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1.
For the first time the total and relative contents of the stable ozonolysis products of fullerene C70 solutions were identified by IR spectroscopy and elemental and chemical analyses. At the 100% conversion of C70 a mixture of products corresponding to the empirical formula C70O14.3H0.21 (epoxides: polyketones: polyesters: secondary fullerene ozonides (SFOZ): acids = 1.07: 6: 6: 0.21: 1.02) is formed. The content of polyketones, polyesters, acids, and SFOZ increases during the whole ozonolysis time (1 h). The number of oxygen atoms in epoxides C70O n (n = 1–4) is lower than that in epoxides C60O n (n = 1–6) formed by the ozonolysis of fullerene C60. The kinetic curve of accumulation of epoxides C70O n (n = 1–4) passes through a maximum, which is observed 0.5 min after the beginning of ozonolysis. No epoxides were identified among the products 3.5 min after the ozonolysis. The photoluminescence (PL) (λmax = 645 and 685 nm) of fullerene polyketones in glassy EtO2/EtOH solutions frozen at 77 K was observed. This PL is much brighter, than that of polyketones formed upon the ozonolysis of fullerenes C60. For the first time the chemiluminescence (CL) was detected and studied upon the ozonolysis of C70 solutions at 300 K. The CL emitters are excited states of fullerene polyketones. The CL spectrum is partially overlapped with the known CL spectrum appeared upon the ozonolysis of C60max = 685 nm) but contains the greater number of maxima (λmax = 645 and 685 nm), which is related to a lower symmetry of the C70 oxidation products.  相似文献   

2.
The structural and phase state of the C60-C70 system at various C60/C70 ratios in mixtures obtained by the vaporization of solutions in toluene at ∼98°C was studied by X-ray structure analysis, differential scanning calorimetry, and infrared spectroscopy. Solid solutions based on the face-centered cubic packing of C60 are not formed in the C60-C70 system at C70 contents from 0.5 to 50 wt %. The hexagonal close packing of a solid solution of C60 in C70 can be formed as a result of the thermally activated decomposition of the ternary crystal solvate in the C60-C70-C6H5CH3 system. The structural state of multiphase mixtures formed under conditions far from equilibrium is characterized by a high degree of structure imperfection and greater ability to undergo oxidation compared with C60 and C70.  相似文献   

3.
Knudsen cell mass spectrometry was used to study ion-molecular electron exchange reactions between some trifluoromethyl derivatives of C60 fullerene. Electron affinity values were experimentally determined for C60(CF3)10 and the S 6 isomer of C60(CF3)12 and compared with the results of calculations and the data in the literature.  相似文献   

4.
Features of the oxidation of C60 and C70 fullerites were studied by infrared spectroscopy. It was shown that for C60 fullerite, the presence of toluene residue reduces the temperature at which oxidation starts. The form of the toluene (solvate or nonsolvate) is not important. A low-frequency shift in the valence C-O-C vibrations of C70 fullerene due to local steric strains was discovered.  相似文献   

5.
Palladium and platinum complexes of fulleienes C60 and C70 containing the axially chiral ligand (—)-BITIANP (BITIANP is 2,2’-bis(diphenylphosphino)-3,3’-bi(benzo[b]thiophene)) and pynolidino[60]fullerene bearing a planar chiral organometallic π-complex substituent in the heteiocyclic ring were studied by circular dichroism (CD) spectroscopy.  相似文献   

6.
t-The electrochemical properties of exohedral complexes of transition metals with metallofragments coordinated to C60 and C70 fullerene ligands in different coordination modes are surveyed. The effect of the nature, composition, and structure of metal-containing fragments on the electrochemical properties of these complexes and stability of products formed in the oxidation and reduction of complexes is discussed.  相似文献   

7.
3′H-Cyclopropa[1,9](C60-Ih)[5,6]fullerene-3′-carboxylic acid can be synthesized in a good yield by cyclopropanation of fullerene C60 with 2-(dimethyl-λ4-sulfanylidene)acetates provided that the ester residue is readily hydrolyzable in acid medium.  相似文献   

