carbon cluster

• 分子结构分类: 有机化合物 - 碳氢化合物 - 饱和烃
• 英文名称: carbon cluster
• 英文别名: graphite；carbon；methane
• 化学式: C₄
• 分子量: 48.044
• InChiKey: GRPUBDDSELRCNH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.54
• 重原子数：
  4
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  carbon cluster 以 neat (no solvent, gas phase) 为溶剂， 生成 甲烷
  参考文献：
  名称：

  Kinetics of C₂ Reactions during High-Temperature Pyrolysis of Acetylene

  摘要：

  The kinetics of C-2 radical reactions during the first stage of acetylene high-temperature pyrolysis was studied by monitoring C, C-2 and C-3 radicals. Quantitative C-2 detection was performed by ring dye laser absorption spectroscopy, C atoms were measured by applying atomic resonance absorption spectroscopy, and C-3 radicals were monitored by their emission using a combination of a spectrograph and an intensified CCD camera system. The experiments were performed behind reflected shock waves and cover the temperature range of 2580-4650 K at pressures around 2 bar. In the first part of the study initial mixtures containing Ar with 5-50 ppm C2H2 were used. In this very low concentration range, rate coefficients for the following four reactions were determined:[GRAPHICS]Furthermore, this experiments indicate that a modification of the JANAF(1) thermodynamic data of either C, C-2 or C-3 seems to be necessary. In the second part, some experiments with relatively high initial acetylene concentrations up to 500 ppm C2H2 in Ar were carried out to check the validity of a more complex mechanism for the acetylene pyrolysis. Finally in a third part, a perturbation study was performed by adding 1000 ppm H-2 to the initial mixtures of Ar with 20 and 50 ppm of C2H2. For the most important perturbation reactions,[GRAPHICS]ificant amounts of dissolved HBr.

  DOI：

  10.1021/jp963373o
• 作为产物：
  描述：

  graphite 生成 carbon cluster
  参考文献：
  名称：

  Reactions of carbon cluster ions with small hydrocarbons

  摘要：

  The ion/molecule reactions of laser-generated carbon cluster ions, C+n (n=3–20), with the neutral hydrocarbons CH4, C2H2, and C2H4 are studied using Fourier transform mass spectrometry. Branching ratios and rate constants are reported for the observed reactions. The reactions and proposed mechanisms are consistent with previous results and suggest a structural change of the cluster ions from linear to cyclic between n=9 and 10. The proposed reaction mechanisms include carbene insertion into both the C–H bonds and the unsaturated C–C bonds of the reactant neutrals. The reactions of the cluster ions with the unsaturated hydrocarbons C2H2 and C2H4 are the first systems in which the cyclic (n≥10) cluster ions are reactive. The results of the reactivity of the carbon cluster ions with the carbon-containing neutrals are discussed in terms of the stability of the clusters toward carbon atom addition and cluster growth. Further evidence is reported for the presence of structural isomers (linear and cyclic) of C+7 including a novel reaction sequence used to remove the linear isomer so that the reactivity of the cyclic isomer with C2H2 may be studied independently.

  DOI：

  10.1063/1.455103

文献信息

• Carbon cluster formation in regenerative sooting plasmas
  作者：Shoaib Ahmad

  DOI：10.1016/s0375-9601(99)00633-7

  日期：1999.10

  Abstract Laboratory formation of large carbon clusters C m ( m ≤10 4 ) in carbonaceous plasmas is studied by using a specially designed ion source. Carbon is introduced into the glow discharge plasma by graphite sputtering. Regenerative sooting plasma creates clustering environment. Velocity spectra of the extracted clusters indicates the mechanisms operating in the soot.

