transfer from the metal Fermi level into the C60 LUMO. If this bonding energy, is greater than the metals coagulation energy an Au/C60 size terminated mechanism during the formation of the gold aggregates by the adhesion of C60 to the surface is energetically favorable.

  10. Neuronal uptake and intracellular superoxide scavenging of a fullerene (C60)-poly(2-oxazoline)s nanoformulation

    KAUST Repository

    Tong, Jing


    Fullerene, the third allotrope of carbon, has been referred to as a "radical sponge" because of its powerful radical scavenging activities. However, the hydrophobicity and toxicity associated with fullerene limits its application as a therapeutic antioxidant. In the present study, we sought to overcome these limitations by generating water-soluble nanoformulations of fullerene (C(60)). Fullerene (C(60)) was formulated with poly(N-vinyl pyrrolidine) (PVP) or poly(2-alkyl-2-oxazoline)s (POx) homopolymer and random copolymer to form nano-complexes. These C(60)-polymer complexes were characterized by UV-vis spectroscopy, infrared spectroscopy (IR), dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Cellular uptake and intracellular distribution of the selected formulations in catecholaminergic (CATH.a) neurons were examined by UV-vis spectroscopy, immunofluorescence and immunogold labeling. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the ability of these C(60)-polymer complexes to scavenge superoxide. Their cytotoxicity was evaluated in three different cell lines. C(60)-POx and C(60)-PVP complexes exhibited similar physicochemical properties and antioxidant activities. C(60)-poly(2-ethyl-2-oxazoline) (PEtOx) complex, but not C(60)-PVP complex, were efficiently taken up by CATH.a neurons and attenuated the increase in intra-neuronal superoxide induced by angiotensin II (Ang II) stimulation. These results show that C(60)-POx complexes are non-toxic, neuronal cell permeable, superoxide scavenging antioxidants that might be promising candidates for the treatment of brain-related diseases associated with increased levels of superoxide.

  11. Attosecond time delay in the photoionization of endohedral atoms A@C$_{60}$: A new probe of confinement resonances

    CERN Document Server

    Deshmukh, P C; Saha, S; Kheifets, A S; Dolmatov, V K; Manson, S T


    The effects of confinement resonances on photoelectron group delay (Wigner time delay) following ionization of an atom encapsulated inside a C$_{60}$ cage have been studied theoretically using both relativistic and non-relativistic random phase approximations. The results indicate clearly the resonant character of the confinement oscillations in time delay of the $4d$ shell of Xe@C$_{60}$ and present a most direct manifestation of Wigner time delay. These oscillations were missed in a previous theoretical investigation of Ar@C$_{60}$ [PRL 111, 203003 (2013)

  12. Transmission secondary ion mass spectrometry using 5 MeV C60+ ions (United States)

    Nakajima, K.; Nagano, K.; Suzuki, M.; Narumi, K.; Saitoh, Y.; Hirata, K.; Kimura, K.


    In the secondary ion mass spectrometry (SIMS), use of cluster ions has an advantage of producing a high sensitivity of intact large molecular ions over monatomic ions. This paper presents further yield enhancement of the intact biomolecular ions by measuring the secondary ions emitted in the forward direction. Phenylalanine amino acid films deposited on self-supporting thin Si3N4 films were bombarded with 5 MeV C60 ions. Secondary ions emitted in the forward and backward directions were measured. The yield of intact phenylalanine molecular ions emitted in the forward direction is significantly enhanced compared to the backward direction while fragment ions are suppressed. This suggests a large potential of using transmission cluster ion SIMS for the analysis of biological materials.

  13. Plasma and Gaseous Nitrocarburizing of C60W Steel for Tribological Applications

    Institute of Scientific and Technical Information of China (English)

    M.Mirjani; F. Ashrafizadeh; A. Shafyei


    A comparison has been made between plasma and gas nitrocarburizing processes for C60W steel in terms of structural features of the layers and the tribological properties of the specimens. Gaseous treatments were performed in a sealed quench industrial furnace in optimized process cycles. For plasma nitrocarburizing, a semi - industrial size unit was operated at a range of process parameters. Experimental results indicate that increasing the treatment time increases the thickness of the compound layer but lowers the wear resistance. Plasma treatment produced a more effective case depth compared with gaseous process, providing a better uniformity. Analysis of X-ray diffraction patterns indicated that the compound layer in gas nitrocarburizing consisted of both ε and γ' phases, whereas in plasma nitrocarburizing the ε phase was not detected.

  14. C60 as an Efficient n-Type Compact Layer in Perovskite Solar Cells. (United States)

    Wojciechowski, Konrad; Leijtens, Tomas; Siprova, Svetlana; Schlueter, Christoph; Hörantner, Maximilian T; Wang, Jacob Tse-Wei; Li, Chang-Zhi; Jen, Alex K-Y; Lee, Tien-Lin; Snaith, Henry J


    Organic-inorganic halide perovskite solar cells have rapidly evolved over the last 3 years. There are still a number of issues and open questions related to the perovskite material, such as the phenomenon of anomalous hysteresis in current-voltage characteristics and long-term stability of the devices. In this work, we focus on the electron selective contact in the perovskite solar cells and physical processes occurring at that heterojunction. We developed efficient devices by replacing the commonly employed TiO2 compact layer with fullerene C60 in a regular n-i-p architecture. Detailed spectroscopic characterization allows us to present further insight into the nature of photocurrent hysteresis and charge extraction limitations arising at the n-type contact in a standard device. Furthermore, we show preliminary stability data of perovskite solar cells under working conditions, suggesting that an n-type organic charge collection layer can increase the long-term performance.

  15. Friction and diffusion dynamics of adsorbates at surfaces

    NARCIS (Netherlands)

    Fusco, C.


    A theoretical study of the motion of adsorbates (e. g. atoms, molecules or clusters) on solid surfaces is presented, with a focus on surface diffusion and atomic-scale friction. These two phenomena are inextricably linked, because when an atomic or molecular adsorbate diffuses, or is pulled, it unav

  16. Influence of surface morphology evolution of SubPc layers on the performance of SubPc/C60 organic photovoltaic cells (United States)

    Kim, Jinhyun; Yim, Sanggyu


    In this study, small-molecule organic solar cells based on choloro[subphthalocyaninato]boron (III) (SubPc) as an electron donor and fullerene (C60) as an electron acceptor were fabricated by varying the thickness, d, of the SubPc layer. The power conversion efficiency was maximized to 1.8% at d ˜ 130 Å due to the relatively large values of the short-circuit current density (JSC) and fill factor (FF). This optimal thickness was also strongly related to the surface morphology evolution of the SubPc thin films. The corrugated surface nanostructures were continually formed until the thickness of the film increased up to 130 Å, which is advantageous for the formation of an interdigitated electron donor-acceptor interface. In contrast, for films thicker than 130 Å, the corrugated surface structures were filled with subsequently deposited molecules, leading to a smoother morphology and consequently reduced JSC and FF value of the cells.

  17. Impact of electron delocalization on the nature of the charge-transfer states in model pentacene/C60 Interfaces: A density functional theory study

    KAUST Repository

    Yang, Bing


    Electronic delocalization effects have been proposed to play a key role in photocurrent generation in organic photovoltaic devices. Here, we study the role of charge delocalization on the nature of the charge-transfer (CT) states in the case of model complexes consisting of several pentacene molecules and one fullerene (C60) molecule, which are representative of donor/acceptor heterojunctions. The energies of the CT states are examined by means of time-dependent density functional theory (TD-DFT) using the long-range-corrected functional, ωB97X, with an optimized range-separation parameter, ω. We provide a general description of how the nature of the CT states is impacted by molecular packing (i.e., interfacial donor/acceptor orientations), system size, and intermolecular interactions, features of importance in the understanding of the charge-separation mechanism.

  18. Characterization of Plasma Gun with TiH2/C60 Cartridge for Disruption Mitigation in Tokamaks (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.; HyperV Technologies Corp. Team


    Impurity injection for disruption mitigation in tokamaks must be faster than growth time of plasma instabilities, requires sufficient mass to get critical electron density, high penetrability, and large assimilation fraction in the core plasma, with rapid impurity redistribution over the whole plasma. FAR-TECH, Inc. proposed the innovative idea to use hyper-velocity (>30 km/s), high-density (>1023 m-3) C60/C plasma jets with high ram pressure to deliver the impurity mass in plasma accelerator. We report the complete characterization of the TiH2/C60 cartridge with 5 kJ capacitive driver which demonstrated the capability of producing >30 mg of C60 gas in coaxial plasma gun (~35 cm length) prototype with TiH2/C60 cartridge for a small scale, proof-of-principle experiment on a tokamak. Work supported by the US DOE DE-FG02-08ER85196 grant.

  19. Toxicity and bioaccumulation of xenobiotic organic compounds in the presence of aqueous suspensions of aggregates of nano-C60

    DEFF Research Database (Denmark)

    Baun, Anders; Sørensen, Sara Nørgaard; Rasmussen, R.F.


    , pentachlorophenol (PCP), and phenanthrene) were used as model compounds, representing different physico-chemical properties and toxic modes of action. The aggregates of nano-C60 formed over 2 months of stirring in water were mixed with model compounds 5 days prior to testing. Uptake and excretion of phenanthrene...... of the presence of C60-aggregates. In bioaccumulation studies with phenanthrene in D. magna it was found that the uptake of phenanthrene was faster when C60 was present in suspension and that a 1.7 times higher steady-state concentration was reached in the animals. However, a very fast clearance took place when...... animals were transferred to clean water resulting in no accumulation of phenanthrene. This study is the first to demonstrate the influence of C60-aggregates on aquatic toxicity and bioaccumulation of other environmentally relevant contaminants. The data provided underline that not only the inherent...





    The influence of polymer-fullerene interactions and fullerene aggregation on the thermal stability of polymethyl-methacrylate-fullerene C 60 nanocomposite has been studied by means of thermal desorption mass-spectrometry and the UV-Vis absorption spectroscopy.

