共查询到19条相似文献,搜索用时 83 毫秒
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中性氧化铝用于碳—60,碳—70柱分离的探讨 总被引:1,自引:0,他引:1
1 引言 自90年实现实验室合成C_(60)/C_(70)以来,碳原子簇化学引起世界各国科学家的广泛兴趣,纷纷开展与其相关的各项研究。由电阻加热法、电孤法产生的烟灰经过甲苯(或苯)抽提便可得到C_(60)/C_(70)混合溶液,但其大量分离却很困难。Hawkins等用苯基甘氨酸做基底的HPLC方法和Jinno等用多取代苯基修饰的二氧化硅作固 相似文献
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C60和C70的制备,分离及物化性质研究 总被引:4,自引:1,他引:4
Kr(a|¨)tschmer,Huffman和他们的同事首先报道了制备C_(60)和C_(70)混合物的方法,我们利用Kr(a|¨)tschmer方法,但简化了装置合成了C_(60)和C_(70)合成方法基本原理为:当强电流使 相似文献
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球状碳:C60及C70 总被引:3,自引:0,他引:3
本文简要介绍第三种形式的碳——C_(60)及C_(70)的发现过程、实验室制备、结构与光谱特征及形成球状Cn分子的一般原则;在最后部分,扼要提出了C_(60)的应用和研究前景。 相似文献
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C60和C70的分子及晶体结构 总被引:1,自引:0,他引:1
本文较详细地介绍了C60、C70的各种光谱、波谱、X射线衍射结果及C60、C70单晶体的培养方法,说明了C60、C70的分子构型及晶体结构和相变特点。 相似文献
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富勒烯碳-60,碳-70的电化学研究进展 总被引:1,自引:0,他引:1
短短的几年,随着各种物理与化学研究方法的相继介入,以C_(60)和C_(70)为代表的富勒烯研究取得了令人瞩目的成就。跟踪最新进展,引文41篇,本文就其电化学方面的研究工作做了系统的综述。 相似文献
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Toshihiko Osaki Toshiyuki Tanaka Yutaka Tai 《Reaction Kinetics and Catalysis Letters》2003,79(2):319-324
Temperature-programmed reaction (TPR) of C60 and C70 with H2 was carried out on nickel in order to investigate the thermal stability of the fullerenes in the catalytic hydrogenation.
The TPR profiles showed two methanation peaks and the corresponding weight decrease above 420°C, indicating the hydrogenolysis
to CH4.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Microwave-assisted extraction (MAE) was examined as an alternative to the traditional Soxhlet method of extracting C60 and C70 from fullerene soot. MAE of 0.20 g of fullerene soot with 95:5 toluene–acetonitrile yielded greater than 7.8 mg of C60 and greater than 0.54 mg of C70 in 4 min with no further increase in yield after 30 min of irradiation. By comparison, exhaustive Soxhlet extraction of the same size sample with the same solvent yielded 7.1 mg of C60 and 0.58 mg of C70 in 340 min. Reextraction by MAE of soot initially extracted by Soxhlet increased the yield of Soxhlet alone. Although MAE was limited to less than 0.5-g sample per extraction vessel, multiple samples were extracted with minimal increased extraction time and no reduction in the amount of material recovered. 相似文献
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Natalia V. Avramenko M. V. Korobov Aksana M. Parfenova P. A. Dorozhko Natalia A. Kiseleva P. V. Dolgov 《Journal of Thermal Analysis and Calorimetry》2006,84(1):259-262
In an effort to improve
understanding of dissolution behaviour of fullerenes and their simple chemical
derivatives the binary systems of C60, C70
and the piperazine monoadduct of [60] fullerene C60
N2C4H8
with a series of aromatic solvents have been studied by means of DSC. In certain
systems solid solvates have been found to be the thermodynamically stable
phases relative to saturated solution at room temperature. Identified solid
solvates were characterized by their compositions, temperatures and enthalpies
of incongruent melting transitions. The regularities in thermodynamic stability
of the solvated crystals have been discussed along with dissolution properties
of fullerenes and the derivative. Certain correlations have been observed. 相似文献
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Dr. Zhe Liu Dr. Wenru Song Shaojie Yang Prof. Dr. Chengshan Yuan Prof. Dr. Zitong Liu Prof. Dr. Hao-Li Zhang Prof. Dr. Xiangfeng Shao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(20):e202200306
