2-(2-hydroxyphenyl)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole | 111997-60-5

• 分子结构分类: 有机化合物 - 有机氮化合物
• 英文名称: 2-(2-hydroxyphenyl)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole
• 英文别名: 2-(5-(4-(Dimethylamino)phenyl)-1,3,4-oxadiazol-2-yl)phenol；2-[5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-yl]phenol
• CAS: 111997-60-5
• 化学式: C₁₆H₁₅N₃O₂
• 分子量: 281.314
• InChiKey: IEAVALFYMJGXMA-UHFFFAOYSA-N

物化性质

• 熔点：
  202-203 °C(Solv: methanol (67-56-1))
• 沸点：
  472.6±55.0 °C(Predicted)
• 密度：
  1.246±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.8
• 重原子数：
  21
• 可旋转键数：
  3
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.12
• 拓扑面积：
  62.4
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为产物：
  描述：

  水杨酰肼 在 氯化亚砜 、 sodium carbonate 作用下， 以 水 、 甲苯 为溶剂， 反应 2.0h， 生成 2-(2-hydroxyphenyl)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole
  参考文献：
  名称：

  Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

  摘要：

  Luminescent properties of several ortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole were studied in solvents of different polarity and protolytic ability and compared with the analogous derivatives of 1,3-oxazole, studied by us earlier. Evaluations of rate constants for the excited state intramolecular proton transfer (ESIPT) reaction and radiationless degradation of the energy of electronic excitation in the ESIPT reaction product, phototautomer form, were made on the basis of fluorescence quantum yields and fluorescence kinetic measurements. The proton phototransfer reaction is the most efficient primary photoprocess in the examined series of compounds. With rate constants of 10(11)-10(12) s(-1) it exceeds the rates of other primary photophysical processes in these molecules by up to 2-3 orders of magnitude. A connection between the rate of the ESIPT reaction and the electron density redistribution on electronic excitation was revealed for the molecules under study. The electron donor substituents in 5-phenyl decrease the proton phototransfer rate constant up to complete inhibition of the ESIPT process in the case of the dimethylamino derivative of the oxazole series, whereas the electron acceptor substituents must accelerate this reaction. The determining role of the excited state increase of the proton donor group acidity was assumed on the basis of experimental data and quantum chemical calculations. The temperature investigations showed that the ESIPT reaction in the series of ortho-hydroxy derivatives of 2,5-diphenyloxazole and 2,5-diphenyl-1,3,3-oxadiazole has a very low activation barrier. However, the radiationless processes in the phototautomer form are characterized by the presence of a certain barrier in both examined series. A dependence of the radiationless dissipation rate in the phototautomer form on the excited state redistribution of the electron density in it was also found. The more efficient is, the charge transfer from the ortho-phenolate fragment to the protonated heterocycle and the rest of the molecule, the more efficient are the radiationless losses. It was revealed that structural changes, which prevent the mentioned movement of electron density, result in an increase in the fluorescence efficiency of the phototautomer form and, hence, also to an increase in the total fluorescence quantum yield of the ESIPT molecule. Copyright (C) 2000 John Wiley & Sons, Ltd.

  DOI：

  10.1002/1099-1395(200005)13:5<253::aid-poc238>3.0.co;2-d

文献信息

• Santus, Maria, Liebigs Annalen der Chemie, 1988, p. 179 - 182
  作者：Santus, Maria

  DOI：——

  日期：——
• KUMAR, ATUL;SINGH, S.;VERMA, M.;SAXENA, A. K.;SHANKER, K., INDIAN J. PHARM. SCI., 49,(1987) N 6, 201-204
  作者：KUMAR, ATUL、SINGH, S.、VERMA, M.、SAXENA, A. K.、SHANKER, K.

  DOI：——

  日期：——
• SANTUS, MARIA, LIEBIGS ANN. CHEM.,(1988) N 2, 179-182
  作者：SANTUS, MARIA

  DOI：——

  日期：——
• Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole
  作者：Andrey O. Doroshenko、Eugene A. Posokhov、Alla A. Verezubova、Lydia M. Ptyagina

  DOI：10.1002/1099-1395(200005)13:5<253::aid-poc238>3.0.co;2-d

  日期：2000.5

  Luminescent properties of several ortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole were studied in solvents of different polarity and protolytic ability and compared with the analogous derivatives of 1,3-oxazole, studied by us earlier. Evaluations of rate constants for the excited state intramolecular proton transfer (ESIPT) reaction and radiationless degradation of the energy of electronic excitation in the ESIPT reaction product, phototautomer form, were made on the basis of fluorescence quantum yields and fluorescence kinetic measurements. The proton phototransfer reaction is the most efficient primary photoprocess in the examined series of compounds. With rate constants of 10(11)-10(12) s(-1) it exceeds the rates of other primary photophysical processes in these molecules by up to 2-3 orders of magnitude. A connection between the rate of the ESIPT reaction and the electron density redistribution on electronic excitation was revealed for the molecules under study. The electron donor substituents in 5-phenyl decrease the proton phototransfer rate constant up to complete inhibition of the ESIPT process in the case of the dimethylamino derivative of the oxazole series, whereas the electron acceptor substituents must accelerate this reaction. The determining role of the excited state increase of the proton donor group acidity was assumed on the basis of experimental data and quantum chemical calculations. The temperature investigations showed that the ESIPT reaction in the series of ortho-hydroxy derivatives of 2,5-diphenyloxazole and 2,5-diphenyl-1,3,3-oxadiazole has a very low activation barrier. However, the radiationless processes in the phototautomer form are characterized by the presence of a certain barrier in both examined series. A dependence of the radiationless dissipation rate in the phototautomer form on the excited state redistribution of the electron density in it was also found. The more efficient is, the charge transfer from the ortho-phenolate fragment to the protonated heterocycle and the rest of the molecule, the more efficient are the radiationless losses. It was revealed that structural changes, which prevent the mentioned movement of electron density, result in an increase in the fluorescence efficiency of the phototautomer form and, hence, also to an increase in the total fluorescence quantum yield of the ESIPT molecule. Copyright (C) 2000 John Wiley & Sons, Ltd.