  1. Water-soluble fullerene (c60 inhibits the development of arthritis in the rat model of arthritis

    Directory of Open Access Journals (Sweden)

    Kazuo Yudoh


    Full Text Available Kazuo Yudoh1, Rie Karasawa1, Kayo Masuko2, Tomohiro Kato2 1Institute of Medical Science, 2Department of Biochemistry, St. Marianna University School of Medicine, Kawasaki, JapanAbstract: Recently, it has been demonstrated that oxygen free radicals have an important role as a signaling messenger in the development of inflammation and osteoclastogenesis, suggesting the implication of oxygen free radicals in the pathogenesis of arthritis. The aim of this study was to examine the potential of a strong free-radical scavenger, water-soluble fullerene (C60, as a protective agent against synovitis in arthritis, both in vitro and in vivo. In the presence or absence of C60 (0.1, 1.0, 10.0 µM, human synovial fibroblasts, synovial infiltrating lymphocytes or macrophages were incubated with tumor necrosis factor-α (TNF-α (10.0 ng/mL, and the production of proinflammatory cytokines by the individual cells were analyzed. C60 significantly suppressed the TNF-α-induced production of proinflammatory cytokines in synovial fibroblasts, synovial infiltrating lymphocytes and macrophages in vitro. Adjuvant induced arthritic rats were used as an animal model of arthritis. Rats were divided into two subgroups: control and treatment with C60 at 10.0 µM. The left ankle joint was injected intraarticularly with water-soluble C60 (20 µl in the C60-treated group, while, as a control, the left ankle joint in the control rats received phosphate-buffered saline (20 µl, once weekly for eight weeks. Ankle joint tissues were prepared for histological analysis. In adjuvant-induced arthritic rats, intra-articular treatment with C60 in vivo reduced synovitis and alleviated bone resorption and destruction in the joints, while control ankle joints showed progression of synovitis and joint destruction with time. These findings indicate that C60 is a potential therapeutic agent for inhibition of arthritis.Keywords: fullerene, inflammation, arthritis, synovitis, bone resorption

  2. Immunostimulatory properties and enhanced TNF- α mediated cellular immunity for tumor therapy by C60(OH)20 nanoparticles (United States)

    Liu, Ying; Jiao, Fang; Qiu, Yang; Li, Wei; Qu, Ying; Tian, Chixia; Li, Yufeng; Bai, Ru; Lao, Fang; Zhao, Yuliang; Chai, Zhifang; Chen, Chunying


    Publications concerning the mechanism of biological activity, especially the immunological mechanism of C60(OH)20 nanoparticles, are relatively limited. However, the structure and characteristics of this carbon allotrope have been widely investigated. In this paper, we have demonstrated that water-soluble C60(OH)20 nanoparticles have an efficient anti-tumor activity in vivo, and show specific immunomodulatory effects to the immune cells, such as T cells and macrophages, both in vivo and in vitro. For example, C60(OH)20 nanoparticles can increase the production of T-helper cell type 1 (Th1) cytokines (IL-2, IFN- γ and TNF-α), and decrease the production of Th2 cytokines (IL-4, IL-5 and IL-6) in serum samples. On the other hand, C60(OH)20 nanoparticles show almost no adverse effect to the viability of immune cells in vitro but stimulate the immune cells to release more cytokines, in particular TNF- α, which plays a key role in the cellular immune process to help eliminate abnormal cells. TNF- α production increased almost three-fold in treated T lymphocytes and macrophages. Accordingly, we conclude that C60(OH)20 nanoparticles have an efficient anti-tumor activity and this effect is associated with an increased CD4+/CD8+ lymphocyte ratio and the enhancement of TNF- α production. The data suggest that C60(OH)20 nanoparticles can improve the immune response to help to scavenge and kill tumor cells.

  3. Direct observation of photocarrier electron dynamics in C60 films on graphite by time-resolved two-photon photoemission (United States)

    Shibuta, Masahiro; Yamamoto, Kazuo; Ohta, Tsutomu; Nakaya, Masato; Eguchi, Toyoaki; Nakajima, Atsushi


    Time-resolved two-photon photoemission (TR-2PPE) spectroscopy is employed to probe the electronic states of a C60 fullerene film formed on highly oriented pyrolytic graphite (HOPG), acting as a model two-dimensional (2D) material for multi-layered graphene. Owing to the in-plane sp2-hybridized nature of the HOPG, the TR-2PPE spectra reveal the energetics and dynamics of photocarriers in the C60 film: after hot excitons are nascently formed in C60 via intramolecular excitation by a pump photon, they dissociate into photocarriers of free electrons and the corresponding holes, and the electrons are subsequently detected by a probe photon as photoelectrons. The decay rate of photocarriers from the C60 film into the HOPG is evaluated to be 1.31 × 1012 s‑1, suggesting a weak van der Waals interaction at the interface, where the photocarriers tentatively occupy the lowest unoccupied molecular orbital (LUMO) of C60. The photocarrier electron dynamics following the hot exciton dissociation in the organic thin films has not been realized for any metallic substrates exhibiting strong interactions with the overlayer. Furthermore, the thickness dependence of the electron lifetime in the LUMO reveals that the electron hopping rate in C60 layers is 3.3 ± 1.2 × 1013 s‑1.

  4. Influence of fullerene (C60) on soil bacterial communities: aqueous aggregate size and solvent co-introduction effects (United States)

    Tong, Zhong-Hua; Bischoff, Marianne; Nies, Loring F.; Carroll, Natalie J.; Applegate, Bruce; Turco, Ronald F.


    Fullerene C60 nanoparticles are being used in broad range of applications. It is important to assess their potential impacts in the environment. We evaluated the effects of C60 introduced as aqueous suspensions of nC60 aggregates of different particle size or via organic solvents on soils with different organic matter contents in this study. Impacts of the application were evaluated by measuring total microbial biomass, metabolic activity and bacterial community structure. Results show that nC60 aggregates, introduced as an aqueous suspension, had size-dependent effects on soil bacterial community composition in the low organic matter system, but induced minimal change in the microbial biomass and metabolic activity in soils with both high and low organic matter contents. Fullerene C60, co-introduced via an organic solvent, did not influence the response of soil microbes to the organic solvents. Our results suggest that nC60 aggregates of smaller size may have negative impact on soil biota and soil organic matter may play a key role in modulating the environmental effect of nanomaterials.

  5. Immunotoxicity of nanoparticles: a computational study suggests that CNTs and C60 fullerenes might be recognized as pathogens by Toll-like receptors (United States)

    Turabekova, M.; Rasulev, B.; Theodore, M.; Jackman, J.; Leszczynska, D.; Leszczynski, J.


    Over the last decade, a great deal of attention has been devoted to study the inflammatory response upon exposure to multi/single-walled carbon nanotubes (CNTs) and different fullerene derivatives. In particular, carbon nanoparticles are reported to provoke substantial inflammation in alveolar and bronchial epithelial cells, epidermal keratinocytes, cultured monocyte-macrophage cells, etc. We suggest a hypothetical model providing the potential mechanistic explanation for immune and inflammatory responses observed upon exposure to carbon nanoparticles. Specifically, we performed a theoretical study to analyze CNT and C60 fullerene interactions with the available X-ray structures of Toll-like receptors (TLRs) homo- and hetero-dimer extracellular domains. This assumption was based on the fact that similar to the known TLR ligands both CNTs and fullerenes induce, in cells, the secretion of certain inflammatory protein mediators, such as interleukins and chemokines. These proteins are observed within inflammation downstream processes resulted from the ligand molecule dependent inhibition or activation of TLR-induced signal transduction. Our computational studies have shown that the internal hydrophobic pockets of some TLRs might be capable of binding small-sized carbon nanostructures (5,5 armchair SWCNTs containing 11 carbon atom layers and C60 fullerene). High binding scores and minor structural alterations induced in TLR ectodomains upon binding C60 and CNTs further supported our hypothesis. Additionally, the proposed hypothesis is strengthened by the indirect experimental findings indicating that CNTs and fullerenes induce an excessive expression of specific cytokines and chemokines (i.e. IL-8 and MCP1).Over the last decade, a great deal of attention has been devoted to study the inflammatory response upon exposure to multi/single-walled carbon nanotubes (CNTs) and different fullerene derivatives. In particular, carbon nanoparticles are reported to provoke

  6. Clinical evaluation of fullerene-C60 dissolved in squalane for anti-wrinkle cosmetics. (United States)

    Kato, Shinya; Taira, Hikaru; Aoshima, Hisae; Saitoh, Yasukazu; Miwa, Nobuhiko


    Highly purified and organic solvent-free fullerene-C60 was dissolved, at nearly saturated concentration of 278 ppm, in squalane prepared from olive oil, which is designated as LipoFullerene (LF-SQ) and was examined for usage as a cosmetic ingredient with antioxidant ability. The aim of this study was to assess the anti-wrinkle formation efficacy of LF-SQ in subjects. A total of 23 Japanese women (group I: age 38.9 +/- 3.8, n = 11, group II; age 39.4 +/- 4.3, n = 12) were enrolled in an 8-week trial of LF-SQ blended cream in a randomized, matched pair double-blind study. The LF-SQ cream was applied twice daily on the right or left half of the face, and squalane blended cream (without fullerene-C60) was applied as the placebo on another half of the face. As clinical evaluations of wrinkle grades, visual observation and photographs, and silicone replicas of both crow's feet areas were taken at baseline (0 week) and at 4th and 8th weeks. Skin replicas were analyzed using an optical profilometry technique. The wrinkle and skin-surface roughness features were calculated and statistically analyzed. Subsequently, trans-epidermal water loss (TEWL), moisture levels of the stratum corneum, and visco-elasticity (suppleness: RO and elasticity: R7) were measured on cheeks by instrumental analysis. LF-SQ cream enhanced the skin moisture and the anti-wrinkle formation. LF-SQ cream that was applied on a face twice daily was not effective at 4th week, but significantly more effective than the placebo at 8th week (p < 0.05) without severe side effects. The roughness-area ratio showed significant improvement (p < 0.05) at 8th week with LF-SQ cream as compared to 0 week with LF-SQ cream, but no significant difference was detected between LF-SQ cream and the placebo. We suggest that LF-SQ could be used as an active ingredient for wrinkle-care cosmetics.

  7. Nitric oxide adsorbed on zeolites: EPR studies. (United States)

    Yahiro, Hidenori; Lund, Anders; Shiotani, Masaru


    CW-EPR studies of NO adsorbed on sodium ion-exchanged zeolites were focused on the geometrical structure of NO monoradical and (NO)2 biradical formed on zeolites. The EPR spectrum of NO monoradical adsorbed on zeolite can be characterized by the three different g-tensor components and the resolved y-component hyperfine coupling with the 14N nucleus. Among the g-tensor components, the value of g(zz) is very sensitive to the local environment of zeolite and becomes a measure of the electrostatic field in zeolite. The temperature dependence of the g-tensor demonstrated the presence of two states of the Na-NO adduct, in rigid and rotational states. The EPR spectra of NO adsorbed on alkaline metal ion-exchanged zeolite and their temperature dependency are essentially the same as that on sodium ion-exchanged zeolite. On the other hand, for NO adsorbed on copper ion-exchanged zeolite it is known that the magnetic interaction between NO molecule and paramagnetic copper ion are observable in the spectra recorded at low temperature. The signals assigned to (NO)2 biradical were detected for EPR spectrum of NO adsorbed on Na-LTA. CW-EPR spectra as well as their theoretical calculation suggested that the two NO molecules are aligned along their N-O bond axes. A new procedure for automatical EPR simulation is described which makes it possible to analyze EPR spectrum easily. In the last part of this paper, some instances when other nitrogen oxides were used as a probe molecule to characterize the zeolite structure, chemical properties of zeolites, and dynamics of small molecules were described on the basis of selected literature data reported recently.

  8. In Silico Study of Spacer Arm Length Influence on Drug Vectorization by Fullerene C60

    Directory of Open Access Journals (Sweden)

    Haifa Khemir


    Full Text Available This work studies theoretically the effect of spacer arm lengths on the characteristics of a fullerene C60-based nanovector. The spacer arm is constituted of a carbon chain including a variable number of methylene groups (n = 2–11. To improve the ability of the fullerene carriage, two arms are presented simultaneously through a malonyl bridge. Then the evolution of selected physicochemical parameters is monitored as a function of the spacer arm length and the angle between the two arms. We show here that while the studied characteristics are almost independent of the spacer arm length or vary monotonically with it, the dipole moment and its orientation vary periodically with the parity of the number of carbon atoms. This periodicity is related to both modules and orientations of dipole moments of the spacer arms. In the field of chemical synthesis, these results highlight the importance of theoretical calculations for the optimization of operating conditions. In the field of drug discovery, they show that theoretical calculations of the chemical properties of a drug candidate can help predict its in vivo behaviour, notably its bioavailability and biodistribution, which are known to be tightly dependent of its polarity.