8.
Systematic study of chlorination of fullerene C60 with inorganic chlorides SbCl5, VCl4, MoCl5, and KICl4 was carried out. Higher chlorofullerenes, viz., T h -C60Cl24, C60Cl28, C 2-C60Cl30, and D 3d -C60Cl30, can be prepared depending on the temperature and time of chlorination. The molecular and crystal structures of C60Cl24⋅VOCl3, C60Cl30⋅2CS2, and C60Cl30O1.22 were determined by single-crystal X-ray diffraction. Fullerenes C60Cl28 and C 2-C60Cl30 were shown to be only kinetically stable, whereas D 3d -C60Cl30 is a thermodynamically stable product. Transformations of less chlorinated fullerenes into more chlorinated products are accompanied by substantial changes in the addition patterns. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1608–1618, July, 2005.  相似文献   

9.
B3LYP/6-31G(d) hybrid HF/DFT and BLYP/6-31G(d, p) DFT calculations were carried out to determine the structural and electronic properties of the endohedral complex of C60 with Tetrahedral N4 (Td N4), N4@C60. It was demonstrated that N4 was seated in the center of the fullerene cage and the tetrahedral structure of N4 is remained in the cage. The formation of this complex is endothermic with inclusion energy of 37.92 kcal/mol. N4 endohedral doping perturbs the molecular orbitals of C60 not so much, the calculated HOMO–LUMO gaps, the electron affinity (EA) and the ionizational potential (IP) of N4@C60 are similar to that of C60.  相似文献   

10.
New chromatographically pure monoand hexamethanofullerenes C60 and C70 containing active allylic groups were synthesized by Bingel—Hirsch reaction. These compounds are promising for the studies of biological activity, as well as for obtaining on their basis new fullerenecontaining materials. The purity and composition of the synthesized compounds were confirmed by MALDI-TOF mass spectrometry and HPLC, their structure was established by 1H and 13C NMR spectroscopy and X-ray diffraction.  相似文献   

11.
Ground state non-covalent interactions between a macrocyclic receptor, C-methylcalix[4]resorcinarene (1) and fullerenes (C60 and C70) have been studied in benzonitrile by an absorption spectrophotometric method. Absorption bands are located in the visible region due to the charge transfer (CT) transition between 1 and various electron acceptors (including fullerenes), namely, 2,3-dichloro-5,6-dicyano-p-benzoquinone, tetracyanoquinodimethane and p-chloranil. Utilizing the CT absorption bands, various important physicochemical parameters, including oscillator strength, resonance energy, transition dipole strength of all the acceptor-1 complexes and vertical ionization potential of 1 are determined. Job’s method of continuous variation reveals 1:1 stoichiometry between fullerenes and 1. The most fascinating feature of the present study is that 1 binds selectively to C70 compared to C60 as obtained from binding constant (K) data of C60-1 (KC60-1K_{\mathrm{C}60\mbox{-}\mathbf{1}}) and C70-1 (KC70-1K_{\mathrm{C}70\mbox{-}\mathbf{1}}) complexes, i.e., KC60-1=190K_{\mathrm{C}60\mbox{-}\mathbf{1}}=190 dm3⋅mol−1 and KC70-1=5,800K_{\mathrm{C}70\mbox{-}\mathbf{1}}=5{,}800 dm3⋅mol−1 and selectivity (KC70-1 /KC60-1 ) ∼30. Quantum chemical calculations based on hybrid density functional theory estimate the enthalpies of formation of the fullerene-1 complexes in vacuo and provide very good support for selectivity in the K values of the C70 and C60 complexes of 1. The exchange and correlation energies have been calculated using a hybrid DFT functional method. We have opted to use the hybrid DFT functional over the Hartree-Fock method, as it can account for correlation effects also. Molecular electrostatic potential map calculations give a clear picture on the electronic structures of the fullerene-1 complexes.  相似文献   

12.
Sorption of fullerenes C60 and C70 from o-xylene, toluene, and dichlorobenzene solutions on NORIT-AZO carbons was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1638–1642.Original Russian Text Copyright © 2004 by Semenov, Seregin, Arapov, Charykov.  相似文献   

13.
Wariation of the concentration of fullerenes C60 and C70 in poly(methyl methacrylate) films under UV exposure in atmospheric oxygen was studied. The mechanism of the influence exerted by addition of some photostabilizing polymers and xanthene dyes on the photooxidative degradation of fullerene in the polymer matrix was analyzed.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 1038–1042.Original Russian Text Copyright © 2005 by Troitskii, Khokhlova, Konev, Denisova, Novikova, Lopatin.  相似文献   

