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1.
Wakahara T Matsunaga Y Katayama A Maeda Y Kako M Akasaka T Okamura M Kato T Choe YK Kobayashi K Nagase S Huang H Ata M 《Chemical communications (Cambridge, England)》2003,(23):2940-2941
N@C60 has a lower photochemical reactivity toward disilirane than C60, although N@C60 does not differ from C60 in its thermal reactivity; theoretical calculations reveal that N@C60 and C60 have the same orbital levels and that N@3C60* has a shorter lifetime than 3C60*. 相似文献
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N. F. Goldshleger N. N. Denisov V. A. Nadtochenko M. G. Kaplunov A. V. Kulikov 《Russian Chemical Bulletin》1997,46(12):2032-2035
The interaction of the PPh3-stabilized iridium trihydrido complex H3Ir(PPh3)3 with fullerene C60 under thermal and photochemical excitation was studied under anaerobic conditions. Heating (100 °C) or photolysis by the
visible light of the H3Ir(PPh3)3-C60 650 nm, which are characteristic of the ·2-coordinated C60 in several fullerene-containing metal complexes. The kinetic behavior of the H3Ir(PPh3)3)-C60 system in benzonitrile was investigated using a Nd3+-YAG laser (λ=532 nm). The quenching rate constant determined from the dependence of the effective first-order quenching constant
of C60(T) on the concentration of H3Ir(PPh3)3 is equal to 1.1·109 L mol−1 s−1. The quenching of C60(T) by the iridium hydridophosphine complex follows the reductive mechanism to form a C60 monoanion. The ESR signal with g=2.000 and ΔH=0.17 mT (at room temperature) and characteristic absorption bands in the near-IR region at 940, 1004, and 1076 nm support
the formation of the C60 monoanion during the interaction of the triplet-excited C60 with H3Ir(PPh3)3.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2145–2148, December, 1997. 相似文献
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A convenient, highly efficient, decatungstate-mediated chemical methodology to functionalize fullerenes is demonstrated. A variety of radicals have been generated by the photochemical interaction of tetrabutylammonium decatungstate [(n-Bu4N)4W10O32] and para-substituted toluenes, anisoles, and thioanisole and effectively trapped by the [60]fullerene affording the corresponding 1,2-dihydro[60]fullerene monoadducts in moderate to good yields. 相似文献
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V. V. Gritsenko O. A. D'yachenko N. D. Kushch N. G. Spitsina E. B. Yagubskii N. V. Avramenko M. N. Frolova 《Russian Chemical Bulletin》1994,43(7):1183-1185
Extraction of fullerenes from carbon soot by trichloroethylene has been studied. We have found that C60 forms a solvate with trichloroethylene (C60 · C2HCl3:a=31.31(1);b= 10.156(4);c=10.146(4) Å;V=3228.6 Å3,Z=4,d
calc=1.752 g cm–3, orthorhombic symmetry). Its thermal stability has been studied using TG and DSC. A phase transition of the first order at 167 K has been detected.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1248–1250, July, 1994.The authors are grateful to V. P. Bubnov and I. S. Krainskii for providing them with the samples of fulle-rene-containing carbon soot, and to M. G. Kaplunov and A. V. Zvarykina for assistance in the work.This work was carried out with the financial support of the Russian Foundation for Basic Research, Project Nos. 93-03-18705 and 93-03-5650. 相似文献
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Vivekanantan S. Iyer Kimihiro Yoshimura Volker Enkelmann Rebekka Epsch Jürgen P. Rabe Klaus Müllen 《Angewandte Chemie (International ed. in English)》1998,37(19):2696-2699
At the limits of analytical investigation one finds the nanodimensional C60 graphite segment 1 , which, thanks to its long-chain alkyl substituents, is soluble. Monolayers of 1 on graphite can be characterized by scanning tunneling microscopy. 相似文献
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Shilova EA Lyakhovetsky YI Belokon AI Ponomareva TV Gasanov RG Tumanskii BL Nekrasov YS 《Journal of the American Society for Mass Spectrometry》2011,22(11):2021-2032
Our previous investigations showed that homolytic reactions of C60 with a number of perfluoroorganic and organomercury(II) compounds occurring under electron impact (EI) in the ionization