  9. The detection of C60 in the well-characterized planetary nebula M1-11

    CERN Document Server

    Otsuka, Masaaki; Hyung, S; Sargent, B A; Meixner, M; Tajitsu, A; Yanagisawa, K


    We performed multiwavelength observations of the young planetary nebula (PN) M1-11 and obtained its elemental abundances, dust mass, and the evolutionary status of the central star. The AKARI/IRC, VLT/VISIR, and Spitzer/IRS spectra show features due to carbon-rich dust, such as the 3.3, 8.6, and 11.3 um features due to polycyclic aromatic hydrocarbons (PAHs), a smooth continuum attributable to amorphous carbon, and the broad 11.5 and 30 um features often ascribed to SiC and MgS, respectively. We also report the presence of an unidentified broad feature at 16-22 um, similar to the feature found in Magellanic Cloud PNe with either C-rich or O-rich gas-phase compositions. We identify for the first time in M1-11 spectral lines at 8.5 (blended with PAH), 17.3, and 18.9 um that we attribute to the C60 fullerene. This identification is strengthened by the fact that other Galactic PNe in which fullerenes are detected, have similar central stars, similar gas-phase abundances, and a similar dust composition to M1-11. T...

  10. A low voltage and small hysteresis C60 thin film transistor*

    Institute of Scientific and Technical Information of China (English)

    Zhou Jianlin; Chen Rengang


    Organic thin film transistors with C60 as an n-type semiconductor have been fabricated. A tantalum pentoxide (Ta2O5)/poly-methylmethacrylate (PMMA) double-layer structured gate dielectric was used. The Ta2O5 layer was prepared by using a simple solution-based and economical anodization technique. Our results demonstrate that double gate insulators can combine the advantage of Ta2O5 with high dielectric constant and polymer insulator for a better interface with the organic semiconductor. The performance of the device can be improved obviously with double gate insulators, compared to that obtained by using a single Ta2O5 or PMMA insulator. Then, a good performance n-type OTFT, which can work at 10 V with mobility, threshold voltage and on/off current ratio of,respectively, 0.26 cm2/(V·s), 3.2 V and 8.31 × 104, was obtained. Moreover, such an OTFT shows a negligible “hysteresis effect” contributing to the hydroxyl-free insulator surface.

  11. Femtosecond dynamics of correlated many-body states in C60 fullerenes (United States)

    Usenko, Sergey; Schüler, Michael; Azima, Armin; Jakob, Markus; Lazzarino, Leslie L.; Pavlyukh, Yaroslav; Przystawik, Andreas; Drescher, Markus; Laarmann, Tim; Berakdar, Jamal


    Fullerene complexes may play a key role in the design of future molecular electronics and nanostructured devices with potential applications in light harvesting using organic solar cells. Charge and energy flow in these systems is mediated by many-body effects. We studied the structure and dynamics of laser-induced multi-electron excitations in isolated C60 by two-photon photoionization as a function of excitation wavelength using a tunable fs UV laser and developed a corresponding theoretical framework on the basis of ab initio calculations. The measured resonance line width gives direct information on the excited state lifetime. From the spectral deconvolution we derive a lower limit for purely electronic relaxation on the order of {τ }{el}={10}-3+5 fs. Energy dissipation towards nuclear degrees of freedom is studied with time-resolved techniques. The evaluation of the nonlinear autocorrelation trace gives a characteristic time constant of {τ }{vib}=400+/- 100 fs for the exponential decay. In line with the experiment, the observed transient dynamics is explained theoretically by nonadiabatic (vibronic) couplings involving the correlated electronic, the nuclear degrees of freedom (accounting for the Herzberg-Teller coupling), and their interplay.

  12. Femtosecond dynamics of correlated many-body states in C$_{60}$ fullerenes

    CERN Document Server

    Usenko, Sergey; Azima, Armin; Jakob, Markus; Lazzarino, Leslie L; Pavlyukh, Yaroslav; Przystawik, Andreas; Drescher, Markus; Laarmann, Tim; Berakdar, Jamal


    Fullerene complexes may play a key role in the design of future molecular electronics and nanostructured devices with potential applications in light harvesting using organic solar cells. Charge and energy flow in these systems is mediated by many-body effects. We studied the structure and dynamics of laser-induced multi-electron excitations in isolated C$_{60}$ by two-photon photoionization as a function of excitation wavelength using a tunable fs UV laser and developed a corresponding theoretical framework on the basis of ab initio calculations. The measured resonance line width gives direct information on the excited state lifetime. From the spectral deconvolution we derive a lower limit for purely electronic relaxation on the order of $\\tau_\\mathrm{el}=8^{+12}_{-5}$ fs. Energy dissipation towards nuclear degrees of freedom is studied in time-resolved experiments. The evaluation of the non-linear autocorrelation trace gives a characteristic time constant of $\\tau_\\mathrm{vib}=309\\pm31$ fs for the exponenti...

  13. Genetic algorithm study on the stable structures of (C60)N slusters%(C60)N团簇稳定结构的遗传算法研究

    Institute of Scientific and Technical Information of China (English)

    汪志刚; 陈耀桦; 文玉华; 朱梓忠


    采用Pacheco-Ramalho相互作用势,结合改进的遗传算法研究了(C60)N团簇(N=3~25)的稳定结构与"幻数"序列,并研究了(C60)N 团簇的势能变化.结果表明:团簇的稳定结构与构成团簇的C60分子数目有密切的关系.随着C60分子数目的增大,团簇的稳态结构呈现出由层状变为壳状,然后又转变为层状结构的变化趋势.随着组成C60分子数的增多,团簇中分子的平均势能呈下降的趋势,下降的幅度随着分子数的增大而越来越小.

  14. A theoretical study of adsorbate-adsorbate interactions on Ru(0001)

    DEFF Research Database (Denmark)

    Mortensen, Jens Jørgen; Hammer, Bjørk; Nørskov, Jens Kehlet


    Using density functional theory we study the effect of pre-adsorbed atoms on the dissociation of N(2) and the adsorption of N, N(2), and CO on Ru(0001). We have done calculations for pre-adsorbed Na, Cs, and S, and find that alkali atoms adsorbed close to a dissociating N(2) molecule will lower...... the barrier for dissociation, whereas S will increase it. The interaction with alkali atoms is mainly of an electrostatic nature. The poisoning by S is due to two kinds of repulsive interactions: a Pauli repulsion and a reduced covalent bond strength between the adsorbate and the surface d-electrons. In order...... to investigate these different interactions in more detail, we look at three different species (N atoms, and terminally bonded N(2) and CO) and use them as probes to study their interaction with two modifier atoms (Na and S). The two modifier atoms have very different properties, which allows us to decouple...

  15. Quasi-ordered C60 molecular films grown on the pseudo-ten-fold (1 0 0) surface of the Al13Co4 quasicrystalline approximant (United States)

    Fournée, V.; Gaudry, É.; Ledieu, J.; de Weerd, M.-C.; Diehl, R. D.


    The growth of C60 films on the pseudo-ten-fold (1 0 0) surface of the orthorhombic Al13Co4 quasicrystalline approximant was studied experimentally by scanning tunneling microscopy, low-energy electron diffraction and photoemission spectroscopy. The (1 0 0) surface terminates at bulk-planes presenting local atomic configurations with five-fold symmetry—similar to quasicrystalline surfaces. While the films deposited at room temperature were found disordered, high-temperature growth (up to 693 K) led to quasi-ordered molecular films templated on the substrate rectangular unit mesh. The most probable adsorption sites and geometries were investigated by density functional theory (DFT) calculations. A large range of adsorption energies was determined, influenced by both symmetry and size matching at the molecule-substrate interface. The quasi-ordered structure of the film can be explained by C60 adsorption at the strongest adsorption sites which are too far apart compared to the distance minimizing the intermolecular interactions, resulting in some disorder in the film structure at a local scale. Valence band photoemission indicates a broadening of the molecular orbitals resulting from hybridization between the substrate and overlayer electronic states. Dosing the film at temperature above 693 K led to molecular damage and formation of carbide thin films possessing no azimuthal order with respect to the substrate.

  16. 重结晶-柱色谱联用法分离C60研究%Efficient separation of fullerene C60 with the recrystallization-column chromatography method

    Institute of Scientific and Technical Information of China (English)

    刘慧敏; 彭汝芳; 金波; 楚士晋


    The paper is aimed at introducing the recrystallization-column chromatography method to the heightening of the performance of the purification between C60 and C70. We have done a series of efforts trying to separate C60 from the crude fuilerenes by means of recrystal-lization-column chromatography combined technique in our study. In proceeding with our research, the crude fuilerenes soot extract samples were first of all put into a Stoppard Erienmeyer flask with pure oxylene and then heat the whole solution to 80 ℃, while maintaining the state for four hours. Keep stirring the solution electromagnetically in the heating process, the deposit would be filtrated from the supernatant quickly with the solution kept warm. The obtained C60, could be enriched in the solid deposit by centrifugation and then sent for its purification of fuilerenes to be tested by HPLC. The purity of the said C60 obtained as a result of the sedimentation can be made to reach 90% . And, then, it is possible to let the resulted highly purified C60 be treated by column chromatography, which can then use activated carbon as a single stationary phase and toluene as the mobile phase. Under the given condition, the C60 was made dissolved with the toluene under ultrasound again. The solution gained in this case could be let to pass through the column quickly with the final purple fraction collected and concentrated by evaporation. Thus, the pure C60 can be finally obtained. The experimental results from our research indicate that high purity and total recovery with the application of this method proves to be closely related with the mass of activated carbon and the dimension of the column. When the activated carbon and fullerene mass ratio reached a ration of 9:1 with the ratio of height to diameter of the column up to 10:1, it would be possible to increase the final purity of C60 to 99.9% while the total recovering rate could reach 81 % . Compared with the simple recrystallization or column

  17. Research on double-slit diffraction experiment of C60 by a quantum mechanical approach%用量子理论方法研究C60双缝衍射

    Institute of Scientific and Technical Information of China (English)

    王海燕; 肖利; 程爽; 吴义恒; 唐厚礼; 王岩; 王清才; 张丙新



  18. Radical Addition Reaction between Perfluoro- and ω- H-Perfluorodiacyl Peroxides and C60--Synthesis of Perfluoro- and ω-H-Perfluoroalkylated C60%全氟和ω-H-全氟酰基过氧化物与C60的自由基加成反应--全氟和ω-H-全氟烷基化C60的合成

    Institute of Scientific and Technical Information of China (English)

    贺海鹰; 赵成学


    深入研究了C60与全氟酰基过氧化物的反应,通过变温EPR测试证实了此反应的自由基加成机理.用色谱分析并结合产物的19F NMR结构鉴定,首次发现由于加成过程中发生的全氟烷基自由基的β-Scission,生成了新的氟烷基自由基,从而生成了多种氟烷基化的C60.表面性能研究发现氟烷基化的C60具有优良的疏水、疏油性.总之,利用C60与全氟酰基过氧化物的反应,成功地对C60进行了全氟烷基化修饰.

  19. Dipole polarizability, structure, and stability of [2+2]-linked fullerene nanostructures (C60)n (n≤7) (United States)

    Pankratyev, Evgeniy Yu.; Tukhbatullina, Alina A.; Sabirov, Denis Sh.


