5,5′-dibromo-N,N′-bisphenyl-2,2′-bipyrrole

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡咯
• 英文名称: 5,5′-dibromo-N,N′-bisphenyl-2,2′-bipyrrole
• 英文别名: 2-Bromo-5-(5-bromo-1-phenylpyrrol-2-yl)-1-phenylpyrrole；2-bromo-5-(5-bromo-1-phenylpyrrol-2-yl)-1-phenylpyrrole
• 化学式: C₂₀H₁₄Br₂N₂
• 分子量: 442.153
• InChiKey: CTGVINPRXAGXNS-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.5
• 重原子数：
  24
• 可旋转键数：
  3
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  9.9
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  5,5′-dibromo-N,N′-bisphenyl-2,2′-bipyrrole 在 正丁基锂 、 四丁基氟化铵 作用下， 以 四氢呋喃 、 正己烷 为溶剂， 反应 62.5h， 生成 N,N′,N″,N′′′′-tetraphenyl-2,2′:5′,2″:5″,2‴-quaterpyrrole
  参考文献：
  名称：

  Molecular Wires using (Oligo)pyrroles as Connecting Units: An Electron Transfer Study

  摘要：

  A series of (oligo)pyrroles featuring redox-active terminal ferrocenyl groups (Fc(2)-((C4H2NPh)-C-c)(n) (4, n = 1; 9, n = 2; 16, n = 3; 20, n = 4)) has been prepared using a Negishi C,C cross-coupling reaction protocol. The bi-, ter-, and quaterpyrrole wire moieties have been built up by C,C cross-coupling reactions of trimethylsilyl-protected pyrrole units in the presence of [Pd(CH2C(CH3)2(P)((C4H9)-C-t)(2))(mu-Cl)](2) as precatalyst. The structural properties of the title compounds were investigated by spectroscopic means and single-crystal X-ray diffraction studies (9, 16, and 20). The influence of the increasing number of N-phenylpyrrole units on the electronic interaction between the iron centers was studied using electrochemistry (cyclic (CV) and square wave voltammetry (SWV)) as well as spectroelectrochemistry (in situ UV/vis/near-IR spectroscopy). With the exception of the diferrocenyl quaterpyrrole 20, the application of [(NBu4)-Bu-n][B(C6F5)(4)] as electrolyte allows the discrete oxidation of the ferrocenyl termini (Delta E degrees' = 450 mV (4), Delta E degrees' = 320 mV (9), Delta E degrees' = 165 mV (16)) in cyclic and square wave voltammograms. However, the iron centers of 20 were oxidized simultaneously, generating dicationic 20(2+). Additionally, one (9) or two (16 and 20) pyrrole-related well-defined reversible one-electron-redox processes were observed. The cyclic voltammetry data reveal that the splitting of the ferrocene-based redox couples, Delta E degrees', decreases with increasing oligopyrrole chain length and, hence, a greater metal-metal distance. The trends in Delta E degrees' with oligopyrrole structure also map to the electronic coupling between the ferrocene moieties, as estimated by spectroelectrochemical UV/vis/near-IR measurements. Despite the fact that there is no direct metal-metal interaction in diferrocenyl quaterpyrrole 20, a large absorption in the near-IR region is observed arising from photoinduced charge transfer from the oligopyrrole backbone to the redox-active ferrocenyl termini. These charge transfer absorptions have also been found in the dicationic oxidation state of the mono-(4), bi- (9), and terpyrroles (16). Within this series of diferrocenyl(oligo)pyrroles this CT band is shifted bathochromically with increasing chain length of the backbone motif.

  DOI：

  10.1021/om4007533
• 作为产物：
  描述：

  1-苯基吡咯 在 N-溴代丁二酰亚胺(NBS) 、 正丁基锂 作用下， 以 四氢呋喃 、 正己烷 、 N,N-二甲基甲酰胺 为溶剂， 反应 16.0h， 生成 5,5′-dibromo-N,N′-bisphenyl-2,2′-bipyrrole
  参考文献：
  名称：

  Molecular Wires using (Oligo)pyrroles as Connecting Units: An Electron Transfer Study

