Isobutane

• 分子结构分类: 有机化合物 - 碳氢化合物 - 饱和烃
• 英文名称: Isobutane
• 英文别名: 2-Methylpropane-13C4, 99 atom % 13C, 98% (CP)；2-(113C)methyl(1,2,3-13C3)propane
• 化学式: C₄H₁₀
• 分子量: 62.0794
• InChiKey: NNPPMTNAJDCUHE-JCDJMFQYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 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

• 作为产物：
  描述：

  碘甲烷-13C 在 zeolite HZSM-5 作用下， 生成 甲烷-13C 、 (13C3)丙烷 、 Isobutane 、 2,4-Dimethylpentane
  参考文献：
  名称：

  High-temperature in-situ magic angle spinning NMR studies of chemical reactions on catalysts

  摘要：

  We report in situ magic angle spinning (MAS) studies of chemical reactions on zeolite catalysts in the high-temperature range (573-673 K) used in typical catalytic processes. These studies were carried out using a novel high-temperature MAS probe which is also described in this contribution. The chemical studies reported here were selected based on either earlier studies at lower temperatures or the failure to observe any reactions using probes with lower temperature limits. All reactions were carried out in zeolite HZSM-5. Cracking of ethylene oligomers was studied at 623 K. A product distribution consistent with the formation of a pentacoordinated carbonium ion intermediate was observed which was not seen in a previous investigation at a lower temperature. Furthermore, direct observation of three-coordinate carbenium ion formation during cracking at 523-623 K was achieved. The conversion of methanol to gasoline (MTG) on HZSM-5 was studied with a temperature jump to 623 K. Important differences observed in this study relative to previous investigations at lower temperatures include well-resolved signals for adsorbed vs exogenous (gas phase) methanol and dimethyl ether and a higher yield of aromatics. Two less-reactive methane derivatives were also studied to look for analogies to MTG chemistry. Methyl iodide began reacting on HZSM-5 at ca. 583 K to form light aliphatics and at 623 K was completely consumed to form methane, ethane, and benzene. As was previously observed at lower temperatures, dimethyl sulfide formed trimethylsulfonium ion which proved to be stable even at 673 K in the present contribution.

  DOI：

  10.1021/j100199a052

文献信息

• High-temperature in-situ magic angle spinning NMR studies of chemical reactions on catalysts
  作者：F. Gregory Oliver、Eric J. Munson、James F. Haw

  DOI：10.1021/j100199a052

  日期：1992.10

  We report in situ magic angle spinning (MAS) studies of chemical reactions on zeolite catalysts in the high-temperature range (573-673 K) used in typical catalytic processes. These studies were carried out using a novel high-temperature MAS probe which is also described in this contribution. The chemical studies reported here were selected based on either earlier studies at lower temperatures or the failure to observe any reactions using probes with lower temperature limits. All reactions were carried out in zeolite HZSM-5. Cracking of ethylene oligomers was studied at 623 K. A product distribution consistent with the formation of a pentacoordinated carbonium ion intermediate was observed which was not seen in a previous investigation at a lower temperature. Furthermore, direct observation of three-coordinate carbenium ion formation during cracking at 523-623 K was achieved. The conversion of methanol to gasoline (MTG) on HZSM-5 was studied with a temperature jump to 623 K. Important differences observed in this study relative to previous investigations at lower temperatures include well-resolved signals for adsorbed vs exogenous (gas phase) methanol and dimethyl ether and a higher yield of aromatics. Two less-reactive methane derivatives were also studied to look for analogies to MTG chemistry. Methyl iodide began reacting on HZSM-5 at ca. 583 K to form light aliphatics and at 623 K was completely consumed to form methane, ethane, and benzene. As was previously observed at lower temperatures, dimethyl sulfide formed trimethylsulfonium ion which proved to be stable even at 673 K in the present contribution.