    In the present work, structural features, dipole polarizability, and stability of two most promising oligomeric series (C60)n with zigzag and linear arrangement of the fullerene cages have been studied by the PBE/3ζ density functional theory method. Their mean polarizabilities and polarizability exaltations are linearly correlated with the molecular size (maximal intercage distance). Linear (C60)n have higher polarizability than zigzag oligomers with the same n. Based on the example of hexamers (C60)6, we have shown that connectivity (number of connections) has no effect on the resulting polarizability but maximal remoteness does, i.e. the geometric factor is more decisive for mean polarizability of such fullerene nanostructures. Stability of (C60)n decreases with growing molecular size for linear structures and slowly increases in the case of zigzag (C60)n. The found dependences of polarizability and stability on the molecular size may be used for assessing these parameters of larger fullerene nanostructures, hardly computable with quantum chemical methods.

  20. Electron elastic scattering and low-frequency bremsstrahlung on A@$C_{60}$: A model static approximation

    CERN Document Server

    Dolmatov, V K; Cooper, M B; Hunter, M E


    Electron elastic-scattering phase shifts and cross sections along with the differential and total cross sections and polarization of low-frequency bremsstrahlung upon low-energy electron collision with endohedral fullerenes $A$@C$_{60}$ are theoretically scrutinized versus the nature, size and spin of the encapsulated atom $A$. The case-study-atoms $A$ are N, Ar, Cr, Mn, Mo, Tc, Xe, Ba, and Eu. They are thoughtfully picked out of different rows of the periodic table. The study is performed in the framework of a model static approximation. There, both the encapsulated atom $A$ and C$_{60}$ cage are regarded as non-polarizable targets. The C$_{60}$ cage is modeled by an attractive spherical annular potential well. The study provides the most complete initial understanding of how the processes of interest might evolve upon electron collision with various $A$@C$_{60}$. Calculated results identify the most interesting and/or useful future measurements or more rigorous calculations of an electron+$A$@C$_{60}$ colli...

  1. Photoprocess of molecules encapsulated in porous solids X: Photosensitization of zeolite-Y encapsulated tris(2,2'-bipyridine-nickel-(II)ion by phenosafranine adsorbed onto the external surface of the nanoporous host

    Indian Academy of Sciences (India)

    Karuppannan Senthil Kumar; Sudha T; Paramasivam Natarajan


    Tris-(2,2'-bipyridine)-nickel-(II) complex ion encapsulated by zeolite-Y host has been synthesized by ship-in-a-bottle method. Photosensitization of nickel(II) complex (Ni(bpy)$^{2+}_{3}$) in the zeolite host by surface adsorbed phenosafranine dye was investigated by time-resolved fluorescence and absorption spectral measurements. Formation of nickel (II)-complex in the super cage of the host was ascertained by XRD, FTIR, solidstate NMR, diffuse reflectance UV-visible absorption spectroscopic techniques and ICP-OES measurements. Phenosafranine dye adsorbed on the external surface of zeolite-Y shows a decrease in fluorescence intensity with increased loading of the nickel(II) complex in zeolite-Y. Time-resolved emission studies show two excited state lifetimes for the photoexcited phenosafranine dye. Average fluorescence lifetimes of the dye in this case do not change with increase in the loading of the nickel(II) complex. However, relative contribution of short lifetime component increases when the amount of encapsulated nickel(II) complex is increased. The zeolite-Y host containing only bipyridyl ligand shows a marked decrease in fluorescence intensity. Fluorescence lifetimes of the dye however do not change with increased loading of bipyridyl while relative contribution of short lifetime component increases with an increase in the loading of bipyridyl in the host. This observation is interpreted to be due to electron transfer from the excited state of phenosafranine dye to the bipyridine. Picosecond pump-probe investigations confirm that the photoinduced electron transfer occurs from the surfaceadsorbed phenosafranine in the excited state to the nickel(II) complex within zeolite-Y cavity and also to the Ni(bpy)$^{2+}_{3}$ complex in contact with the phenosafranine dye co-adsorbed on the external surface of the host.

  2. Sputtered neutral Si nC m clusters as a monitor for carbon implantation during C 60 bombardment of silicon (United States)

    Wucher, A.; Kucher, A.; Winograd, N.; Briner, C. A.; Krantzman, K. D.


    The incorporation of carbon atoms into a silicon surface under bombardment with 40-keV C60+ ions is investigated using time-of-flight mass spectrometry of sputtered neutral and ionized Si nC m clusters. The neutral particles emitted from the surface are post-ionized by strong field infrared photoionization using a femtosecond laser system operated at a wavelength of 1400/1700 nm. From the comparison of secondary ion and neutral spectra, it is found that the secondary ion signals do not reflect the true partial sputter yields of the emitted clusters. The measured yield distribution is interpreted in terms of the accumulating carbon surface concentration with increasing C 60 fluence. The experimental results are compared with those from recent molecular dynamics simulations of C 60 bombardment of silicon.

  3. Comparative Analysis of the Antineoplastic Activity of C60 Fullerene with 5-Fluorouracil and Pyrrole Derivative In Vivo (United States)

    Lynchak, O. V.; Prylutskyy, Yu I.; Rybalchenko, V. K.; Kyzyma, O. A.; Soloviov, D.; Kostjukov, V. V.; Evstigneev, M. P.; Ritter, U.; Scharff, P.


    The antitumor activity of pristine C60 fullerene aqueous solution (C60FAS) compared to 5-fluorouracil (5-FU) and pyrrole derivative 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2.5-dione (MI-1) cytostatic drugs was investigated and analyzed in detail using the model of colorectal cancer induced by 1.2-dimethylhydrazine (DMH) in rats. The number, size, and location of the tumors were measured, and the pathology was examined. It was found that the number of tumors and total lesion area decreased significantly under the action of C60FAS and MI-1. Because these drugs have different mechanisms of action, their simultaneous administration can potentially increase the effectiveness and significantly reduce the side effects of antitumor therapy.

  4. The disorder-free non-BCS superconductor Cs3C60 emerges from an antiferromagnetic insulator parent state. (United States)

    Takabayashi, Yasuhiro; Ganin, Alexey Y; Jeglic, Peter; Arcon, Denis; Takano, Takumi; Iwasa, Yoshihiro; Ohishi, Yasuo; Takata, Masaki; Takeshita, Nao; Prassides, Kosmas; Rosseinsky, Matthew J


    The body-centered cubic A15-structured cesium fulleride Cs3C60 is not superconducting at ambient pressure and is free from disorder, unlike the well-studied face-centered cubic A3C60 alkali metal fulleride superconductors. We found that in Cs3C60, where the molecular valences are precisely assigned, the superconducting state at 38 kelvin emerges directly from a localized electron antiferromagnetic insulating state with the application of pressure. This transition maintains the threefold degeneracy of the active orbitals in both competing electronic states; it is thus a purely electronic transition to a superconducting state, with a dependence of the transition temperature on pressure-induced changes of anion packing density that is not explicable by Bardeen-Cooper-Schrieffer (BCS) theory.

  5. Communication: Quantum six-dimensional calculations of the coupled translation-rotation eigenstates of H2O@C60 (United States)

    Felker, Peter M.; Bačić, Zlatko


    We report rigorous quantum calculations of the translation-rotation (TR) eigenstates of para- and ortho-H2O@C60. They provide a comprehensive description of the dynamical behavior of H2O inside the fullerene having icosahedral (Ih) symmetry. The TR eigenstates are assigned in terms of the irreducible representations of the proper symmetry group of H2O@C60, as well as the appropriate translational and rotational quantum numbers. The coupling between the orbital and the rotational angular momenta of the caged H2O gives rise to the total angular momentum λ, which additionally labels each TR level. The calculated TR levels allow tentative assignments of a number of transitions in the recent experimental INS spectra of H2O@C60 that have not been assigned previously.

  6. The role of the C2 gas in the emergence of C60 from the condensing carbon vapour

    CERN Document Server

    Ahmad, Shoaib; Tasneem, Afshan


    A model has been developed that illustrates the emergence of C60 from the condensing carbon vapor. It is shown to depend upon the decreasing heats of formation for larger cages, exponentially increasing number of isomers for fullerenes that are larger than C60, large cages buckling induced by the pentagon-related protrusions that initiate fragmentation, the structural instability induces fragmentation that shrinks large cages and an evolving gas of C2 that is crucial to the whole process. The model describes a mechanism for the provision and presence of plenty of C2 during the formation and fragmentation processes. The bottom-up formations of large cages followed by the top-down cage shrinkage are shown to be stable, dynamical processes that lead to the C60 dominated fullerene ensemble.

  7. Black Molecular Adsorber Coatings for Spaceflight Applications (United States)

    Abraham, Nithin Susan; Hasegawa, Mark Makoto; Straka, Sharon A.


    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  8. The happy marriage between electron-phonon superconductivity and Mott physics in Cs3C60: A first-principle phase diagram (United States)

    Capone, Massimo; Nomura, Yusuke; Sakai, Shiro; Giovannetti, Gianluca; Arita, Ryotaro

    The phase diagram of doped fullerides like Cs3C60 as a function of the spacing between fullerene molecules is characterized by a first-order transition between a Mott insulator and an s-wave superconductor with a dome-shaped behavior of the critical temperature. By means of an ab-initio modeling of the bandstructure, the electron-phonon interaction and the interaction parameter and a Dynamical Mean-Field Theory solution, we reproduce the phase diagram and demonstrate that phonon superconductivity benefits from strong correlations confirming earlier model predictions. The role of correlations is manifest also in infrared measurements carried out by L. Baldassarre. The superconducting phase shares many similarities with ''exotic'' superconductors with electronic pairing, suggesting that the anomalies in the ''normal'' state, rather than the pairing glue, can be the real common element unifying a wide family of strongly correlated superconductors including cuprates and iron superconductors

  9. Regenerative adsorbent heat pump (United States)

    Jones, Jack A. (Inventor)


    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  10. Synthesis of water-soluble cystine C60 derivative with catalyst and its active oxygen radical scavenging ability

    Institute of Scientific and Technical Information of China (English)

    Wen Chao Guan; Xiang Ying Tang; Li Zhen Huang; Hong Xu


    A novel water-soluble cystine C60 derivative was synthesized in the presence of the catalyst, tetrabutylammonium hydroxide (TBAH). The product was characterized by FT-IR, UV, 1H NMR, 13C NMR, MS and elemental analysis. Furthermore, the that cystine C60 derivative showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50%inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.167 and 0.008 mg/mL, respectively.

  11. Electronic Structure and Electron-transport Properties of Peanut-shaped C_(60) Polymers with a Negative Gauss Curvature

    Institute of Scientific and Technical Information of China (English)

    J.Onoe; Y.Ochiai; T.Ito; S.Kimura; S.Ueda; Y.Noguchi; S.Ishii; K.Ohno; Y.Toda


    1 Results When a C60 film was irradiated with electron-beam (EB) with an incident energy of 3 kV, a peanut-shaped C60 polymer with metallic properties was formed[1], as shown in Fig.1. To elucidate the origin of the metallic properties of the peanut-shaped polymer, we examined the valence photoelectron spectra of the polymer using in situ high-resolution photoelectron spectroscopy and found that the electronic states of the polymer came across the Fermi level (EF)[2]. Interestingly, the spectral shape i...