  摘要 利用特殊设计的离子源研究了碳质等离子体中大碳簇C m ( m ≤10 4 ) 的实验室形成。通过石墨溅射将碳引入辉光放电等离子体。再生烟尘等离子体创建聚集环境。提取的簇的速度谱表明在烟尘中运行的机制。
• Carbon cluster cations with up to 84 atoms: structures, formation mechanism, and reactivity
  作者：Gert von Helden、Ming Teh Hsu、Nigel Gotts、Michael T. Bowers

  DOI：10.1021/j100133a011

  日期：1993.8

  Carbon clusters are generated by laser desorption. Mass-selected beams are then pulse injected into an ion chromatography (IC) device. This device temporally and spatially separates the beam into its isomeric components. Arrival time distributions (ATDs) are then measured at the detector. From these distributions, accurate mobilities are obtained for each isomeric component, along with the fractional abundance of each isomer. Different isomer structures are calculated using quantum chemical methods. A Monte Carlo technique uses these structures to obtain accurate theoretical mobilities. Comparison of theory with experiment allows unambiguous structural assignment of the various families of isomers present in the cluster beam. The results indicate that, for carbon cluster cations, linear structures exist up to C-10+. Several families of planar ring systems begin with monocyclic rings (ring I), which first appear at C-7+ and persist beyond C40+. Bicyclic rings (ring II) are first observed at C21+ and persist beyond C40+, followed by tricyclic rings (ring III, initiated at C30+) and tetracyclic rings (ring IV, initiated at C40+). A 3-dimensional family we label as 3-D rings begins at C29+, whose structure is not yet unambiguously assigned. This family never exceeds 5% of the ions at any cluster size. Finally, the first fullerene is observed at C30+, with this family dominating above C50+. The growth pattern of carbon, beginning with C atoms, is shown to be linear --> monocyclic rings --> polycyclic rings --> fullerenes. No graphitic or ''cup'' shaped isomers are observed, eliminating these species as building blocks for fullerenes. Our structural data, when coupled with recently published annealing studies, indicate that fullerenes are formed from isomerization of hot planar ring systems and that monocyclic rings and fullerenes are close in energy between C30+ and C36+ with fullerenes dominating above C36+. Reactions Of C-7+ to C-15+ with O2 and NO are reported and indicate that linear chains are generally much more reactive than rings. Finally, C60 and C70 are made with up to four positive charges but retain the fullerene cage structure.
• Fullerene and nanotube synthesis. plasma spectroscopy studies
  作者：Przemysław Byszewski、Hubert Lange、Andrzej Huczko、Jürgen F. Behnke

  DOI：10.1016/s0022-3697(97)00051-6

  日期：1997.11

  Carbon plasma emission spectoscopy allows the determination of the temperature and density of carbon vapour in the are zone where carbon nanostructures are formed. We focus our attention on carbon nanotube growth which depends on the are current and buffer gas pressure. Our spectral measurements elucidate the general trend governing efficient nanotube formation. (C) 1997 Elsevier Science Ltd.
• Evolution of clusters in energetic heavy ion bombarded amorphous graphite
  作者：M.N. Akhtar、Bashir Ahmad、Shoaib Ahmad

  DOI：10.1016/s0375-9601(97)00581-1

  日期：1997.10

  Carbon clusters have been generated by a novel technique of energetic heavy ion bombardment of amorphous graphite. The evolution of clusters and their subsequent fragmentation under continuing ion bombardment is revealed by detecting various clusters in the energy spectra of the direct recoils emitted as a result of collision between ions and surface constituents. (C) 1997 Published by Elsevier Science B.V.
• Neon matrix ESR investigation of ¹²C⁺₂ and ¹³C⁺₂ : Confirmation of a ⁴Σ⁻_<i>g</i> ground electronic state
  作者：Lon B. Knight、S. T. Cobranchi、E. Earl

  DOI：10.1063/1.454346

  日期：1988.6.15

  The 12C+2 and 13C+2 cation radicals have been isolated in neon matrices by the photoionization of C2(g) generated by the laser vaporization of thin carbon disks. A new procedure of supporting and thermally outgassing such targets for laser vaporization ESR studies in rare gas matrices is described. The ESR results confirm the 4Σ−g ground electronic state assignment for C+2 and provide a valence orbital electronic structure characterization based on the 13C hyperfine structure (hfs). The ESR lines are extremely narrow for a high-spin powder sample and an intense off-angle or ‘‘extra’’ absorption feature exibits unusual hfs. Normally forbidden (ΔMS&gt;1) transitions were detected at low magnetic fields. The magnetic parameters for 13C+2 in a neon matrix at 4 K are: D=3668(3) MHz; g⊥ =2.0018(5); g∥ =2.0023(5); ‖A∥‖ =99.4(8) MHz; and ‖A⊥‖ =95.2(5) MHz.