C120On from C60Br24
Abstract: Microcrystalline mixture of fullerene dimer oxides (C120On; na 1; 2; 3; .. .) was extracted from decomposed C60Br24. Low-temperature FTIR studies of the product showed the absence of orientational ordering transitions indicating freezing of C60 rotations due to inter-cage bonding and epoxidation. Characteristic features due to inter-cage vibrations are seen in the far IR spectrum. Bond cleavages in MS/MS leave all the oxygen atoms of the dimer oxide with one fullerene molecule. We propose that dimers are formed byâ3a 2a cycloaddition of C60 with its oxides, C60On rather than cycloaddition of the monomeric oxides. Results are discussed based on the possible reaction sequences. ” 2001 Elsevier Science B.V. All rights reserved.
Topics: Dimer (53%), Cycloaddition (52%), Fullerene (50%)
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TL;DR: The FTIR vibrational spectroscopy is presented, without claiming to cover entire field, for the characterization of diamond, amorphous carbon, graphite, graphene, carbon nanotubes, fullerene and carbon quantum dots.
Abstract: Fourier transform Infrared (FTIR) spectroscopy is a versatile technique for the characterization of materials belonging to the carbon family. Based on the interaction of the IR radiation with matter this technique may be used for the identification and characterization of chemical structures. Most important features of this method are: non-destructive, real-time measurement and relatively easy to use. Carbon basis for all living systems has found numerous industrial applications from carbon coatings (i.e. amorphous and nanocrystalline carbon films: diamond-like carbon (DLC) films) to nanostructured materials (fullerenes, nanotubes, graphene) and carbon materials at nanoscale or carbon dots (CDots). In this paper, we present the FTIR vibrational spectroscopy for the characterization of diamond, amorphous carbon, graphite, graphene, carbon nanotubes (CNTs), fullerene and carbon quantum dots (CQDs), without claiming to cover entire field.
363 citations
Cites background from "C120On from C60Br24"
...…674 – C60 and C70 coexist, C70 Alves et al., 2006; Bethune et al., 1991 669 Hg(3) and Hg(4) C120On dimer oxide, Hg(3) and Hg(4) vibrational modes of C60 Resmi et al., 2001 667 b2u C20 (D2h) Zhang et al., 2007 651 au C20 (D2h) Zhang et al., 2007 650 b2u C20 (D2h) Zhang et al., 2007 645–630 e1 ’…...
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...…b2g C20 (D2h) Zhang et al., 2007 733 b1u C20 (D2h) Zhang et al., 2007 727 Hg(3) and Hg(4) C120On dimer oxide, Hg(3) and Hg(4) vibrational modes of C60 Resmi et al., 2001 725–720 a2 ’ C70 Iglesias-Groth et al., 2011; Meilunas et al., 1991; Menon et al., 1996 723 b3g C20 (D2h) Zhang et al., 2007 721…...
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...H) C60 modified in plasma, confirm an aromatic structure Vijayalakshmi1 et al., 2014 847 Hg(3) and Hg(4 C120On dimer oxide, Hg(3) and Hg(4) vibrational modes of C60 Resmi et al., 2001 823 d (=C–...
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...C20, finger print for bow-ti isomer Zamani et al., 2014 805 Hg(3) and Hg(4) C120On dimer oxide, Hg(3) and Hg(4) vibrational modes of C60 Resmi et al., 2001 805 ds (N–...
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...…1996 644 Hg(3) and Hg(4) C120On dimer oxide, Hg(3) and Hg(4) vibrational modes of C60 Resmi et al., 2001 642 – C60 and C70 coexist, C70 Alves et al., 2006; Bethune et al., 1991 625 au C20 (D2h) Zhang et al., 2007 604 F1u(2) C120On dimer oxide, F1u(2) vibrational modes Resmi et al., 2001 603 (C–...
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Abstract: Oxygen adducts were among the first reported fullerene derivatives, and they have continued to be the subject of many subsequent investigations by experimental and theoretical researchers. A literature survey is presented summarizing the preparation, purification, characterization, and stabilities of fullerene oxides and ozonides. Published data on the 13C NMR spectra, thermal dissociation reaction products and kinetics, and photolysis products of these compounds are compiled and presented in tabular form. To cite this article: D. Heymann and R.B. Weisman, C. R. Chimie 9 (2006).
37 citations
Abstract: Oxygenated fullerenes anions were produced by a vaporization source equipped with a corona discharge ionizer in the presence of a trace amount of oxygen. In situ mass analysis revealed that the species formulated as C60On− (n⩽30) were formed in the source and that the degree of oxygenation could be altered by the discharge current. Formation of the epoxide structure in the C60On− was suggested by XPS measurements for thin films prepared by deposition of the C60On− beam. The structures and formation processes of higher analogues (C60)mOn− (m=2,3) are briefly discussed.
11 citations
TL;DR: It was found that the clusters are reinforced; that is, they are not broken by electron beams any more, and the actual mechanism of the reinforcement of the clusters has not yet been clearly understood and therefore is an open question.