  12. Enhanced performance of C60 N-type organic field-effect transistors using a pentacene passivation layer

    Institute of Scientific and Technical Information of China (English)

    Liang Xiaoyu; Cheng Xiaoman; Du Boqun; Bai Xiao; Fan Jianfeng


    We investigated the properties of C6o-based organic field-effect transistors (OFETs) with a pentacene passivation layer inserted between the C60 active layer and the gate dielectric.After modification of the pentacene passivation layer,the performance of the devices was considerably improved compared to C60-based OFETs with only a PMMA dielectric.The peak field-effect mobility was up to 1.01 cm2/(V·s) and the on/off ratio shifted to 104.This result indicates that using a pentacene passivation layer is an effective way to improve the performance of N-type OFETs.

  13. Cooperative coupling of the Li cation and groups to amplify the charge transfer between C60 and corannulene (United States)

    Sun, Gang; Xu, Jing; Chen, Zhi-Yuan; Lei, E.; Liu, Xiang-Shuai; Liu, Chun-Guang


    In present work, four complexes have been designed to investigate the effect of Li+ cation and substituent on the geometric structures and a series of electronic properties using density functional theory. The calculated results indicate that the charge decomposition (CDA) analysis and extend charge decomposition analysis (ECDA) of four complexes have the same sequence. The average d values defined the distances between C60 and corannulene display the inverse sequence. Consequently, the cooperative coupling of the Li+ cation and appropriate substituent is predicted to be an effective way to enhance the charge transfer between the C60 and corannulene derivatives.

  14. Improved photovoltaic performance of heterostructured tetrapod-shaped CdSe/CdTe nanocrystals using C60 interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanqin; Mastria, Rosanna; Fiore, Angela; Nobile, Concetta; Yin, Lunxiang; Cheng, Gang; Cingolani, Roberto; Manna, Liberato; Gigli, Giuseppe [National Nanotechnology Lab of CNR-INFM (NNL), University of Salento, Lecce (Italy); Biasiucci, Mariano [National Nanotechnology Lab of CNR-INFM (NNL), University of Salento, Lecce (Italy); Physical Department, University of Salerno, Baronissi (Italy); Cucolo, Anna Maria [Physical Department, University of Salerno, Baronissi (Italy)


    Photovoltaic (PV) devices based on CdSe/CdTe-C60 active layers, in which the nanocrystal and fullerene (C60) layers work as electron-donor and electron-acceptor/transport layers, respectively, were fabricated. Efficiencies up to 0.62% were reached in the hybrid cells. The PV performance was greatly improved with respect to that of CdSe/CdTe-P3HT- and CdSe/CdTe-based devices, fabricated as reference. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  15. On the polarity of buckminsterfullerene with a water molecule inside

    NARCIS (Netherlands)

    Ensing, B.; Costanzo, F.; Silvestrelli, P.L.


    Since the recent achievement of Kurotobi and Murata to capture a water molecule in a C60 fullerene (Science2011, 333, 613), there has been a debate about the properties of this H2O@C60 complex. In particular, the polarity of the complex, which is thought to be underlying the easy separation of H2O@C

  16. MOLECULAR IMPRINTED POLYMERS--Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; XU Mancai; SHI Zuoqing; HE Binglin


    Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  17. 氟金云母衬底上C60薄膜的光学性质%Optical Properties of C60 Thin Films Deposited on Fluorophlogopite Substrates

    Institute of Scientific and Technical Information of China (English)

    邹云娟; 张兴旺; 宋雪梅; 严辉; 陈光华


    用热壁外延法在氟金云母衬底上生长出了高质量C60薄膜,用原子力显微镜观察了样品的表面形貌.测量并分析了不同厚度C60薄膜的紫外-可见吸收光谱.由测量的透射及反射光谱,经计算得到了吸收系数与入射光子能量的关系.利用结晶半导体的带间跃迁理论,对禁戒的带间直接跃迁hu→t1u和电偶极允许的带间直接跃迁hu→t1g的带隙分别进行了计算.%High quality C60 thin films are deposited on fluorophlogopite substrates by hot-wall epitaxy method.The surface crystal morphology of C60 thin films is observed under an atomic force microscopy.The UV-Vis absorption spectra of C60 thin films with different film thickness are analyzed, and the absorption coefficient α is calculated from the measured transmittance and the reflection spectra.Based on the interband transition theory of semiconductor, the values of hu→t1u (dipole-forbidden) and hu→t1g (dipole-allowed) optical band gaps are obtained from the analysis of the corresponding absorption coefficient α.

  18. Adsorption behavior of 5-fluorouracil on pristine, B-, Si-, and Al-doped C60 fullerenes: A first-principles study (United States)

    Hazrati, Mehrnoosh Khodam; Hadipour, Nasser L.


    Since C60 fullerene has been enormously studied as a drug delivery vehicle, we investigated the interaction between C60 and 5-fluorouracil drug using density functional theory calculations. The electronic and structural properties were explored in terms of binding energies, frontier molecular orbitals, DOS and NBO. To manipulate 5-fluorouracil adsorption properties on the C60, we substituted a carbon atom with boron, silicon and aluminum. In contrast to the pristine C60, the binding energy of 5-fluorouracil to the doped fullerenes is much more negative and the HOMO-LUMO gaps are significantly enlarged. Our results suggest that doping may improve C60 drug delivery properties.

  19. Models and Simulations of C60-Fullerene Plasma Jets for Disruption Mitigation and Magneto-Inertial Fusion (United States)

    Bogatu, Ioan-Niculae; Galkin, Sergei A.; Kim, Jin-Soo


    We present the models and simulation results of C60-fullerene plasma jets proposed to be used for the disruption mitigation on ITER and for magneto-inertial fusion (MIF). The model describing the fast production of a large mass of C60 molecular gas in the pulsed power source by explosive sublimation of C60 micro-grains is detailed. Several aspects of the magnetic ``piston'' model and the 2D interchange (magnetic Rayleigh-Taylor) instability in the rail gun arc dynamics are described. A plasma jet adiabatic expansion model is used to investigate the in-flight three-body recombination during jet transport to the plasma boundary. Our LSP PIC code 3D simulations show that heavy C60 plasmoid penetrates deeply through a transverse magnetic barrier demonstrating self-polarization and magnetic field expulsion effects. The LSP code 3D simulation of two plasma jets head-on injection along a magnetic field lines for MIF are also discussed.

  20. Low band gap and ionic bonding with charge transfer, threshold in the polymeric lithium fulleride Li(4)C(60)

    NARCIS (Netherlands)

    Macovez, Roberto; Savage, Rebecca; Schiessling, Joachim; Kamaras, Katalin; Rudolf, Petra; Venema, L.C.


    We demonstrate the growth of crystalline Li(4)C(60) films. The low-energy electron diffraction pattern of the films indicates the formation of polymer chains in the plane of the surface, consistent with the reported crystal structure. Electron energy loss and photoemission spectra identify the Li(4)

  1. An elusive fulvene 1,7,11,24-C60(CF3)4 and its unusual reactivity. (United States)

    Whitaker, James B; Kuvychko, Igor V; Shustova, Natalia B; Chen, Yu-Sheng; Strauss, Steven H; Boltalina, Olga V


    The X-ray crystal structure of a trifluoromethylfullerene (TMF), 1,7,11,24-C60(CF3)4, is reported for the first time. This elusive intermediate, while highly air stable as a solid, exhibits highly regioselective reactivity towards molecular oxygen in polar solvents, and only when exposed to light.

  2. Gas Phase Absorption Spectroscopy of C+60 and C+70 in a Cryogenic Ion Trap: Comparison with Astronomical Measurements (United States)

    Campbell, E. K.; Holz, M.; Maier, J. P.; Gerlich, D.; Walker, G. A. H.; Bohlender, D.


    Recent low-temperature laboratory measurements and astronomical observations have proved that the fullerene cation {{{C}}}60+ is responsible for four diffuse interstellar bands (DIBs). These absorptions correspond to the strongest bands of the lowest electronic transition. The gas phase spectrum below 10 {{K}} is reported here for the full wavelength range encompassed by the electronic transition. The absorption spectrum of {{{C}}}70+, with its origin band at 7959.2 {{\\mathringA }}, has been obtained under similar laboratory conditions. Observations made toward the reddened star {HD} 183143 were used in a specific search for the absorption of these fullerene cations in diffuse clouds. In the case of {{{C}}}60+, one further band in the astronomical spectrum at 9348.5 \\mathringA is identified, increasing the total number of assigned DIBs to five. Numerous other {{{C}}}60+ absorptions in the laboratory spectrum are found to lie below the astronomical detection limit. Special emphasis is placed on the laboratory determination of absolute absorption cross-sections. For {{{C}}}60+ this directly yields a column density, N({{{C}}}60+), of 2× {10}13 {{{cm}}}-2 in diffuse clouds, without the need to rely on theoretical oscillator strengths. The intensity of the {{{C}}}70+ electronic transition in the range 7000-8000 Å is spread over many features of similar strength. Absorption cross-section measurements indicate that even for a similar column density, the individual absorption bands of {{{C}}}70+ will be too weak to be detected in the astronomical spectra, which is confirmed giving an upper limit of 2 {{m\\mathringA }} to the equivalent width. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

  3. Development of C60-based labeling reagents for the determination of low-molecular-weight compounds by matrix assisted laser desorption ionization mass (I): Determination of amino acids in microliter biofluids. (United States)

    Wu, Pin; Xiao, Hua-Ming; Ding, Jun; Deng, Qian-Yun; Zheng, Fang; Feng, Yu-Qi


    Quantification of low molecular weight compounds (<800 Da) using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS) is challenging due to the matrix signal interference at low m/z region and poor reproducibility of MS responses. In this study, a C60 labeling-MALDI MS strategy was proposed for the fast, sensitive and reliable determination of amino acids (AAs) in biofluids. An N-hydroxysuccinimide functionalized C60 was synthesized as the labeling reagent and added as an 880 Da tag to AAs; a carboxyl acid containing C60 was employed as the internal standards to normalize MS variations. This solved the inherent problems of MALDI MS for small molecule analysis. The entire analytical procedure-which consisted of simple protein precipitation and 10 min of derivatization in a microwave prior to the MALDI MS analysis-could be accomplished within 20 min with high throughput and great sample matrix tolerance. AA quantification showed good linearity from 0.7 to 70.0 μM with correlation coefficients (R) larger than 0.9954. The limits of detection were 70.0-300.0 fmol. Good reproducibility and reliability of the method were demonstrated by intra-day and inter-day precision with relative standard deviations less than 13.8%, and the recovery in biofluid ranged from 80.4% to 106.8%. This approach could be used in 1 μL of urine, serum, plasma, whole blood, and cerebrospinal fluid. Most importantly, the C60 labeling strategy is a universal approach for MALDI MS analysis of various LMW compounds because functionalized C60 is now available on demand.

  4. Attributing Effects of Aqueous C60 Nano-Aggregates to Tetrahydrofuran Decomposition Products in Larval Zebrafish by Assessment of Gene Expression (United States)

    Henry, Theodore B.; Menn, Fu-Min; Fleming, James T.; Wilgus, John; Compton, Robert N.; Sayler, Gary S.


