2,6-di(quinoxalin-5-yl)pyridine | 1429920-08-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二氮杂萘
• 英文名称: 2,6-di(quinoxalin-5-yl)pyridine
• 英文别名: dqxp；5-(6-Quinoxalin-5-ylpyridin-2-yl)quinoxaline；5-(6-quinoxalin-5-ylpyridin-2-yl)quinoxaline
• CAS: 1429920-08-0
• 化学式: C₂₁H₁₃N₅
• 分子量: 335.368
• InChiKey: CNLLQMVEJFWRTG-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.7
• 重原子数：
  26
• 可旋转键数：
  2
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  64.4
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  [Ru(2,6-di(quinolin-8-yl)pyridine)(CH₃CN)₃](PF₆)₂ 、 2,6-di(quinoxalin-5-yl)pyridine 以 乙二醇 为溶剂， 反应 0.33h， 以18%的产率得到[Ru(dqp)(dqxp)](PF₆)₂
  参考文献：
  名称：

  Tuning the Electronics of Bis(tridentate)ruthenium(II) Complexes with Long-Lived Excited States: Modifications to the Ligand Skeleton beyond Classical Electron Donor or Electron Withdrawing Group Decorations

  摘要：

  A series of homoleptic bis(tridentate) [Ru-(L)(2)](2+) (1, 3) and heteroleptic [Ru(L)(dqp)](2+) complexes (2, 4) [L = dqxp (1, 2) or dNinp (3, 4); dqxp = 2,6-di(quinoxalin-5-yl)pyridine, dNinp = 2,6-di(N-7-azaindol-1-yl)pyridine, dqp = 2,6-di(quinolin-8-yl)pyridine) was prepared and in the case of 2 and 4 structurally characterized. The presence of dqxp and dNinp in 1-4 result in anodically shifted oxidation potentials of the Ru3+/2+ couple compared to that of the archetypical [Ru(dqp)(2)](2+) (5), most pronounced for [Ru(dqxp)(2)](2+) (1) with a shift of +470 mV. These experimental findings are corroborated by DFT calculations, which show contributions to the complexes' HOMOs by the polypyridine ligands, thereby stabilizing the HOMOs and impeding electron extraction. Complex 3 exhibits an unusual electronic absorption spectrum with its lowest energy maximum at 382 nm. TD-DFT calculations suggest that this high-energy transition is caused by a localization of the LUMO on the central pyridine fragments of the dNinp ligands in 3, leaving the lateral azaindole units merely spectator fragments. The opposite is the case in 1, where the LUMO experiences large stabilization by the lateral quinorralines. Owing to the differences in LUMO energies, the complexes' reduction potentials differ by about 900 mV [E-1/2(1(2+/1+)) = -1.17 V, E-c,E-p(3(2+/1+)) = -2.06 V vs Fc(+/0)]. As complexes 1-4 exhibit similar excited state energies of around 1.80 V, the variations of the lateral heterocycles allow the tuning of the complexes' excited state oxidation strengths over a range of 900 mV. Complex 1 is the strongest excited state oxidant of the series, exceeding even [Ru(bpy)(3)](2+) by more than 200 mV. At room temperature, complex 3 is nonemissive, whereas complexes 1, 2, and 4 exhibit excited state lifetimes of 255, 120, and 1570 ns, respectively. The excited state lifetimes are thus somewhat shortened compared to that of 5 (3000 ns) but still acceptable to qualify the complexes as photosensitizers in light-induced charge-transfer schemes, especially for those that require high oxidative power.

  DOI：

  10.1021/ic400009m
• 作为产物：
  描述：

  5-溴喹喔啉 、 2,6-bis(trimethylstannyl)pyridine 在 四(三苯基膦)钯 作用下， 以 甲苯 为溶剂， 反应 2.0h， 以59%的产率得到2,6-di(quinoxalin-5-yl)pyridine
  参考文献：
  名称：

  Tuning the Electronics of Bis(tridentate)ruthenium(II) Complexes with Long-Lived Excited States: Modifications to the Ligand Skeleton beyond Classical Electron Donor or Electron Withdrawing Group Decorations