chamber (IC) of a mass spectrometer could predict the reactivity of C60 towards these compounds in solution or solid state. To expand the scope of this statement, C60 and C70 have been reacted with ketones RCOR1, where R and R1 are alkyl, aryl, benzyl, and CF3, in an IC under EI to yield products of the addition of R· and R1· radicals to the fullerenes, paramagnetic ones being stabilized by hydrogen addition and loss. Experimental evidence in support
of a mechanism involving homolytic dissociation of ketone molecules via superexcited states to afford these radicals that
react with the fullerenes at the IC surface has been obtained. As anticipated, the reactions between C60 and several ketones conducted in solution under UV irradiation have afforded Me-, Ph-, and CF3-derivatives of C60. However, some other products have been identified by mass spectrometry and their formation is reasonably explained. When
decalin has been employed as a solvent, decalinyl derivatives of the fullerene have been found among the products and the
(9-decalinyl)fullerenyl radical has been registered by EPR. Thus, incomplete but reasonable conformity of the results of the
reactions of fullerenes with ketones in an IC under EI with those of the reactions of the same reagents in solution under
UV irradiation has been demonstrated, and the former results can predict the latter ones to a reasonable extent. 相似文献
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Qiwen Teng Jikang Feng Chiachung Sun Michael C. Zerner 《International journal of quantum chemistry》1995,55(1):35-45
Intermediate neglect of differential overlap (INDO ) calculations were used to study two structures of C60NH: one of C2ν, geometry with a bridging NH across the bond between two fused six-membered rings in C60 and the other of Cs geometry with a bridging NH across the bond between a five- and a six-membered ring. We calculated the most stable isomer of C60NH to be of C2ν, symmetry. It was found that the C2ν isomer has a protonated aziridine structure with a bridging C? C bond length of 0.1520 nm. The electronic spectra of both isomers of C60NH were calculated. Comparisons were made with the isoelectronic molecules C60O and C60CH2, cases in which the calculated electronic spectra for the most stable isomers C60O (C2ν) and C60CH2 (C2ν) are in good agreement with recent experimental results. © 1995 John Wiley & Sons, Inc. 相似文献
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Felder D Heinrich B Guillon D Nicoud JF Nierengarten JF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(19):3501-3507
Cyclotriveratrylene (CTV) derivatives substituted with 9 (1) or 18 (2) long alkyl chains have been prepared. Whereas no liquid crystalline behavior has been observed for 1, the CTV derivative 2 has mesomorphic properties. Indeed, at room temperature compound 2 exhibits a nematic phase characterized by cybotactic groups with a local lamello-columnar order. Both CTV derivatives 1 and 2 are able to form supramolecular complexes with C60 in the solid state. In both cases, the 2:1 host-guest species have been obtained as brown compounds. No liquid crystalline behavior was observed for the supramolecular complex [C60 is included in (1)2]. In contrast, observation of the brown product obtained from C60 and the CTV derivative 2 directly after preparation by polarized optical microscopy revealed a fluid birefringent phase at room temperature. When the sample is heated above 70 degrees C, the birefringence of the texture under the microscope disappears and the X-ray diffraction pattern is transformed into a pattern characteristic of a cubic phase. For the first time in thermotropic liquid crystals, the space group of this cubic phase can be assigned as I4(1)32. 相似文献
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Tube C(60)H(60) (5) with fused five-membered rings is more stable than the cage isomer (1) with isolated five-membered rings. Introduction of endo C-H bonds into structure 5 results in further stabilization, but the most stable tube structure with four endo C-H bonds (7) is higher in energy than the most stable cage structure with ten endo C-H bonds (3) by 74.2 kcal/mol. A comprehensive comparison of C(60)H(60) with C(60)F(60) has been made. 相似文献
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Li Yuguo Zhang Xiaodong Li Qingnuan Li Wenxin 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(2):363-364
