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1.
Adam D. Darwish Ala'a K. Abdul-Sada Roger Taylor 《Fullerenes, Nanotubes and Carbon Nanostructures》2006,14(1):111-124
Pyrolytic trifluoromethylation of [76], [78], [84], and aza[60]fullerenes with silver trifluoroacetate at 300°C results in extensive polyaddition of up to 18, 18, 20 and 20 CF3 groups, respectively. In contrast to trifluoromethylation of [60]- and [70]fullerenes that give a full range of derivatives ranging upwards from Cn(CF3)2, [76]-, [78]-, and [84]-fullerenes only give Cn(CF3)6-18 derivatives, largely in the 10-12 CF3 range; reaction with [76]fullerene is accompanied by formation of C60(CF3)6 attributed to cage fragmentation. For aza[60]fullerene the hexa-addition level dominates, in contrast to its other reactions which give predominantly penta-addition products. All the compounds showed peaks at 1256±2 and 1180-1190 cm-1, due to the CF3 group, and peaks in this region are shown also by the soluble extract obtained on trifluoromethylation of nanotubes. As in trifluoromethylation of [60]- and [70]-fullerenes, the products obtained initially are involatile, attributed to formation os silver complexes; these are decomposed on subsequent solution in toluene. Mixed isomeric trifluoromethylated C60F8 derivatives viz. C60F7CF3, C60F6(FG3)2, C60F5(CF3)3 and C60F4(CF3)4, and C60F4CF3CF2CF3 (a C60F6 derivative) have been isolated from fluorination of [60]fullerene with MnF3/K2NilF6 at 510°C. 相似文献
2.
Yu. M. Shul'ga V. E. Muradyan V. M. Martynenko B. P. Tarasov N. V. Polyakova 《Fullerenes, Nanotubes and Carbon Nanostructures》2006,14(2):243-247
The mass-spectrometric investigation of the gases evolved from fluorinated multi-walled carbon nanotubes under heating was carried out. It was shown that in temperature interval from 20°C to 120°C the gases are composed predominantly of CO2, CO and H2O. Molecules of COF2 can be finding in gas phase of products of decomposition at 120-300°C. Molecules of CF4 and C2F6 realized from fluorinated nanotubes at 300-450°C. 相似文献
3.
Matthew D. Francis Olga V. Boltalina John F. Nixon Roger Taylor 《Fullerenes, Nanotubes and Carbon Nanostructures》2003,11(2):115-120
Evidence for the first η6 derivative of a fullerene, [MoC60F18(CO)3] has been obtained from reaction between [Mo(CH3CN)3(CO)3] and C60F18. 相似文献
4.
Dieter Heymann Sergei M. Bachilo Sem Aronson 《Fullerenes, Nanotubes and Carbon Nanostructures》2005,13(1):73-88
Ozonation of C60 in o-xylene produced three C60(O3)2 diozonides that were separated from one another and from two C60(O3)3 triozonides by High Performance Liquid Chromatography (HPLC). Upon thermolysis at 10, 15, and 16.6°C, each of the diozonides dissociated sequentially, first to a C60O(O3) oxyozonide, then to a C60O2 diepoxide. The three diepoxides were stable in solution for at least 3 weeks. The mean lifetimes of the three diozonides were 52 ± 5, 62 ± 6, and 17.3 ± 1.8 min, respectively (all at 15°C). The mean lifetimes of the three oxyozonides were 69.7 ± 0.7 and 58 ± 6 min at 16.6°C, respectively and about 240 min at 10°C. Photolysis of the diozonides yielded two dioxidoannulenes with UV-Vis adsorption maxima at 333 and 332 nm, and what appeared to be an epoxide-oxidoannulene with UV-Vis adsorption maximum at 327 nm. These annulenes were observed to form dimers. We have synthesized and characterized six C60O2 dioxides, at least three and possibly four of which were hitherto unknown. We report the discovery of oxyozonides that form during the dissociation of diozonides. 相似文献
5.
