α-(4-Methylphenyl)-β-diphenylen-vinylbromid | 14750-03-9

• 分子结构分类: 有机化合物 - 苯类化合物 - 芴
• 英文名称: α-(4-Methylphenyl)-β-diphenylen-vinylbromid
• 英文别名: 9-[bromo-(4-methylphenyl)methylidene]fluorene
• CAS: 14750-03-9
• 化学式: C₂₁H₁₅Br
• 分子量: 347.254
• InChiKey: DPYXSEVPKKQQIE-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.29
• 重原子数：
  22.0
• 可旋转键数：
  1.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.05
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  α-(4-Methylphenyl)-β-diphenylen-vinylbromid 、 4-甲基苯硫酚钠 以 甲醇 为溶剂， 反应 20.0h， 以87%的产率得到9-[(4-methylphenyl)-(4-methylphenyl)sulfanylmethylidene]fluorene
  参考文献：
  名称：

  Substitution of 9-(?-bromo-?-arylmethylene)fluorenes by thiolate ions in aqueous acetonitrile

  摘要：

  DOI：

  10.1002/(sici)1099-1395(199712)10:12<871::aid-poc952>3.0.co;2-r

文献信息

• Photochemical Formation and Electrophilic Reactivities of Vinyl Cations. Influence of Substituents, Anionic Leaving Groups, Solvents, and Excitation Wavelength on Photoheterolysis and Photohomolysis of 1-(p-R-Phenyl)-2-(2,2'-biphenyldiyl)vinyl Halides
  作者：Jan-Maarten Verbeek、Marion Stapper、Erik S. Krijnen、Jan-Dirk van Loon、Gerrit Lodder、Steen Steenken

  DOI：10.1021/j100089a027

  日期：1994.9

  Using product analysis and time-resolved laser flash photolysis techniques, the photochemistry at lambda(exc) approximate to 250 and 310 nm (exe = excitation) of 1-(p-R-phenyl)-2-(2,2'-biphenyldiyl)vinyl halides (R = H, Me, MeO) in methanol and acetonitrile at room temperature was studied. The title compounds undergo photoheterolysis and photohomolysis to give vinyl cations =C+- (carbenium ions) and vinyl radicals =C-.-. The cation: radical ratio increases with electron-donating strength of the substituent R, H < Me < MeO, and with anionic leaving group power of the halide, F- < Cl- < Br- < I-, indicating that the cleavage of the C-X bond to yield cation and halide anion proceeds, in the rate-determining step, by heterolysis and not by homolysis followed by electron transfer in the radical pair. The cation:radical ratio is solvent dependent: e.g., for the vinyl bromide with R = MeO and with lambda(exc) = 308 nm, in CH2Cl2 as solvent, only radical is observed, in comparison with only cation in the much more polar solvent acetonitrile. In acetonitrile-methanol mixtures, the absolute yields of both cation and radical go through a maximum as the methanol content is increased, however, the cation:radical ratio decreases continuously with increasing [MeOH]. For a particular R, the quantum yield for C-X bond cleavage is higher at approximate to 250 than at approximate to 310 nm. Also, the cation:radical ratio is wavelength-dependent: at lambda(exc) approximate to 310 nm there is relatively more heterolysis than at lambda(exc),,, x 250 nm. Rate constants for reaction of the cations with nucleophiles were determined in acetonitrile. Those for reaction of the cation with R = MeO (lifetime in acetonitrile 7 ys) with anionic nucleophiles such as the halides are at the diffusion limit in this solvent, approximate to 2 x 10(10) M(-1) s(-1), whereas those for reaction with water, alcohols, and cyclic ethers are of the order 10(5)-10(6) M(-1) s(-1). The less stabilized cation (R = Me) reacts with alcohols faster by the factor approximate to 100, and it decays in acetonitrile approximate to 100 times more rapidly. Also, 1-(p-a-phenyl)-2-dimethylvinyl bromides (R = H, Me, MeO) were photolyzed in acetonitrile. In the case of R = MeO, the cation p-CH3O-C6H4-C+=CMe(2) was seen (lifetime 770 ns), and its reactivity with alcohols (k values of 10(6)-10(7) M(-1) s(-1)) and halides (k values of 10(10) M(-1) s(-1)) was determined. The vinyl radicals =C-.- react with O-2 to yield vinylperoxyl radicals =C-O-2(.) which have absorption maxima at approximate to 390 nm.