    Background C60 is a highly insoluble nanoparticle that can form colloidal suspended aggregates in water, which may lead to environmental exposure in aquatic organisms. Previous research has indicated toxicity from C60 aggregate; however, effects could be because of tetrahydrofuran (THF) vehicle used to prepare aggregates. Objective Our goal was to investigate changes in survival and gene expression in larval zebrafish Danio rerio after exposure to aggregates of C60 prepared by two methods: a) stirring and sonication of C60 in water (C60–water); and b) suspension of C60 in THF followed by rotovaping, resuspension in water, and sparging with nitrogen gas (THF–C60). Results Survival of larval zebrafish was reduced in THF–C60 and THF–water but not in C60–water. The greatest differences in gene expression were observed in fish exposed to THF–C60 and most (182) of these genes were similarly expressed in fish exposed to THF–water. Significant up-regulation (3- to 7-fold) of genes involved in controlling oxidative damage was observed after exposure to THF–C60 and THF–water. Analyses of THF–C60 and THF–water by gas chromatography–mass spectrometry did not detect THF but found THF oxidation products γ-butyrolactone and tetrahydro-2-furanol. Toxicity of γ-butyrolactone (72-hr lethal concentration predicted to kill 50% was 47 ppm) indicated effects in THF treatments can result from γ-butyrolactone toxicity. Conclusion This research is the first to link toxic effects directly to a THF degradation product (γ-butyrolactone) rather than to C60 and may explain toxicity attributed to C60 in other investigations. The present work was first presented at the meeting “Overcoming Obstacles to Effective Research Design in Nanotoxicology” held 24–26 April 2006 in Cambridge, Massachusetts, USA. PMID:17637923

  5. Radiosensitization by fullerene-C60 dissolved in squalene on human malignant melanoma through lipid peroxidation and enhanced mitochondrial membrane potential (United States)

    Kato, Shinya; Kimura, Masatsugu; Miwa, Nobuhiko


    We examined fullerene-C60 dissolved in squalene (C60/Sqe) for the ability to potentiate the radiosensitization under X-ray irradiation on human malignant melanoma HMV-II cells, which were treated with C60/Sqe and thereafter irradiated with X-ray. The cell proliferation for C60/Sqe was inhibited more markedly than for Sqe alone. Meanwhile, cell proliferation was almost unaltered for C60/squalane (Sqa) or Sqa, a hydrogenated form of Sqe, as compared to no-additive control. Thus radiosensitization of C60/Sqe is attributed to peroxidation of unsaturated bonds of squalene by X-ray-excited C60 in contrast to squalane. The fluorescence images of HMV-II cells stained with Rhodamine123, an indicator for mitochondrial membrane potential, were monitored for 6 h after X-ray irradiation. C60/Sqe obviously exhibited more augmented fluorescence intensity on perinuclear region of HMV-II cells than Sqe alone. TBARS assay showed that the lipid peroxidation level as malondialdehyde-equivalent increased by combination of C60/Sqe and X-ray dose-dependently on X-ray doses. C60/Sqe exhibited lipid peroxidation more markedly by 1.2-fold than Sqe alone. Thus the level of lipid peroxidation of squalene was sufficiently higher in C60/Sqe than in Sqe in the absence of C60 under X-ray irradiation, suggesting the combination of C60/Sqe and X-ray irradiation induced radiosensitization on HMV-II cells by peroxidation of absorbed Sqe in mitochondrial membrane via oxidative stress mediated by fullerene-C60.

  6. Electronic structure of benzene adsorbed on Ni and Cu surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Weinelt, M.; Nilsson, A.; Wassdahl, N. [Uppsala Univ. (Sweden)] [and others


    Benzene has for a long time served as a prototype adsorption system of large molecules. It adsorbs with the molecular plane parallel to the surface. The bonding of benzene to a transition metal is typically viewed to involve the {pi} system. Benzene adsorbs weakly on Cu and strongly on Ni. It is interesting to study how the adsorption strength is reflected in the electronic structure of the adsorbate-substrate complex. The authors have used X-ray Emission (XE) and X-ray Absorption (XA) spectroscopies to selectively study the electronic states localized on the adsorbed benzene molecule. Using XES the occupied states can be studies and with XAS the unoccupied states. The authors have used beamline 8.0 and the Swedish endstation equipped with a grazing incidence x-ray spectrometer and a partial yield absorption detector. The resolution in the XES and XAS were 0.5 eV and 0.05 eV, respectively.

  7. 支持向量机算法用于C60溶解度的研究%Application of Algorithm of Support Vector Machine for Study on the Solubility of C60

    Institute of Scientific and Technical Information of China (English)

    毕韶丹; 张向东; 关宏宇



  8. Effect of Diels-Alder Reaction in C60-Tetracene Photovoltaic Devices. (United States)

    Proudian, Andrew P; Jaskot, Matthew B; Lyiza, Christelle; Diercks, David R; Gorman, Brian P; Zimmerman, Jeramy D


    Developing organic photovoltaic materials systems requires a detailed understanding of the heterojunction interface, as it is the foundation for photovoltaic device performance. The bilayer fullerene/acene system is one of the most studied models for testing our understanding of this interface. We demonstrate that the fullerene and acene molecules chemically react at the heterojunction interface, creating a partial monolayer of a Diels-Alder cycloadduct species. Furthermore, we show that the reaction occurs during standard deposition conditions and that thermal annealing increases the concentration of the cycloadduct. The cycloaddition reaction reduces the number of sites available at the interface for charge transfer exciton recombination and decreases the charge transfer state reorganization energy, increasing the open circuit voltage. The submonolayer quantity of the cycloadduct renders it difficult to identify with conventional characterization techniques; we use atom probe tomography to overcome this limitation while also measuring the spatial distribution of each chemical species.

  9. Reduced working electrode based on fullerene C60 nanotubes-DNA: Characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xuzhi [Key Laboratory of Eco-Chemical Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, No. 106, Nanjing Road, Qingdao 266071, Shandong (China); Qu Yongtao [Key Laboratory of Rubber-plastics of Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Piao Guangzhe, E-mail: [Key Laboratory of Rubber-plastics of Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhao Jian [Key Laboratory of Rubber-plastics of Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Jiao Kui, E-mail: [Key Laboratory of Eco-Chemical Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)


    Fullerene C{sub 60} nanotubes (FNTs) were functionalized with sequence-specific single-stranded DNA to form a kind of complexes (FNT-DNA), which could be brought efficiently into aqueous solution. The dispersed FNT-DNA could form a layer of stable film on the surface of glassy carbon electrode (GCE). In the Britton-Robinson buffer solution of pH {>=}7.0, the FNT-DNA modified on the GCE presented an irreversible two-step six-electron transfer reduction reaction. The reduced modified electrode had a rather wide electrochemical window and could be used as a functionalized working electrode, which showed a good enrichment capability towards the positively charged molecules. The selective detection of dopamine in the presence of a high amount of ascorbic acid could be realized at the reduced FNT-DNA-modified GCE in neutral buffer solution.

  10. Synthesis of cystine C60 derivative and its protective effects on hydrogen peroxide-induced apoptosis in PC12 cells

    Institute of Scientific and Technical Information of China (English)

    Zhen Hu; Hai Ping Xing; Zhou Zhu; Wei Wang; Wen Chao Guan


    Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities, especially prominent in neural diseases. One of the usable ways to prevent the reactive oxygen species (ROS)-mediated cellular injury is dietary or pharmaceutical augmentation of some free radical scavenger. Water-soluble amino-fullerene is a novel compound that behaves as a free radical scavenger with excellent biology consistent. In the present study, we have synthesized and characterized a novel cystine C60 derivative for the first time, and investigated the effects on hydrogen peroxide-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. PC12 cells treated with hydrogen peroxide underwent apoptotic death as determined by MTT, PI/Hoechst 33342 staining and flow cytometry analysis. These results suggested that cystine C60 derivative has the potential to prevent oxidative stress-induced cell death and has no evident toxicity.

  11. The effect of angle of incidence to low damage sputtering of organic polymers using a C 60 ion beam (United States)

    Miyayama, Takuya; Sanada, Noriaki; Iida, Shin-ichi; Hammond, John S.; Suzuki, Mineharu


    The effect of angle of incidence of C 60 ion beam for low damage polymer depth profiling on TOF-SIMS and XPS has been investigated. In this study, TOF-SIMS and XPS depth profiles were taken at several angles of incidence of C 60 ion beam and the results were compared with each other. By using a higher angle of incidence, in XPS analysis, the changes of atomic concentration for polyethyleneterephthalate (PET) were suppressed. In TOF-SIMS analysis, the degradations of fragment ion intensity for PET and polystyrene (PS) were also suppressed at a higher angle of incidence. Although the information depth of TOF-SIMS is different from that of XPS, both results suggested that a higher angle of incidence is a better condition for low damage polymer depth profiling.

  12. Enhanced performance of C60 organic field effect transistors using a tris(8-hydroxyquinoline) aluminum buffer layer

    Institute of Scientific and Technical Information of China (English)

    Zheng Hong; Cheng Xiaoman; Tian Haijun; Zhao Geng


    We have investigated the properties of C60-based organic field effect transistors (OFETs) with a tris(8-hydroxyquinoline) aluminum (Alq3) buffer layer inserted between the source/drain electrodes and the active material.The electrical characteristics of OFETs are improved with the insertion of Aiq3 film.The peak field effect mobility is increased to 1.28 × 10-2 cm2/(V.s) and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm.The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films.

  13. On the possibility of the electron polarization to be the driving force for the C60-TMB nanowire growth

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Geng, Junfeng; Solov'yov, Andrey V.;


    The effect of electron polarization has been suggested to explain the exceptionally large length-to width aspect ratio (more than 3000) in recently observed C_60-based nanowires. The theoretical estimates performed in the present Letter show that at room temperature the effect of electron...... polarization is negligibly small and, therefore, cannot become the driving force for nanowire growth along one preferential direction. Experimental measurements are in agreement with the theoretical analysis: the nanowires have been observed to emerge from the polar 1,2,4-trimethylbenzene and non-polar 1......,3,5-trimethylbenzene solution of C_60, while no nanowires from polar toluene, 1,2,3-trimethylbenzene and non-polar benzene solutions could be recorded....

  14. Endohedral metallofullerenes, M@C60 (M = Ca, Na, Sr): selective adsorption and sensing of open-shell NOx gases. (United States)

    Tawfik, Sherif Abdulkader; Cui, X Y; Ringer, S P; Stampfl, C


    Based on density-functional theory and non-equilibrium Green's function calculations, we demonstrate that endohedral metallofullerenes (EMFs) are reactive to open-shell gases, and therefore have the potential application as selective open-shell gas sensors. The adsorption of eight gas species (CO, H2O, H2S, NO2, NO, SO2, O2 and NH3) on three EMFs (M@C60, M = Ca, Na and Sr) shows that the adsorption energies of the EMFs towards NO2 and NO are significantly higher than the closed-shell species. Moreover, the high selectivity appears relatively insensitive to the inserted metal atoms. The calculated current-voltage characteristics of gold-M@C60-gold structures (M = Ca, Na) show that the adsorption of NO2 leads to significant change in conductivity, suggesting a potential application as an EMF gas resistive sensing device.

  15. Robust Inclusion Complexes of Crown Ether Fused Tetrathiafulvalenes with Li+@C-60 to Afford Efficient Photodriven Charge Separation

    DEFF Research Database (Denmark)

    Supur, M.; Kawashima, Y.; Larsen, K. R.;


    ) obtained by UV/Vis titrations in benzonitrile (PhCN) at room temperature. On the basis of DFT studies at the B3LYP/6-311G(d,p) level, the orbital interactions between the crown ether moieties and the p surface of the fullerene together with the endohedral Li+ have a crucial role in robust complex formation...... for 1 center dot Li+@C-60 and 2 center dot Li+@C-60, respectively, and quantum yields of 0.82 in PhCN have been observed by utilizing time-resolved transient absorption spectroscopy and then confirmed by electron paramagnetic resonance measurements at 4 K. The difference in crown ether structures...