  摘要：

  A series of homoleptic bis(tridentate) [Ru-(L)(2)](2+) (1, 3) and heteroleptic [Ru(L)(dqp)](2+) complexes (2, 4) [L = dqxp (1, 2) or dNinp (3, 4); dqxp = 2,6-di(quinoxalin-5-yl)pyridine, dNinp = 2,6-di(N-7-azaindol-1-yl)pyridine, dqp = 2,6-di(quinolin-8-yl)pyridine) was prepared and in the case of 2 and 4 structurally characterized. The presence of dqxp and dNinp in 1-4 result in anodically shifted oxidation potentials of the Ru3+/2+ couple compared to that of the archetypical [Ru(dqp)(2)](2+) (5), most pronounced for [Ru(dqxp)(2)](2+) (1) with a shift of +470 mV. These experimental findings are corroborated by DFT calculations, which show contributions to the complexes' HOMOs by the polypyridine ligands, thereby stabilizing the HOMOs and impeding electron extraction. Complex 3 exhibits an unusual electronic absorption spectrum with its lowest energy maximum at 382 nm. TD-DFT calculations suggest that this high-energy transition is caused by a localization of the LUMO on the central pyridine fragments of the dNinp ligands in 3, leaving the lateral azaindole units merely spectator fragments. The opposite is the case in 1, where the LUMO experiences large stabilization by the lateral quinorralines. Owing to the differences in LUMO energies, the complexes' reduction potentials differ by about 900 mV [E-1/2(1(2+/1+)) = -1.17 V, E-c,E-p(3(2+/1+)) = -2.06 V vs Fc(+/0)]. As complexes 1-4 exhibit similar excited state energies of around 1.80 V, the variations of the lateral heterocycles allow the tuning of the complexes' excited state oxidation strengths over a range of 900 mV. Complex 1 is the strongest excited state oxidant of the series, exceeding even [Ru(bpy)(3)](2+) by more than 200 mV. At room temperature, complex 3 is nonemissive, whereas complexes 1, 2, and 4 exhibit excited state lifetimes of 255, 120, and 1570 ns, respectively. The excited state lifetimes are thus somewhat shortened compared to that of 5 (3000 ns) but still acceptable to qualify the complexes as photosensitizers in light-induced charge-transfer schemes, especially for those that require high oxidative power.

  DOI：

  10.1021/ic400009m

文献信息

• Tuning the Electronics of Bis(tridentate)ruthenium(II) Complexes with Long-Lived Excited States: Modifications to the Ligand Skeleton beyond Classical Electron Donor or Electron Withdrawing Group Decorations
  作者：Giovanny A. Parada、Lisa A. Fredin、Marie-Pierre Santoni、Michael Jäger、Reiner Lomoth、Leif Hammarström、Olof Johansson、Petter Persson、Sascha Ott

  DOI：10.1021/ic400009m

  日期：2013.5.6

  A series of homoleptic bis(tridentate) [Ru-(L)(2)](2+) (1, 3) and heteroleptic [Ru(L)(dqp)](2+) complexes (2, 4) [L = dqxp (1, 2) or dNinp (3, 4); dqxp = 2,6-di(quinoxalin-5-yl)pyridine, dNinp = 2,6-di(N-7-azaindol-1-yl)pyridine, dqp = 2,6-di(quinolin-8-yl)pyridine) was prepared and in the case of 2 and 4 structurally characterized. The presence of dqxp and dNinp in 1-4 result in anodically shifted oxidation potentials of the Ru3+/2+ couple compared to that of the archetypical [Ru(dqp)(2)](2+) (5), most pronounced for [Ru(dqxp)(2)](2+) (1) with a shift of +470 mV. These experimental findings are corroborated by DFT calculations, which show contributions to the complexes' HOMOs by the polypyridine ligands, thereby stabilizing the HOMOs and impeding electron extraction. Complex 3 exhibits an unusual electronic absorption spectrum with its lowest energy maximum at 382 nm. TD-DFT calculations suggest that this high-energy transition is caused by a localization of the LUMO on the central pyridine fragments of the dNinp ligands in 3, leaving the lateral azaindole units merely spectator fragments. The opposite is the case in 1, where the LUMO experiences large stabilization by the lateral quinorralines. Owing to the differences in LUMO energies, the complexes' reduction potentials differ by about 900 mV [E-1/2(1(2+/1+)) = -1.17 V, E-c,E-p(3(2+/1+)) = -2.06 V vs Fc(+/0)]. As complexes 1-4 exhibit similar excited state energies of around 1.80 V, the variations of the lateral heterocycles allow the tuning of the complexes' excited state oxidation strengths over a range of 900 mV. Complex 1 is the strongest excited state oxidant of the series, exceeding even [Ru(bpy)(3)](2+) by more than 200 mV. At room temperature, complex 3 is nonemissive, whereas complexes 1, 2, and 4 exhibit excited state lifetimes of 255, 120, and 1570 ns, respectively. The excited state lifetimes are thus somewhat shortened compared to that of 5 (3000 ns) but still acceptable to qualify the complexes as photosensitizers in light-induced charge-transfer schemes, especially for those that require high oxidative power.