Exploration of π-conjugated polycycles, particularly those have π-frameworks spread over the three-dimensional space, is essential in materials science and synthetic chemistry as these chemical entities possess featured optoelectronic properties and supramolecular assembly. Herein, the bowl-shaped trichalcogenasumanenes are fused onto three branches of triptycene through pyrazine units, affording waterwheel-like three-dimensional polycycles 4 a/4 b . Because the three branches on 4 a/4 b are chemically equal, the molecular orbitals of 4 a/4 b show degenerate feature that results in the strong UV-Vis absorbance at steady state. 4 a/4 b exhibit photo-induced charge-separation and subsequent charge-redistribution at transient state, leading to excited state absorption in NIR-II window (1165–1400 nm). 4 a/4 b are excellent fullerene receptors, and they form 1 : 1 host-guest complexes with C60/C70 as proved by spectroscopic titrations and single crystal structure analysis. Moreover, 4 a/4 b show much stronger affinity toward C70 than C60. Consequently, 4 a/4 b are able to separate C60 and C70 from their mixture, giving the purity of C60 up to 99.5 %. 相似文献
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通过伯氨氢原子在一定条件下发生α-消除得到活性中间体氮烯的方法,合成了水溶性五加成C60二甘肽衍生物,产率12.3%。 相似文献
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A. S. Lobach N. F. Goldshleger M. G. Kaplunov A. V. Kulikov 《Russian Chemical Bulletin》1996,45(1):93-98
Radical anions C70- and C70 2- were obtained in vacuo by the reaction of I-amino3-propanol (AP) and 1,5-diaminopentane (DAP) with fullerene C70. The radical anions were identified by visible/near IR (X = I372 and I172 nm, respectively) and ESR spectroscopies. The temperature dependences of the ESR spectra were studied for the C60-AP, C70-AP, and C70-DAP systems. At low temperatures (I5-45 K), the ESR spectrum for C60 is close to that for species with axial symmetry of theg-factor (q| = 2.000 and g, = I.995). The anisotropy of theg-factor is averaged, when the temperature increases. At T > I48 K the averaged line is broadened, and the sharp signal with g = 2.0001 overlaps this broad line. The intensity of the narrow line increases, when the temperature increases. The ESR spectrum observed in the C70-AP system at I2.5 K may be tentatively described as a superposition of two ESR spectra, namely, the ESR spectra of a radical with g| = 2.0042 and g, = 2.0015 (presumably a radical cation) and of C70
– with q| = 2.000 and g = I.994. The spectra of the sample in which C70 is present mainly as C70
2– exhibit only a line with g = 2.0004.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. I, pp. 103–108, January, 1996. 相似文献
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Cerium oxide (CeO2) was tested as a packing material in liquid chromatography for the separation of C60 and C70 fullerenes. The separation of C60 and C70 fullerenes could be achieved within 20 min by using pure n-hexane as the mobile phase. Furthermore, some higher fullerenes could also be separated in less than 40 min. The peak area was reproducible to a large extent. The separation of fullerenes by liquid chromatography on CeO2 is shown to be an effective method for their isolation in large amounts. The column efficiency of the CeO2 column was compared with commercial silica gel and ODS columns. The main advantage of the CeO2 column is its ability to separate large amounts of fullerenes (C60 and C70) in toluene. 相似文献
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The influence of temperature on the retention and separation of C60 and C70 fullerenes was studied under HPLC conditions.
Particularly, chromatographic experiments were conducted using moderate carbon loaded octadecylsilica stationary phase and
homologous series of n-alkanes including n-pentane, n-hexane and n-heptane as the mobile phases. All studies were performed across wide range of subambient temperature from −80 to +20 °C.
From practical point of view the best chromatographic conditions for baseline separation of the components of interest were
selected. The retention of analytes was strongly affected by temperature and below minus 30 °C strong deviation from van't
Hoff behavior was observed. To explore this phenomenon selected thermodynamic parameters including changes of enthalpy (ΔHo) and changes of entropy (ΔSo) were estimated. Positive values of the ΔHo and ΔSo at low temperature region may indicate the lack of the interaction with the stationary phase ligands. A possible retention
mechanism at different temperatures for C60 and C70 molecules has been discussed. 相似文献