Adam D. Darwish Paul R. Birkett G. John Langley Harold W. Kroto Roger Taylor David R. M. Walton 《Fullerenes, Nanotubes and Carbon Nanostructures》1997,5(4):705-726
Heating a mixture of [60]fullerene, bromine, ferric chloride and benzene under reflux for 24 h products a range of phenylated [60]fullerene derivatives. The main product is C60Ph5H but other components identified by mass spectrometry (and in some cases separated by HPLC) are: C6oPhn(n = 4, 6, 8, 10, 12), C60PhnO2(n = 4, 6, 8, 10, 12), C60PhnOH (n = 7, 9, 11), C60PhnH2 (n = 4, 10), C60Ph4H4, C60Ph5H3, C60Phn02H (n = 5, 9), C60Ph4C6H4O2, C60Ph9OH3, and C60Ph11 O3H2. In the corresponding reaction with toluene, the crude reaction mixture contained C60(MeC6H4)4 as a main product; C60(ClC6H4)5H was obtained from the reaction with chlorobenzene. Formation of these derivatives is believed to involve radical bromination of the fullerene, followed by electrophilic substitution of the hatogenofullerene into the aromatic, accompanied in some case by hydrolysis, elimination and epoxide formation; oxidation may also introduce ketone/dioxetane functionality. The EI mass spectra of C60Ph4O2 and C60Ph8O2show degradation to C58Phn (n = 0-8), having structures believed to be related to the pseudofollerenes C68Phn (n = 0-8) reported recently. These results suggest that some derivatisations of fullerenes confer stability, due to the relief of strain. 相似文献
6.
Larisa S. Karpushenkava Gennady J. Kabo Vladimir V. Diky 《Fullerenes, Nanotubes and Carbon Nanostructures》2007,15(4):227-247
Thermodynamic properties of fullerene hydride C60H36 in the ideal-gas and crystal states were studied by theoretical methods. Molecular structures and vibration frequencies were calculated for 9 isomers of C60H36 by the density functional theory (DFT) by use of a combination of the B3LYP functional with 6-31G* basis sets. Ideal-gas thermodynamic properties were calculated based on those parameters. Enthalpies of formation of C60H36 isomers in the ideal-gas state were derived from homodesmic reactions involving adamantane, cyclohexane, and C60 fullerene. Using the standard methods of statistical mechanics, heat capacity and derived thermodynamic properties of crystalline C60H36 were calculated at 340-1000 K that extended the range of experimental measurements. With a crystal-gas heat capacity difference, the experimental value of sublimation enthalpy was extrapolated to room temperature as ΔsubHmo (298.15 K)=(193±10) kJ · mol-1. Combining this value with the known experimental enthalpy of formation in the crystalline state, the ideal-gas enthalpy of formation of C60H36 at the synthesized sample isomer composition was obtained: Δf Hmo (298.15 K)=(1206±28) kJ · mol-1. Equilibrium constants and compositions were calculated for the reactions of hydrogenation of C60 fullerene in different states. It was shown that C60 can act as a hydrogen accumulator. 相似文献
7.
H. Takahashi E. Matsubara M. Shiro S. Matsubara N. Sato A. Muramatsu K. Tohji 《Fullerenes, Nanotubes and Carbon Nanostructures》2002,10(3):217-226
A new method to synthesize fullerene and sulfur compounds has been developed. Using this method, C60S16 and C70S16 compounds were grown from dilute fullerene and sulfur toluene solution. Their atomic structures were analyzed by x-ray diffraction with the single crystal. The C60S16 crystal is C-centered monoclinic structure of a=2.0874 nm, b=2.1139 nm, c=1.05690 nm and β=111.93°, and the C70S16 has a primitive monoclinic, P21/c, with lattice parameters of a=1.5271 nm, b=1.49971 nm, c=2.18024 nm and β=109.791°. In this compound, the structure of fullerenes is maintained and sulfur atoms form S8 rings placed around the fullerenes. 相似文献
8.