  16. Surface-enhanced fluorescence and surface-enhanced Raman scattering of push-pull molecules: sulfur-functionalized 4-amino-7-nitrobenzofurazan adsorbed on Ag and Au nanostructured substrates. (United States)

    Muniz-Miranda, Maurizio; Del Rosso, Tommaso; Giorgetti, Emilia; Margheri, Giancarlo; Ghini, Giacomo; Cicchi, Stefano


    We investigated the chemisorption of self-assembled monolayers of sulfur-functionalized 4-amino-7-nitrobenzofurazan on gold and silver nanoisland films (NIFs) by means of surface-enhanced fluorescence (SEF) and surface-enhanced Raman scattering (SERS). The ligand is a push-pull molecule, where an intramolecular charge transfer occurs between an electron-donor and an electron-acceptor group, thus exhibiting nonlinear optical properties that are related to both SERS and SEF effects. The presence of different heteroatoms in the molecule ensures the possibility of chemical interaction with both silver and gold substrates. The SERS spectra suggest that furazan is bound to silver via lone pairs of the nitrogen atoms, whereas the ligand is linked to gold via a sulfur atom. Silver NIFs provide more efficient enhancement of both fluorescence and Raman scattering in comparison with gold NIFs. The present SEF and SERS investigation could provide useful information for foreseeing changes in the nonlinear responses of this push-pull molecule.

  17. Growth of Fullerene Fragments Using the Diels-Alder Cycloaddition Reaction: First Step towards a C60 Synthesis by Dimerization

    Directory of Open Access Journals (Sweden)

    Julio A. Alonso


    Full Text Available Density Functional Theory has been used to model the Diels-Alder reactions of the fullerene fragments triindenetriphenilene and pentacyclopentacorannulene with ethylene and 1,3-butadiene. The purpose is to prove the feasibility of using Diels-Alder cycloaddition reactions to grow fullerene fragments step by step, and to dimerize fullerene fragments, as a way to obtain C60. The dienophile character of the fullerene fragments is dominant, and the reaction of butadiene with pentacyclopentacorannulene is favored.

  18. Synthesis and NMR Spectral Studies of the 7-C60-Adduct of N,N-(Tetrachlorophthaloyl Dehydroabietylamine

    Directory of Open Access Journals (Sweden)

    Zhi Zhou


    Full Text Available The 7-C60-adduct of N,N-(tetrachlorophthaloyldehydroabietylamine was synthesized for the first time and characterized by IR, UV-vis, mass and NMR spectral studies. The 1H-NMR and 13C-NMR resonance signals of the new compound are unambiguously assigned by using homo- and heteronuclear 2D NMR spectroscopic techniques such as COSY, ROESY, HSQC and HMBC. The C1 symmetric structure with 6,6-junction of compound was determined.

  19. First-principles investigation of quantum transport through an endohedral N@C60 in the Coulomb blockade regime. (United States)

    Yu, Zhizhou; Chen, Jian; Zhang, Lei; Wang, Jian


    We report an investigation of Coulomb blockade transport through an endohedral N@C60 weakly coupled with aluminum leads, employing the first-principles method combined with the Keldysh non-equilibrium Green's function derived from the equation of motion beyond the Hartree-Fock approximation. The differential conductance characteristics of the molecular device are calculated within the Coulomb blockade regime, which shows the Coulomb diamond as observed experimentally. When the gate voltage is less than that of the degeneracy point, there are two peaks in the differential conductance with an excited state induced by the change of the exchange interaction between the spin of C60 and the encapsulated nitrogen atom due to the transition from N@C(1-)(60) to N@C(2-)(60), while for a gate voltage larger than that of the degeneracy point, no excited state is available due to the quenching of exchange energy. As a result, there is only one Coulomb blockade peak in the differential conductance from the electron tunneling through the highest energy level below the Fermi level. Our first-principles results are in good agreement with experimental data obtained by an endohedral N@C60 molecular device.


    Directory of Open Access Journals (Sweden)

    G. B. Skamrova


    Full Text Available Now the number of physical and chemical biologically active damage factors dramatically increased. The ways to neutralize such effects have not been studied enough. In this work the techniques of visual assessment of chromatin granulation and of electronegativity of human buccal epithelium cell nuclei were used in order to study the combined effects of the exposure to low-intensity electromagnetic radiation of the millimeter range electromagnetic radiation and to the DNA-binding compounds, such as: antibiotic doxorubicin, mutagens ethidium bromide and proflavine, as well as to caffeine and C60 -fullerene which are not directly interact with DNA. When the action of electromagnetic radiation and DNA-binding compounds is combined, a synergistic effect of reducing the cell response was observed in contrast to the effects caused by electromagnetic radiation and drugs separately. When cells were irradiated in the presence of C60 -fullerene or caffeine, a protective effect of compounds against electromagnetic radiation influence was observed. The obtained results may provide perspectives in the use of the C60 fullerene and caffeine as DNA-protectors under the action of electromagnetic radiation.

  1. Oxidatively damaged DNA in rats exposed by oral gavage to C60 fullerenes and single-walled carbon nanotubes

    DEFF Research Database (Denmark)

    Folkmann, Janne K; Risom, Lotte; Jacobsen, Nicklas R


    BACKGROUND: C60 fullerenes and single-walled carbon nanotubes (SWCNT) are projected to be used in medicine and consumer products with potential human exposure. The hazardous effects of these particles are expected to involve oxidative stress with generation of oxidatively damaged DNA that might...... be the initiating event in the development of cancer. OBJECTIVE: In this study we investigated the effect of a single oral administration of C60 fullerenes and SWCNT. METHODS: We measured the level of oxidative damage to DNA as the premutagenic 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in the colon mucosa...... the levels of 8-oxodG in liver and lung. Administration of C60 fullerenes increased the hepatic level of 8-oxodG, whereas only the high dose generated 8-oxodG in the lung. We detected no effects on 8-oxodG in colon mucosa. Suspension of particles in saline solution or corn oil yielded a similar extent...

  2. Properties of K,Rb-intercalated C60 encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

    KAUST Repository

    Mahfouz, R.


    We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C60 encapsulated inside carbon nanotubes called peapods can be derived from 13C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T1) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C60 that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C60 at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(EF).

  3. Equilibrium molecular theory of two-dimensional adsorbate drops on surfaces of heterogeneous adsorbents (United States)

    Tovbin, Yu. K.


    A molecular statistical theory for calculating the linear tension of small multicomponent droplets in two-dimensional adsorption systems is developed. The theory describes discrete distributions of molecules in space (on a scale comparable to molecular size) and continuous distributions of molecules (at short distances inside cells) in their translational and vibrational motions. Pair intermolecular interaction potentials (the Mie type potential) in several coordination spheres are considered. For simplicity, it is assumed that distinctions in the sizes of mixture components are slight and comparable to the sizes of adsorbent adsorption centers. Expressions for the pressure tensor components inside small droplets on the heterogeneous surface of an adsorbent are obtained, allowing calculations of the thermodynamic characteristics of a vapor-fluid interface, including linear tension. Problems in refining the molecular theory are discussed: describing the properties of small droplets using a coordination model of their structure, considering the effect an adsorbate has on the state of a near-surface adsorbent region, and the surface heterogeneity factor in the conditions for the formation of droplets.

  4. Zeolites as alcohol adsorbents from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Cekova Blagica


    Full Text Available The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.

  5. Electronic properties of NH4-adsorbed graphene nanoribbon as a promising candidate for a gas sensor (United States)

    Harada, Naoki; Sato, Shintaro


    The electronic properties of NH4-adsorbed N = 7 armchair graphene nanoribbons (AGNRs) were theoretically investigated using self-consistent atomistic simulations to explore the feasibility of AGNRs as a gas sensing material. Whereas a pristine AGNR has a finite band gap and is an intrinsic semiconductor, an NH4-adsorbed AGNR exhibits heavily doped n-type properties similar to a graphene sheet with the molecules adsorbed. The electric characteristics of a back-gated AGNR gas sensor were also simulated and the drain current changed exponentially with increasing number of adsorbed molecules. We may conclude that an AGNR is promising as a highly sensitive gas-sensing material with large outputs.

  6. VUV reflection spectrum of C60 compacted powder%C60粉末压片的同步辐射真空紫外反射光谱

    Institute of Scientific and Technical Information of China (English)

    姬秉正; 周映雪; 孙润光; 张新夷


    利用同步辐射光源,测量了C60粉末压片在50~250 nm波长范围内的真空紫外(UVU)反射光谱,并依据Kramers-Kronig关系,计算出吸收光谱.获得的10个吸收峰,均与等离子体的元激发和从价带向π*或σ*带的不同带间跃迁有关.

  7. Photophysical Properties and Photoinduced Electron Transfer between[60]Fullerene—containing Cyclic Sulphoxide [C60C60H8SO]and Tetrathiafulvalene(TTF) by Laser Flash Photolysis

    Institute of Scientific and Technical Information of China (English)



    Photoinduced electron transfer(PET) processes between C60-C6H8SO and Tetrathiafulvalene(TTF) have been studied by nanosecond laser photolysis.Quantrm yiekds(φet) and rate constants of electron transfer(ket) from TTF to excited triplet state of[60] fullerene-containing cyclic sulphoxide in benzonitrile(BN) have been evaluated by observing the transient absorption bands in the NIR region.With the decay of excited triplet state of [60]fullerene-containing cyclic suplhoxide,the rise of radical anion of [60]fullerene-containing cyclic sulphoxinde is observed.

  8. High performance Mo adsorbent PZC

    Energy Technology Data Exchange (ETDEWEB)



    We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

  9. A Computational Study of the Interaction and Polarization Effects of Complexes Involving Molecular Graphene and C60 or a Nucleobases. (United States)

    Avramopoulos, Aggelos; Otero, Nicolás; Karamanis, Panaghiotis; Pouchan, Claude; Papadopoulos, Manthos G


    A systematic analysis of the molecular structure, energetics, electronic (hyper)polarizabilities and their interaction-induced counterparts of C60 with a series of molecular graphene (MG) models, CmHn, where m = 24, 84, 114, 222, 366, 546 and n = 12, 24, 30, 42, 54, 66, was performed. All the reported data were computed by employing density functional theory and a series of basis sets. The main goal of the study is to investigate how alteration of the size of the MG model affects the strength of the interaction, charge rearrangement, and polarization and interaction-induced polarization of the complex, C60-MG. A Hirshfeld-based scheme has been employed in order to provide information on the intrinsic polarizability density representations of the reported complexes. It was found that the interaction energy increases approaching a limit of -26.98 kcal/mol for m = 366 and 546; the polarizability and second hyperpolarizability increase with increasing the size of MG. An opposite trend was observed for the dipole moment. Interestingly, the variation of the first hyperpolarizability is relatively small with m. Since polarizability is a key factor for the stability of molecular graphene with nucleobases (NB), a study of the magnitude of the interaction-induced polarizability of C84H24-NB complexes is also reported, aiming to reveal changes of its magnitude with the type of NB. The binding strength of C84H24-NB complexes is also computed and found to be in agreement with available theoretical and experimental data. The interaction involved in C60 B12N12H24-NB complexes has also been considered, featuring the effect of contamination on the binding strength between MG and NBs.