14.
Fullerenyl radicals (FR) RC60 · and chemiluminescence (CL) are generated in the presence of O2 in C60—R3Al (R = Et, Bui) solutions in toluene (T = 298 K). The FR are formed due to the addition of the R· radical, which is an intermediate of R3Al autooxidation, to C60. Mass spectroscopy and HPLC were used to identify EtnC60Hm (n, m = 1–6), EtpC60 (p = 2–6), and dimer EtC60C60Et as stable products of FR transformations. As found by ESR, the EtC60 · radical (g = 2.0037) is also generated by photolysis of solutions obtained after interaction in the (C60— R3Al)—O2 system. In the presence of dioxygen, the FR is not oxidized but yields complexes with O2, which appear as broadening of the ESR signals. Chemiluminescence arising in the (C60—R3Al)—O2 system is much brighter (I max = 1.86·108 photon s−1 mL−1) than the known background CL (I max = 6.0·106 photon s−1 mL−1) for the autooxidation of R3Al and is localized in a longer-wavelength spectral region (λmax = 617 and 664 nm). This CL is generated as a result of energy transfer from the primary emitter 3CH3CHO* to the products of FR transformation: RnC60Hm, RpC60, and EtC60C60Et. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 205–213, February, 2007.  相似文献   

15.
Fluorocyclohexa adducts C60(C4F8) n were synthesized by high-temperature reaction of fullerene C60 with 1,2-C2F4I2 or 1,4-C4F8I2 in sealed tubes. Their separation by HPLC allowed us to determine molecular structure (X-ray diffraction) of four new compounds C6(C4F8) n (n = 2, 3, 4, and 6). Structures of isomers C60(C4F8) n were discussed in terms of a concept of consecutive addition of C4F8 groups to the fullerene cage.  相似文献   

16.
(U)PBE0/cc-pVDZ method is used to study the structure of C60Cl30, C60(OH)30 molecules and Fe@C60(OH)30 endocomplex. The triplet state of the endocomplex is shown to be the lowest in energy among its four states corresponding to different spin multiplicities and positions of Fe nucleus within the fullerene cavity. This state is characterized by bonding between the iron atom and one of two benzenoid cycles of the carbon cage, six internuclear Fe–C distances (208 pm), and 1s22s22p63s23p63d7.24s0.14p0.3 electron configuration of iron with spin population of 2.36.  相似文献   

17.
Methanofullerenes were directly synthesized under mild conditions by cycloaddition to fullerene C60 of diazoalkanes generated in situ by oxidation of ketone hydrazones containing a heterocyclic fragment with manganese(IV) oxide in the presence of the catalytic system Pd(acac)2-2 PPh3-4 Et3Al.  相似文献   

18.
The carbon cages composed of pentagons and heptagons (F5F7 isomers) are the analogs of fullerenes composed of pentagons and hexagons (F5F6 isomers). To provide insight into the structures and stability of the hydrides of F5F6 and F5F7 isomers, systematical density functional theory calculations are performed on all the 1,812 F5F6–C60H60 and 56 F5F7–C60H60. The calculated results demonstrate that the isomer with lowest/highest energy has most/fewest fused pentagons for both F5F6 and F5F7 hydrides and the stability of these hydrides increase with the number of fused pentagons roughly. The lowest energy F5F6–C60H60 and F5F7–C60H60 are 237.1 and 152.5 kcal/mol lower in energy than the isolated pentagon rule (IPR) C60H60, respectively; however, these two parent cages are 529.6 and 660.0 kcal/mol higher in energy than the IPR C60. The calculations suggest that heptagon-containing cages, not only those violating the IPR can be the candidate cages for fullerene derivatives and the possible repulsion between the added atoms may play an important role in determining the structures and stability of the hydrides of carbon cages.  相似文献   

19.
A rotating-bomb calorimeter was used to measure the energy of combustion of crystalline fullerene chloride C60Cl30 · 0.09Cl2, Δc U° = (?24474 ± 135 kJ/mol). The result was used to calculate the standard enthalpy of formation, Δf H° (C60Cl30, cr) = 135 ± 135 kJ/mol, and the C-Cl bond energy, 195 ± 5 kJ/mol. The C-X (X = F, F, Cl, and Br) bond energies in fullerene C60 derivatives and other organic compounds are compared.  相似文献   

20.
Sorption of fullerenes C60 and C70 from o-xylene, toluene, and o-dichlorobenzene solutions under static conditions on a sorbent prepared by sublimation of graphite rods was studied. The sorption isotherms of both fullerenes at 25°C were measured.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 345–346.Original Russian Text Copyright © 2005 by Semenov, Arapov, Charykov, Nekrasov, Alekhin, Gerasimov, Seregin.  相似文献   

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