In this paper water-soluble fullerene derivative C60(OH)xOy was radioiodinated with the iodogen method. The labeling yield was determined by radio-TLC. The effects of pH value, reaction time, temperature and amount of the iodogen on the labeling yield were studied. The labeled product was purified by Sephadex G-25 column chromatography and then the stability of 125I-C60(OH)xOy was examined . The results showed that the radiochemical purity of 125I-C60(OH)xOy solution with benzylalcohol remained 82.7% after 43 hours. 相似文献
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Zandler ME Smith PM Fujitsuka M Ito O D'Souza F 《The Journal of organic chemistry》2002,67(26):9122-9129
Synthesis and physicochemical characterization of a series of molecular triads composed of ferrocene, C(60), and nitroaromatic entities are reported. Electrochemical studies revealed multiple redox processes involving all three redox active ferrocene, C(60), and nitrobenzene entities. Up to eight redox couples within the accessible potential window of o-dichlorobenzene containing 0.1 M (TBA)ClO(4) are observed. A comparison between the measured redox potentials with those of the starting compounds revealed absence of any significant electronic interactions between the different redox entities. The geometric and electronic structure of the triads are elucidated by using ab initio B3LYP/3-21G methods. In the energy-optimized structures, as predicted by electrochemical studies, the first HOMO orbitals are found to be located on the ferrocene entity, while the first LUMO orbitals are mainly on the C(60) entity. The coefficients of the subsequent LUMO orbitals track the observed site of electrochemical reductions of the triads. The photochemical events of the triads are probed by both steady-state and time-resolved techniques. The steady-state emission intensities of the triads and the starting dyad, 2-(ferrocenyl)fulleropyrrolidine, are found to be completely quenched compared to fulleropyrrolidine bearing no redox active substituents. The subpicosecond and nanosecond transient absorption spectral studies revealed efficient charge separation (and rapid charge recombination) in the triads, and this has been attributed to the close spacing of the redox entities of the triad to one another. 相似文献
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Y. Ito 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(1):171-174
The positron density distributions in C60 and K6C60 have been evaluated using the positron lifetime and Doppler-broadening spectroscopy for the annihilation radiation.In C60, positrons are distributed in the interstitial sites between the C60 molecules,which has been demonstrated by measurements of the temperature dependence of the Doppler-broadening of the annihilation radiation. On the other hand, the positron density distribution must be greatly changed in K6C60, because positrons are repelled by Coulomb interactions by the positively charged K atoms. It has been observed that there is an extremely short lifetime and a small Doppler-broadening component for the positron annihilation in K6C60. This component is considered to reflect the positron annihilation inside a C60 molecule. 相似文献
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Bhattacharya S Nayak SK Chattopadhyay S Ghosh K Banerjee M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(5):1257-1262
To improve the selectivity ratio of C70 over C60, a new designer molecule, viz., 3-fluoromesotetraphenylporphyrin (1) has been reported in the present investigations. Fluorescence studies reveal that the Q-absorption band of 1 gets sufficient quenching effect upon addition of both C60 and C70. Binding constants (K) of the C60/1 and C70/1 complexes are estimated to be 580 and 10,800 dm3 mol(-1), respectively. Thus, K(C70)/K(C60) is approximately 19 which is very large and even comparable with other macrocyclic host molecules like calix[5]arene, azacalix[m]arene[n]pyridine, cyclotriveratrylenophane and calixarene bisporphyrin. 1H NMR chemical shift measurements show that the -NH- proton of 1 suffers more shifts in presence of C70 compared to C60. This finding also offers a good support in favor of high K value for C70/1 complex as well as large selectivity ratio of C70 over C60. 相似文献