  10. Photocatalytic Degradation of Rhodamine B Dye with MWCNT/TiO2/C60 Composites by a Hydrothermal Method

    Institute of Scientific and Technical Information of China (English)

    SHI Xiaoliang; YANG Xingyong; WANG Shuwei; WANG Sheng; ZHANG Qiaoxin; WANG Yufu


    Multi-walled carbon nanotube (MWCNT)/TiO2/C60 composite catalysts were prepared by hydrothermal method. TiO2 was deposited on the MWCNT surface. Their photocatalytic activities for degradation of Rhodamine B dye were studied. X-ray diffraction, field emission transmission electron microscopy, ultraviolet-visible light absorption spectrum and photoluminescence spectrum were carried out to characterize the composite catalysts. The results indicated that MWCNTs and C6o could greatly enhance the photocatalytic activity of TiO2.

  11. Compression of Carbon Nanotubes Filled with C60, CH4, or Ne: Predictions from Molecular Dynamics Simulations (United States)

    Ni, Boris; Sinnott, Susan B.; Mikulski, Paul T.; Harrison, Judith A.


    The effect of filling nanotubes with C60, CH4, or Ne on the mechanical properties of the nanotubes is examined. The approach is classical molecular dynamics using the reactive empirical bond order (REBO) and the adaptive intermolecular REBO potentials. The simulations predict that the buckling force of filled nanotubes can be larger than that of empty nanotubes, and the magnitude of the increase depends on the density of the filling material. In addition, these simulations demonstrate that the buckling force of empty nanotubes depends on temperature. Filling the nanotube disrupts this temperature effect so that it is no longer present in some cases.

  12. Strongly Enhanced Current-Carrying Performance in MgB2 Tape Conductors by Novel C60 Doping


    Zhang, Xianping; Ma, Yanwei; Gao, Zhaoshun; Wang, Dongliang; Wang, Lei; Liu, Wei; Wang, Chunru


    MgB2 is a promising superconductor for important large-scale applications for both high field magnets and cryocooler-cooled magnet operated at temperatures around 20 K. In this work, by utilizing C60 as a viable alternative dopant, we demonstrate a simple and industrially scaleable rout that yields a 10-15-fold improvement in the in-high-field current densities of MgB2 tape conductors. For example, a Jc value higher than 4x10^4 A/cm^2 (4.2 K, 10 T), which exceeds that for NbTi superconductor,...

  13. Energy loss spectroscopy of Buckminster C60 with twisted electrons: Influence of orbital angular momentum transfer on plasmon generation

    CERN Document Server

    Schüler, M


    Recent experimental progress in creating and controlling singular electron beams that carry orbital angular momentum allows for new types of local spectroscopies. We theoretically investigate the twisted-electron energy loss spectroscopy (EELS) from the C60 fullerene. Of particular interest are the strong multipolar collective excitations and their selective response to the orbital angular momentum of the impinging electron beam. Based on ab-initio calculations for the collective response we compute EELS signals with twisted electron beams and uncover the interplay between the plasmon polarity and the amount of angular momentum transfer.

  14. Progress in Development of C60 Nanoparticle Plasma Jet for Diagnostic of Runaway Electron Beam-Plasma Interaction and Disruption Mitigation Study for ITER (United States)

    Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.


    We produced a C60 nanoparticle plasma jet (NPPJ) with uniquely fast response-to-delivery time (~ 1 - 2 ms) and unprecedentedly high momentum (~ 0 . 6 g .km/s). The C60 NPPJ was obtained by using a solid state TiH2/C60 pulsed power cartridge producing ~180 mg of C60 molecular gas by sublimation and by electromagnetic acceleration of the C60 plasma in a coaxial gun (~35 cm length, 96 kJ energy) with the output of a high-density (>1023 m-3) hyper-velocity (>4 km/s) plasma jet. The ~ 75 mg C60/C plasma jet has the potential to rapidly and deeply deliver enough mass to significantly increase electron density (to ne ~ 2 . 4 ×1021 m-3, i.e. ~ 60 times larger than typical DIII-D pre-disruption value, ne 0 ~ 4 ×1019 m-3), and to modify the 'critical electric field' and the runaway electrons (REs) collisional drag during different phases of REs dynamics. The C60 NPPJ, as a novel injection technique, allows RE beam-plasma interaction diagnostic by quantitative spectroscopy of C ions visible/UV line intensity. The system is scalable to ~ 1 - 2 g C60/C plasma jet output and technology is adaptable to ITER acceptable materials (BN and Be) for disruption mitigation. Work supported by US DOE DE-FG02-08ER85196 grant.

  15. MOLECULAR IMPRINTED POLYMERS—Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LIHaitao; XUMancai; 等


    Molecular imprinted polymers(MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules,These novel functional polymers have promised potential applications in racemic resolution,sensor,chromatography,adsorptive separation and other fields.This review exhibits the approach for preparing MIPs,the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs.The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  16. Modeling adsorption and reactions of organic molecules at metal surfaces. (United States)

    Liu, Wei; Tkatchenko, Alexandre; Scheffler, Matthias


    response effects enables reliable modeling of structure and stability for a broad class of organic molecules adsorbed on metal surfaces. This method was demonstrated to achieve quantitative accuracy for aromatic hydrocarbons (benzene, naphthalene, anthracene, and diindenoperylene), C60, and sulfur/oxygen-containing molecules (thiophene, NTCDA, and PTCDA) on close-packed and stepped metal surfaces, leading to an overall accuracy of 0.1 Å in adsorption heights and 0.1 eV in binding energies with respect to state-of-the-art experiments. An unexpected finding is that vdW interactions contribute more to the binding of strongly bound molecules on transition-metal surfaces than for molecules physisorbed on coinage metals. The accurate inclusion of vdW interactions also significantly improves tilting angles and adsorption heights for all the studied molecules, and can qualitatively change the potential-energy surface for adsorbed molecules with flexible functional groups. Activation barriers for molecular switches and reaction precursors are modified as well.

  17. Fullerene-C60 derivatives prevent UV-irradiation/ TiO2-induced cytotoxicity on keratinocytes and 3D-skin tissues through antioxidant actions. (United States)

    Kato, Shinya; Aoshima, Hisae; Saitoh, Yasukazu; Miwa, Nobuhiko


    Microcorpuscular titanium dioxide (TiO2), a useful sunscreen agent, photocatalyzes generation of reactive oxygen species (ROS). We assessed protective effects of fullerene-C60 derivatives or microcolloidal platinum (Pt) against ultraviolet ray (UV)-irradiation in the presence of TiO2 in vitro. UV-irradiation (8 J/cm2, mixed UVA and UVB) in the presence of 15 ppm TiO2 on HaCaT keratinocytes decreased cell viability as quantified by WST-1 assay, and increased both intracellular ROS and cell-membrane-lipid peroxidation, as quantified by nitroblue-tetrazolium (NBT) assay and diphenyl-1-pyrenylphosphine (DPPP) assay, respectively, whereas all of three phototoxicity-related symptoms were appreciably repressed almost to UV-unirradiational levels by pretreatment with polyvinylpyrrolidone-entrapped fullerene-C60 (C60/PVP) or fullerene-C60 dissolved in squalane (C60/Sqn) in a dose-dependent manner of C60, but scarcely by PVP alone or Sqn alone. In contrast, Pt repressed intracellular ROS generation, but did not prevent either peroxidation of cell-membrane-lipid or cell mortality. Then in the epidermis of 3-dimensional human skin tissue model, UV-irradiation in the presence of TiO2 extensively induced two symptoms such as ROS-generation around perinuclear regions and membrane-lipid peroxidation, both of which were repressed by C60/PVP or C60/Sqn, whereas Pt did not prevent membrane-lipid peroxidation adequately. Thus the advantageous application of the lipophilic antioxidant fullerene-C60 which effectively protects cell membrane against peroxidation. In conclusion, fullerene-C60 can be expected to serve as an antioxidant for scavenging of TiO2-photocatalyzed ROS in the skin surface, and therefore provide a functional improvement of TiO2-containing sunscreens.

  18. Synthesis of silica adsorbent and its selective separation for flavone

    Institute of Scientific and Technical Information of China (English)

    Yuqing ZHANG; Yahui ZHANG; Zhen QIN; Zhenrong MA


    One kind of built,in silica adsorbent, which has high adsorption selectivity to rutin, was synthesized using molecular imprinting technology by the following steps:synthesis of precursor from the reaction between water soluble rutin (as template molecule) and the functional monomer chloropropyltriethoxysilane, co,hydrolysis of the precursor and tetraethoxysilane (TEOS), sol,gel aging process, and removal of template molecules. The results of adsorption experiment show that this adsorbent has a high adsorption capacity for rutin, and good adsorptionselectivity towards rutin even under the interference of a flavone with a similar structure. TEM photos suggest that nanocaves corresponding to rutin were formed inside the adsorbent while FTIR spectra indicate that new bond was generated during the recognition process.

  19. Absolute Total Photoionization Cross Section of C60 in the Range of 25-120 eV: Revisited (United States)

    Kafle, Bhim P.; Katayanagi, Hideki; Prodhan, Md. Serajul I.; Yagi, Hajime; Huang, Chaoqun; Mitsuke, Koichiro


    The absolute total photoionization cross section σabs,I of gaseous C60 is measured in the photon energy hν range from 25 to 120 eV by photoionization mass spectrometry with synchrotron radiation. The absolute detection efficiencies of photoions in different charge states are evaluated. The present σabs,I curve is combined with the photoabsorption cross section curves of C60 at hν=3.5--26 eV in the literature, after appropriate alterations of the vapor pressure are taken into account. The oscillator strengths are computed from the composite curve to be 178.5 and 230.5 for the hν ranges from 3.5 to 40.8 eV and from 3.5 to 119 eV, respectively. These oscillator strengths agree well with those expected from the Thomas-Kuhn-Reiche sum rule and 60 times the photoabsorption cross section of a carbon atom. Moreover, the present σabs,I curve behaves similarly to the relative photoionization cross section curve reported by Reinköster et al.

  20. Fullerenol C60(OH)24 nanoparticles decrease relaxing effects of dimethyl sulfoxide on rat uterus spontaneous contraction (United States)

    Slavic, Marija; Djordjevic, Aleksandar; Radojicic, Ratko; Milovanovic, Slobodan; Orescanin-Dusic, Zorana; Rakocevic, Zlatko; Spasic, Mihajlo B.; Blagojevic, Dusko


    Dimethyl sulfoxide (DMSO) is a widely used solvent and cryoprotectant that can cause impaired blood flow, reduction in intracranial pressure, tissue edema, inflammatory reactions, inhibition of vascular smooth muscle cell migration and proliferation, processes which can lead to atherosclerosis of the coronary, peripheral and cerebral circulation. Although the adverse effects are rare when DMSO is administered in clinically established concentrations, there is no safe antagonist for an overdose. In this work, we treated isolated spontaneous and calcium-induced contractile active rat uteri (Wistar, virgo intacta), with DMSO and fullerenol C60(OH)24 nanoparticle (FNP) in DMSO. FNP is a water-soluble derivative of fullerene C60. Its size is a 1.1 nm in diameter and is a very promising candidate for a drug carrier in nanomedicine. FNP also displays free radical scavenging activity. DMSO decreased both spontaneous and calcium-induced contractions. In contrast, FNP only decreased spontaneous contraction. FNP decreased copper-zinc superoxide dismutase activity and prevented the DMSO-induced increase in glutathione reductase activity. Atomic force microscopy detected that FNP aggregated with calcium ions. Our results indicate that FNP has properties that make it a good candidate to be a modulator of DMSO activity which could minimize side effects of the latter.