  摘要：

  A series of (oligo)pyrroles featuring redox-active terminal ferrocenyl groups (Fc(2)-((C4H2NPh)-C-c)(n) (4, n = 1; 9, n = 2; 16, n = 3; 20, n = 4)) has been prepared using a Negishi C,C cross-coupling reaction protocol. The bi-, ter-, and quaterpyrrole wire moieties have been built up by C,C cross-coupling reactions of trimethylsilyl-protected pyrrole units in the presence of [Pd(CH2C(CH3)2(P)((C4H9)-C-t)(2))(mu-Cl)](2) as precatalyst. The structural properties of the title compounds were investigated by spectroscopic means and single-crystal X-ray diffraction studies (9, 16, and 20). The influence of the increasing number of N-phenylpyrrole units on the electronic interaction between the iron centers was studied using electrochemistry (cyclic (CV) and square wave voltammetry (SWV)) as well as spectroelectrochemistry (in situ UV/vis/near-IR spectroscopy). With the exception of the diferrocenyl quaterpyrrole 20, the application of [(NBu4)-Bu-n][B(C6F5)(4)] as electrolyte allows the discrete oxidation of the ferrocenyl termini (Delta E degrees' = 450 mV (4), Delta E degrees' = 320 mV (9), Delta E degrees' = 165 mV (16)) in cyclic and square wave voltammograms. However, the iron centers of 20 were oxidized simultaneously, generating dicationic 20(2+). Additionally, one (9) or two (16 and 20) pyrrole-related well-defined reversible one-electron-redox processes were observed. The cyclic voltammetry data reveal that the splitting of the ferrocene-based redox couples, Delta E degrees', decreases with increasing oligopyrrole chain length and, hence, a greater metal-metal distance. The trends in Delta E degrees' with oligopyrrole structure also map to the electronic coupling between the ferrocene moieties, as estimated by spectroelectrochemical UV/vis/near-IR measurements. Despite the fact that there is no direct metal-metal interaction in diferrocenyl quaterpyrrole 20, a large absorption in the near-IR region is observed arising from photoinduced charge transfer from the oligopyrrole backbone to the redox-active ferrocenyl termini. These charge transfer absorptions have also been found in the dicationic oxidation state of the mono-(4), bi- (9), and terpyrroles (16). Within this series of diferrocenyl(oligo)pyrroles this CT band is shifted bathochromically with increasing chain length of the backbone motif.

  DOI：

  10.1021/om4007533

文献信息

• Molecular Wires using (Oligo)pyrroles as Connecting Units: An Electron Transfer Study
  作者：Ulrike Pfaff、Alexander Hildebrandt、Dieter Schaarschmidt、Tobias Rüffer、Paul J. Low、Heinrich Lang

  DOI：10.1021/om4007533

  日期：2013.10.28

  A series of (oligo)pyrroles featuring redox-active terminal ferrocenyl groups (Fc(2)-((C4H2NPh)-C-c)(n) (4, n = 1; 9, n = 2; 16, n = 3; 20, n = 4)) has been prepared using a Negishi C,C cross-coupling reaction protocol. The bi-, ter-, and quaterpyrrole wire moieties have been built up by C,C cross-coupling reactions of trimethylsilyl-protected pyrrole units in the presence of [Pd(CH2C(CH3)2(P)((C4H9)-C-t)(2))(mu-Cl)](2) as precatalyst. The structural properties of the title compounds were investigated by spectroscopic means and single-crystal X-ray diffraction studies (9, 16, and 20). The influence of the increasing number of N-phenylpyrrole units on the electronic interaction between the iron centers was studied using electrochemistry (cyclic (CV) and square wave voltammetry (SWV)) as well as spectroelectrochemistry (in situ UV/vis/near-IR spectroscopy). With the exception of the diferrocenyl quaterpyrrole 20, the application of [(NBu4)-Bu-n][B(C6F5)(4)] as electrolyte allows the discrete oxidation of the ferrocenyl termini (Delta E degrees' = 450 mV (4), Delta E degrees' = 320 mV (9), Delta E degrees' = 165 mV (16)) in cyclic and square wave voltammograms. However, the iron centers of 20 were oxidized simultaneously, generating dicationic 20(2+). Additionally, one (9) or two (16 and 20) pyrrole-related well-defined reversible one-electron-redox processes were observed. The cyclic voltammetry data reveal that the splitting of the ferrocene-based redox couples, Delta E degrees', decreases with increasing oligopyrrole chain length and, hence, a greater metal-metal distance. The trends in Delta E degrees' with oligopyrrole structure also map to the electronic coupling between the ferrocene moieties, as estimated by spectroelectrochemical UV/vis/near-IR measurements. Despite the fact that there is no direct metal-metal interaction in diferrocenyl quaterpyrrole 20, a large absorption in the near-IR region is observed arising from photoinduced charge transfer from the oligopyrrole backbone to the redox-active ferrocenyl termini. These charge transfer absorptions have also been found in the dicationic oxidation state of the mono-(4), bi- (9), and terpyrroles (16). Within this series of diferrocenyl(oligo)pyrroles this CT band is shifted bathochromically with increasing chain length of the backbone motif.