9-methyl-9-fluorenyl carbocation | 20685-25-0

• 分子结构分类: 有机化合物 - 苯类化合物 - 芴
• 英文名称: 9-methyl-9-fluorenyl carbocation
• 英文别名: 9-methyl-9-fluorenyl cation；9-methylfluoren-9-yl cation；9-methylfluoren-9-ylium；9-methyl-fluorenylium；9-Methyl-fluoren-9-yl-kation；9-Methylfluorenyl-(9)-kation
• CAS: 20685-25-0
• 化学式: C₁₄H₁₁
• 分子量: 179.241
• InChiKey: DURYLDFXEMIQAX-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.9
• 重原子数：
  14
• 可旋转键数：
  0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.07
• 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：

  9-methyl-9-fluorenyl carbocation 在 氢溴酸 作用下， 以 various solvent(s) 为溶剂， 生成 9-溴-9-甲基-芴
  参考文献：
  名称：

  Detection and Characterization of a Transient Zwitterion, the 9-Carboxylate-9-fluorenyl Cation, and Its Conjugate Acid¹

  摘要：

  Laser flash photolysis of 9-hydroxy-9-fluorenecarboxylic acid in hexafluoro-2-propanol (HFIP) generates a transient with lambda(max) at 495 nm that reacts with nucleophiles such as methanol and bromide and is insensitive to oxygen. In the presence of 0.15 M trifluoroacetic acid, a different transient with lambda(max) at 560 nm that also reacts with nucleophiles is formed. The 495 and 560 nm species are identified as a zwitterion (the 9-carboxylate-9-fluorenyl cation) and its conjugate acid (the 9-carboxy-9-fluorenyl cation), respectively. The assignment of the zwitterion is supported by the observation of infrared absorptions in the carboxylate region that are quenched by nucleophiles with rate constants similar to those obtained by UV-visible detection. Both the zwitterion and its protonated form are observed at intermediate acid concentrations, leading to an estimate of 1 x 10(-2) M(-1) for the equilibrium constant for the ionization of the 9-carboxy-9-fluorenyl cation in HFIP. Absolute rate constants for reaction of the zwitterion with alcohols, anionic nucleophiles, and substituted aromatics are reported and compared to data for other 9-fluorenyl cations.

  DOI：

  10.1021/ja962066t
• 作为产物：
  描述：

  9-羟基-9-甲基芴 在 高氯酸 、 sodium perchlorate 作用下， 以 水 为溶剂， 生成 9-methyl-9-fluorenyl carbocation
  参考文献：
  名称：

  测定苄基、二苯甲基和芴基碳正离子稳定性的实验和计算：重新审视抗芳香性

  摘要：

  在 I=0.50 (NaClO 4 ) 的 50:50 (v:v) 三氟乙醇/水中形成苄基、二苯甲基和芴基碳正离子的以下 pK R 值确定为 pK R =-log (k HOH [H 2 O]/k H )，其中 k H 是醇酸催化反应形成碳阳离子的二级速率常数，k HOH 是水捕获碳阳离子的二级速率常数

  DOI：

  10.1021/ja00047a010

文献信息

• Stable carbocations. 225. Proton and carbon-13 NMR spectroscopic study of 9-fluorenyl cations
  作者：George A. Olah、G. K. Surya Prakash、Gao Liang、Philip W. Westerman、Klaus Kunde、Jayaraman Chandrasekhar、Paul V. R. Schleyer

  DOI：10.1021/ja00533a030

  日期：1980.6

  of 9-substituted 9-fluorenyl cation were prepared and characterized by 1 H and 13 C NMR spectroscopy. Unsuccessful attempts were made to observe intramolecular interconversion of 9-methyl-9-fluorenyl cation via capped pyramidal ions with ring deuterated and methylated analogues. MINDO/3 calculations on isomeric structures of cyclopentadienyl, indenyl, and fluorenyl cations indicated strongly decreasing

  制备了一系列 9-取代的 9-芴基阳离子，并通过 1 H 和 13 C NMR 光谱进行了表征。曾尝试通过带有氘化环和甲基化类似物的封端锥体离子来观察 9-甲基-9-芴基阳离子的分子内相互转化，但未成功。MINDO/3 对环戊二烯基、茚基和芴基阳离子异构结构的计算表明，由于苯并环化，锥体形式的相对稳定性显着降低。在氘代氟磺酸溶液中，9-甲基-9-芴基 (1-CH 3 ) 和 3.9-二甲基-9-芴基阳离子 (14) 进行氢-氘交换，符合质子化-去质子化机制。
• Stabilities of carbocations in solution. 14. An extended thermochemical scale of carbocation stabilities in a common superacid
  作者：Edward M. Arnett、Thomas C. Hofelich

  DOI：10.1021/ja00347a060

  日期：1983.5
• Lew, Calvin S. Q.; McClelland, Robert A.; Johnston, Linda J., Journal of the Chemical Society. Perkin transactions II, 1994, # 3, p. 395 - 398
  作者：Lew, Calvin S. Q.、McClelland, Robert A.、Johnston, Linda J.、Schepp, Norman P.

  DOI：——

  日期：——
• Experiments and calculations for determination of the stabilities of benzyl, benzhydryl, and fluorenyl carbocations: antiaromaticity revisited
  作者：Tina L. Amyes、John P. Richard、Michael Novak

  DOI：10.1021/ja00047a010

  日期：1992.10

  formation of benzyl, benzhydryl, and fluorenyl carbocations in 50:50 (v:v) trifluoroethanol/water at I=0.50 (NaClO 4 ) were determined as pK R =-log (k HOH [H 2 O]/k H ), where k H is the second-order rate constant for acid-catalyzed reaction of the alcohol to form the carbocation and k HOH is the second-order rate constant for capture of the carbocation by water

  在 I=0.50 (NaClO 4 ) 的 50:50 (v:v) 三氟乙醇/水中形成苄基、二苯甲基和芴基碳正离子的以下 pK R 值确定为 pK R =-log (k HOH [H 2 O]/k H )，其中 k H 是醇酸催化反应形成碳阳离子的二级速率常数，k HOH 是水捕获碳阳离子的二级速率常数
• Detection and Characterization of a Transient Zwitterion, the 9-Carboxylate-9-fluorenyl Cation, and Its Conjugate Acid¹
  作者：C. S. Q. Lew、B. D. Wagner、Mark P. Angelini、E. Lee-Ruff、J. Lusztyk、L. J. Johnston

  DOI：10.1021/ja962066t

  日期：1996.1.1

  Laser flash photolysis of 9-hydroxy-9-fluorenecarboxylic acid in hexafluoro-2-propanol (HFIP) generates a transient with lambda(max) at 495 nm that reacts with nucleophiles such as methanol and bromide and is insensitive to oxygen. In the presence of 0.15 M trifluoroacetic acid, a different transient with lambda(max) at 560 nm that also reacts with nucleophiles is formed. The 495 and 560 nm species are identified as a zwitterion (the 9-carboxylate-9-fluorenyl cation) and its conjugate acid (the 9-carboxy-9-fluorenyl cation), respectively. The assignment of the zwitterion is supported by the observation of infrared absorptions in the carboxylate region that are quenched by nucleophiles with rate constants similar to those obtained by UV-visible detection. Both the zwitterion and its protonated form are observed at intermediate acid concentrations, leading to an estimate of 1 x 10(-2) M(-1) for the equilibrium constant for the ionization of the 9-carboxy-9-fluorenyl cation in HFIP. Absolute rate constants for reaction of the zwitterion with alcohols, anionic nucleophiles, and substituted aromatics are reported and compared to data for other 9-fluorenyl cations.