D. A. Bradley D. R. Dance S. H. Evans C. H. Jones 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1989,280(2-3):380-383
A variant of the multisection filter and annular target geometry, with a designed angular acceptance of ±0.5°, has been utilised in measuring accurate. O(5%), absolute total differential scattering cross sections of 60 keV photons for H2O, methyl methacrylate (C5H8O2)n and nylon-6 (C12H22O3N2)n in the angular scattering range of 2°–10°. The effects of molecular correlations manifest, to varying degree, in strong forward peaking of the scattered photon distribution. Comparison is made with available experiment and theory. 相似文献
9.
Yury I. Lyakhovetsky Elena A. Shilova Boris L. Tumanskii Alexander V. Usatov Era A. Avetisyan Sergei R. Sterlin Alexandra P. Pleshkova Yuri N. Novikov Yuri S. Nekrasov Roger Taylor 《Fullerenes, Nanotubes and Carbon Nanostructures》1999,7(2):263-287
Both [60]- and [70]fullerene react with either the Scherer radical (perfluorodiisopropylethylmethyl, C9F19), a mixture of branched perfluorononenes (C9F18, the product of hexafluoropropene trimerization), or β-fluorosulphatotetrafluoroethyldiheptafluoroisopropylmethyl radical (C9F18OSO2F) in the ionization chamber of a mass spectrometer to give the positive parent ions of trifluoromethylation products, the reaction being accompanied by hydrogen addition. The reaction occurs at least partly on the walls of the ionization chamber, by a radical mechanism employing CF3 radicals formed from the radical reactants both thermally and under electron impact; only the latter route occurs with the perfluorononenes. 相似文献
10.
Sergei I. Troyanov Olga V. Boltalina Igor V. Kouvytchko Pavel A. Troshin Erhard Kemnitz Peter B. Hitchcock Roger Taylor 《Fullerenes, Nanotubes and Carbon Nanostructures》2002,10(3):243-259
The solubility of C60F18 in aromatic hydrocarbons, benzene, toluene, and xylenes (0.48-1.23 mg/mL), and decomposition enthalpies for the 1 : 1 and 1 : 2 complexes (31-70 kJ/mole) have been determined. The C60F18 molecule has near perfect C3v symmetry, and the x-ray single-crystal structures of the C60F18 L complexes (L=hexamethylbenzene, o-, m-, p-xylene, and bromobenzene) are compared in terms of 12 types of C-C and four types of C-F bonds. Analysis of the packing modes in the crystals shows an influence of the size and polarity of the aromatic hydrocarbon molecule. 相似文献
11.
Franco Cataldo 《Fullerenes, Nanotubes and Carbon Nanostructures》2003,11(4):295-316
Hydrogenated C60 fullerene, C60H36 was prepared in different solvents using Zn/HCl as reducing agents. The structure of C60H36 was confirmed both by electronic and FT-IR spectroscopy and the purity of the reaction product was checked by HPLC analysis. It has been confirmed that C60H36 is not stable in air, especially in presence of light which enhances the oxidation. The oxidation of C60H36 was studied by FT-IR spectroscopy and by differential scanning calorimetry (DSC) in air; the formation of hydroxyl groups on the fullerene cage and ketonic groups (involving cage breakdown) have been detected. Furthermore, the action of O3 on C60H36 was investigated and it has been found that O3 exerts practically the same effect of air but causing an enhanced cage breakdown. The thermal stability of C60H36 was checked by a thermogravimetric analysis (TGA) coupled with a differential thermal analysis (DTA) under N2 flow. The vaporization of C60H36 occurs at very high temperature: the DTA trace has shown an endothermic peak at 540°C (at a heating rate of 20°C/min). C60H36 shows an electronic absorption spectrum with a maximum at about 217 nm and it is able to match both in position and in half width the peak at 217.5 nm observed in the spectrum of the interstellar extinction of light which was attributed to hydrogenated, radiation processed and thermally annealed carbon dust. Similarly, the absorption spectrum of C60H36 is able to match several infrared emission bands (called UIBs) detected from certain astrophysical objects like the protoplanetary nebulae (PPNe). It is proposed that hydrogenated fullerenes can be used as model compounds in the laboratory simulation studies of interstellar carbon dust. 相似文献
12.
