1,4-Dimercaptobenzene dianion

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: 1,4-Dimercaptobenzene dianion
• 英文别名: Benzene-1,4-dithiolate
• 化学式: C₆H₄S₂
• 分子量: 140.23
• InChiKey: WYLQRHZSKIDFEP-UHFFFAOYSA-L

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  8
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  2
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  1,4-Dimercaptobenzene dianion 在 azide radical 作用下， 以 水 为溶剂， 生成 p-Benzodithiyl radical anion
  参考文献：
  名称：

  Spectra, ionization constants, and rates of oxidation of 1,4-dimercaptobenzene and properties of the p-mercaptophenylthiyl and p-benzodithiyl anion radicals

  摘要：

  In basic solution, p-dimercaptobenzene, which is found to have pK(a)'s of 6.0 and 7.7, is rapidly oxidized by azide radical (k = 7.4 x 10(9) M-1 s-1) top-benzodithiyl radical anion, the sulfur analog of p-benzosemiquinone radical anion. This radical has very strong absorption bands at 390 and approximately 700 nm. In acidic solutions, CO2.- abstracts a SH hydrogen atom (k = 3.1 x 10(9) M-1 s-1) to form the p-mercaptophenylthiyl radical, which has absorption maxima at 350 and 585 nm and a pK(a) of 2.7. From measurements of its electron-transfer equilibrium with the resorcinol dianion, the reduction potential of the dithiyl radical has been determined to be 0.33 V vs SHE. This value is 0.37 V below the reduction potential of phenylthiyl radical, indicating that resonance stabilization of approximately 36 kJ/mol results from delocalization of the unpaired spin between the two sulfur atoms. This stabilization energy is, however, approximately 39 kJ/mol less than that for the analogous difference of 0.78 V between the reduction potentials of p-benzosemiquinone anion and phenoxy radicals. At high pH, the dithiyl radical anion decays rapidly in second-order processes (2k = 2.8 x 10(9) M-1 s-1), in contrast to the relatively stable p-benzosemiquinone radical anion, which, because its reduction potential is below that of quinone, is stable toward disproportionation by electron transfer.

  DOI：

  10.1021/j100123a025
• 作为产物：
  描述：

  p-Benzodithiyl radical anion 以 水 为溶剂， 生成 二硫代对苯醌 、 1,4-Dimercaptobenzene dianion
  参考文献：
  名称：

  Spectra, ionization constants, and rates of oxidation of 1,4-dimercaptobenzene and properties of the p-mercaptophenylthiyl and p-benzodithiyl anion radicals

  摘要：

  In basic solution, p-dimercaptobenzene, which is found to have pK(a)'s of 6.0 and 7.7, is rapidly oxidized by azide radical (k = 7.4 x 10(9) M-1 s-1) top-benzodithiyl radical anion, the sulfur analog of p-benzosemiquinone radical anion. This radical has very strong absorption bands at 390 and approximately 700 nm. In acidic solutions, CO2.- abstracts a SH hydrogen atom (k = 3.1 x 10(9) M-1 s-1) to form the p-mercaptophenylthiyl radical, which has absorption maxima at 350 and 585 nm and a pK(a) of 2.7. From measurements of its electron-transfer equilibrium with the resorcinol dianion, the reduction potential of the dithiyl radical has been determined to be 0.33 V vs SHE. This value is 0.37 V below the reduction potential of phenylthiyl radical, indicating that resonance stabilization of approximately 36 kJ/mol results from delocalization of the unpaired spin between the two sulfur atoms. This stabilization energy is, however, approximately 39 kJ/mol less than that for the analogous difference of 0.78 V between the reduction potentials of p-benzosemiquinone anion and phenoxy radicals. At high pH, the dithiyl radical anion decays rapidly in second-order processes (2k = 2.8 x 10(9) M-1 s-1), in contrast to the relatively stable p-benzosemiquinone radical anion, which, because its reduction potential is below that of quinone, is stable toward disproportionation by electron transfer.

  DOI：

  10.1021/j100123a025

文献信息

• Spectra, ionization constants, and rates of oxidation of 1,4-dimercaptobenzene and properties of the p-mercaptophenylthiyl and p-benzodithiyl anion radicals
  作者：D. A. Armstrong、Qun Sun、G. N. R. Tripathi、R. H. Schuler、D. McKinnon

  DOI：10.1021/j100123a025

  日期：1993.5

  In basic solution, p-dimercaptobenzene, which is found to have pK(a)'s of 6.0 and 7.7, is rapidly oxidized by azide radical (k = 7.4 x 10(9) M-1 s-1) top-benzodithiyl radical anion, the sulfur analog of p-benzosemiquinone radical anion. This radical has very strong absorption bands at 390 and approximately 700 nm. In acidic solutions, CO2.- abstracts a SH hydrogen atom (k = 3.1 x 10(9) M-1 s-1) to form the p-mercaptophenylthiyl radical, which has absorption maxima at 350 and 585 nm and a pK(a) of 2.7. From measurements of its electron-transfer equilibrium with the resorcinol dianion, the reduction potential of the dithiyl radical has been determined to be 0.33 V vs SHE. This value is 0.37 V below the reduction potential of phenylthiyl radical, indicating that resonance stabilization of approximately 36 kJ/mol results from delocalization of the unpaired spin between the two sulfur atoms. This stabilization energy is, however, approximately 39 kJ/mol less than that for the analogous difference of 0.78 V between the reduction potentials of p-benzosemiquinone anion and phenoxy radicals. At high pH, the dithiyl radical anion decays rapidly in second-order processes (2k = 2.8 x 10(9) M-1 s-1), in contrast to the relatively stable p-benzosemiquinone radical anion, which, because its reduction potential is below that of quinone, is stable toward disproportionation by electron transfer.