Abstract: We carry out two experiments: (1) the formation of clusters composed of C60 molecules via self-assembly and (2) the reinforcement of the clusters. Firstly, clusters such as fibres and helices composed of C60 molecules are produced via self-assembly in supercritical carbon dioxide. However, C60 molecules are so weakly bonded to each other in the clusters that the clusters are broken by the irradiation of electron beams during scanning electron microscope observation. Secondly, UV photons are irradiated inside a chamber in which air is filled at 1 atm and the above clusters are placed, and it was found that the clusters are reinforced; that is, they are not broken by electron beams any more. C60 molecules located at the surface of the clusters are oxidised, i.e. C60On molecules, where n = 1, 2, 3 and 4, are produced according to time-of-flight mass spectroscopy. It is supposed that oxidised C60 molecules at the surface of the clusters may have an important role for the reinforcement, but the actual mechanism of the reinforcement of the clusters has not yet been clearly understood and therefore is an open question.
5 citations
Abstract: The optical properties of layers of C60 fullerene on a silicon substrate are studied before and after a reducing annealing at 900–1050°;C in a hydrogen atmosphere in order to detect the formation of silicon-carbide clusters. It is shown, on the basis of Raman scattering, infrared absorption, time-resolved photoluminescence spectra, and ellipsometric measurements, that the SiC clusters are not detected at the accuracy of the methods used. After annealing, the layer is in the form of a porous hydrogen-rich film of disordered graphite, possibly with a small amount of fullerene molecules.
1 citations
References
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NEC1
Abstract: CAPPED hollow carbon nanotubes1,2 can be modified into nanocomposite fibres by simultaneous opening of the caps (by heating in the presence of air and lead metal) and filling of the interior with an inorganic phase3. To generalize this approach, greater understanding is needed of the reaction mechanism between the tube caps and oxygen. Here we report that the oxidation of carbon nanotubes in air for short durations above about 700 °C results in the etching away of the tube caps and the thinning of tubes through layer-by-layer peeling of the outer layers, starting from the cap region. The oxidation reaction follows an Arrhenius-type relation with an activation energy barrier of about 225 kJ mol−1 in air. Heating of closed nanotubes with an oxide (Pb3O4) in an inert atmosphere lowers the activation barrier for the reaction and opening of the tubes occurs at lower temperatures. Contrary to intuition, however, open tubes are much more difficult to fill with inorganic materials than in the one-step filling of tubes reported previously3. But various other experiments might be possible in the inner nano-cavities of the open tubes such as studies of catalysis and of low-dimensional chemistry and physics.
993 citations
01 Jan 1976-
Abstract: Spin coating is demonstrated to be a promising technique for depositing magnetic transition metal complexes. The thin films show nano-crystalline formations with random orientations. The optical properties determined using spectroscopic ellipsometry compare well to those of single molecules in solution indicating the preservation of the molecular structure upon the deposition process. © 2006 Elsevier B.V. All rights reserved.
864 citations
Book•
01 Aug 1995-
Abstract: Initially envisaged as rather unreactive, aromatic-like molecules, the fullerenes instead undergo a wide variety of reactions characteristic of alkenes. The many derivatives of C60, and the few of C70, that have now been reported offer new directions for organic chemistry.
594 citations
"C120On from C60Br24" refers background in this paper
...From the low-temperature FTIR study, it is evident that the C60 balls in these dimers are not free to rotate unlike the case of pristine C60 and C60 derivatives such as C60O [28] and C60Br24 [29] which also show the orientational ordering transition....
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...The low-temperature FTIR study of the fullerene dimer oxides (Fig....
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...FTIR studies were performed with a Perkin Elmer Spectrum RXI FTIR spectrometer....
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...Purity of the product was checked with the FTIR spectroscopy....
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...A Leybold commercial cryostat was used for low-temperature FTIR measurements....
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TL;DR: The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C60 and C70 in a total amount of 3 to 4% by weight that are identified as higher fullerenes.
Abstract: The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C(60) and C(70) in a total amount of 3 to 4% by weight. Repeated chromatography of this material on neutral alumina has led to the isolation of stable solid samples of C(76), C(84), C(90), and C(94). The characterization, which includes mass spectrometry, (13)C nuclear magnetic resonance, electronic absorption (ultraviolet/visible) and vibrational (infrared) spectroscopy identifies these all-carbon molecules as higher fullerenes. In addition, C(70)O, a stable oxide, has been isolated that is structurally and electronically closely related to D5h-C(70). This compound forms during the resistive heating process and probably has an oxygen atom inserted between two carbon atoms on the convex external surface of the C(70) skeleton.
586 citations
Abstract: The isolation of C{sub 60} in preparatively useful quantities has stimulated intensive efforts to generate and characterize functional derivatives. Many reactions of C{sub 60} furnish complex, inseparable mixtures of products, and only a few discrete, monofunctional congeners have been described to date. We now report that photooxidation of C{sub 60} in benzene furnishes a single monooxide, C{sub 60}O, as the sole isolable product. Moreover, we have obtained the same species as a byproduct of the synthesis of C{sub 60}. Spectroscopic analysis strongly supports the epoxide structure. It is demonstrated that C{sub 60}O is efficiently converted to C{sub 60} in a 91% yield during chromatography of neutral alumina. The widespread use of alumina for purification of the fullerenes may explain why the fullerene oxide was not isolated before.
444 citations