Joan M. Street Thomas Drewello Yury Vasil'ev Olga V. Boltalina Roger Taylor 《Fullerenes, Nanotubes and Carbon Nanostructures》2004,12(4):753-764
From the product of fluorination of [60]fullerene with K2PtF6 at 470 °C, we have isolated a small quantity (ca. 0.5 mg) of C60F16O, an oxahomofluorofullerene (ether) of exceptionally long HPLC retention time (50% greater than any other known fluorofullerene). The 19F NMR spectrum consists of 16 main lines and 8 minor ones, due to C60F16O (a single isomer of C1 symmetry) and C60F16, respectively. The presence of the latter (absent on initial isolation) indicates this ether to be relatively unstable, confirmed by the failure to obtain an EI mass spectrum. The empirical formula was therefore determined by MALDI-TOF mass spectrometry in the negative-ion mode, the laser fluence being carefully adjusted at the threshold of ion formation, whence the only observable signal corresponded to the molecular ion of C60F16O. At slightly higher laser fluence, the base peak of C60F16O·- is accompanied by C60F16·- and C60F15O·-. Two closely similar structures (of similar calculated stabilities) are fully consistent with the NMR data. Calculated dipole moments and the exceptionally long retention HPLC retention times suggest that both C60F16 and C60F16O may be dimers. 相似文献
13.
Nai-Xing Wang 《Fullerenes, Nanotubes and Carbon Nanostructures》2003,11(3):227-235
Thermal decomposition of C60H2 in C6D4Cl2 solution at 236°C for 2 hours was shown to produce hydrogen as a product, the hydrogen production was successfully followed by NMR. In order to further explore the rule of thermal decomposition of C60H2, the dynamics of decomposition reaction was studied and the results showed this decomposition reaction accorded with first order reaction dynamical equation. The experiment temperature was ranged separately in 459K, 455K, 451K, and 446K. 相似文献
14.
H. Nakayama K. Takatsuji K. Murakami Y. Miura N. Shimoyama H. Machida 《Thin solid films》2003,430(1-2):87-90
Cat-CVD method has been applied to the growth of Si–C and Si–C–O alloy thin films. Growth mechanism has been studied with emphasis on the effects of filament materials. Growth rates and alloy compositions were measured for W, Ta, Mo and Pt filaments at the filament temperatures ranging from 1300 to 2000 °C. Si1−xCx films with x ranging from 0.38 to 0.7 could be grown by using single molecule source Si(CH3)2H2 (dimethylsilane). Si–C–O ternary alloy films was successfully prepared by using Si(OC2H5)4 (tetraethoxysilane) and Si(CH3)2(OCH3)2 (dimethyldimethoxysilane) molecules. 相似文献
15.
Menghai Lin Ying-Nan Chiu Shan-Tao Lai Jimei Xiao Man-Zheng Fu 《Fullerenes, Nanotubes and Carbon Nanostructures》1997,5(1):111-126
In this paper, we studied the equilibrium geometries, the electronic structures and the binding energies of fullerene C32 as well as its hydrogenates and fluorides interactions by the SCF Hartree-Fock calculations using the latest version of GAMESS of ab initio programs. The fullerene C32 is found to have a 1A2' closed-shell ground state in D3d symmetry or a 1EU singlet state in D3h symmetry. It is predicted to be easy to add some hydrogen or fluorine atoms to the C32 cage and to produce a series of derivatives C32H2n,C32F2n (n=l, 3, 6), in which C32H2,C32F2 (D3d), C32H6a,C32F6c(D3h) are more stable. We suggest that this implies that the vertex of triplet pentagons of the C32 cage is an activation site for addition. 相似文献
16.
Nobuaki Kitazawa Toru Ito Daisuke Sakasegawa Yoshihisa Watanabe 《Thin solid films》2006,500(1-2):133-137
Thin films of microcrystalline (C8H17NH3)2PbBr4 were prepared by a two-step growth process as follows: (1) deposition of PbBr2 films on substrates and (2) self-organized growth of layered perovskite compounds by exposing the PbBr2 film to C8H17NH3Br vapor in a vacuum chamber. As-synthesized (C8H17NH3)2PbBr4 films were characterized by using X-ray diffraction, temperature dependence in optical absorption and photoluminescence spectra. (C8H17NH3)2PbBr4 films created by this synthesis approach were found to microcrystalline form, single phase and highly oriented with a c-axis perpendicular to the substrate surface. (C8H17NH3)2PbBr4 films showed clear exciton absorption and photoluminescence even at room temperature in the near-ultraviolet region. Exciton binding energy of (C8H17NH3)2PbBr4 was estimated about 200 meV. 相似文献
17.
V.H. Gillette N.E. Patio J.R. Granada R.E. Mayer 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1989,280(2-3):273-284
Using a synthetic incoherent scattering function which describes the interaction of neutrons with molecular gases we provide analytical expressions for zero- and first-order scattering kernels, σ0(E0 → E), σ1(E0 → E), and total cross section σ0(E0). Based on these quantities, we have performed calculations of thermalization parameters and transport coefficients for H2O, D2O, C6H6 and (CH2)n at room temperature. Comparison of such values with available experimental data and other calculations is satisfactory. We also generated nuclear data libraries for H2O with 47 thermal groups at 300 K and performed some benchmark calculations (235U, 239Pu, PWR cell and typical APWR cell); the resulting reactivities are compared with experimental data and ENDF/B-IV calculations. 相似文献
18.
Jih Ru Hwu Kok-Thiam Yong Sheng Fa Yu Chung-Sun Chung 《Fullerenes, Nanotubes and Carbon Nanostructures》1997,5(5):1009-1020
“Saturnized fullerene C60 molecules” were designed as the cardinal points for cross-linked polymers. Results from the graphic molecular modeling, including the CVFF calculations, indicate that the 1, 2-adduct [-N(CH2)6-]6·C6oH6with S6 symmetry is the best target molecule. 相似文献
19.
Q. Gou 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2006,560(2):617-620
The measurement of YBJ-ARGO Resistive Plate Chamber (RPC), working in avalanche mode was performed. With different component of i-C4H10 in C2H2F4-based gas mixtures C2H2F4/i-C4H10/SF6, the behavior of the detector with respect to the high voltage was studied. The experiment confirms that it is possible to operate YBJ-ARGO RPC in avalanche mode. The results show that with the gas mixtures containing 10% of i-C4H10 the detector achieves its optimum performance. 相似文献
20.
David M. Thompson John H. Brownie Michael C. Baird 《Fullerenes, Nanotubes and Carbon Nanostructures》2004,12(3):697-713
The carbonylate anions [M(CO)5]- (M = Mn, Re), [Co(CO)4]-, [CpFe(CO)2]-, and [CpM(CO)3]- (M = Mo, W) react with C70 via single electron transfer processes to give, respectively, the corresponding 17-electron, metal-centered radicals Co(CO)4, M(CO)5 (M = Mn, Re), CpFe(CO)2, and CpM(CO)3 (M = Mo, W) in addition to the radical anion C70-. In secondary thermal or photochemical processes, the metal-centered radicals Co(CO)4 and M(CO)5 (M = Mn, Re) combine with the C70- to form the new η2-C70 complexes [Co(CO)3(η2-C70)]- and [M(CO)4(η2-C70)]-. However, the metal-centered radicals CpM(CO)3 (M = Mo, W) require photolysis to react with C70- to form [CpM(CO)2(η2-C70)]-, whereas neither thermolysis nor photolysis induces reaction between CpFe(CO)2 and C70-. The photochemical reaction of [Mn(CO)5]- with a mixture of higher fullerenes known to contain at least C76, C78, C84, C86, and C90 resulted similarly in the formation of the higher fullerene complexes [Mn(CO)4(η2-Cn)]- (n = 76, 78, 80, 82, 84, 86, 88, 90, 92, 96, and 98), all identified using electrospray mass spectrometry. 相似文献