7-cis β-carotene | 83601-92-7

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 异戊烯醇脂质
• 英文名称: 7-cis β-carotene
• 英文别名: 7-cis-β-carotene；(7Z)-β,β-carotene；β-Caroten；1,3,3-trimethyl-2-[(1Z,3E,5E,7E,9E,11E,13E,15E,17E)-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene
• CAS: 83601-92-7
• 化学式: C₄₀H₅₆
• 分子量: 536.885
• InChiKey: OENHQHLEOONYIE-JHIHEJNFSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  13.5
• 重原子数：
  40
• 可旋转键数：
  10
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  7-cis β-carotene 反应 1.0h， 生成 7,13-di-cis-β-carotene 、 b,b-Carotene, 15-cis- 、 b,b-Carotene, 15-cis-
  参考文献：
  名称：

  Triplet-sensitized and thermal isomerization of all-trans, 7-cis, 9-cis, 13-cis and 15-cis isomers of .beta.-carotene: configurational dependence of the quantum yield of isomerization via the T1 state

  摘要：

  The products of triplet-sensitized photoisomerization (excitation at 337 nm of the sensitizer, anthracene) and thermal isomerization of beta-carotene in n-hexane, starting from the all-trans, 7-cis, 9-cis, 13-cis, and 15-cis isomers, were analyzed by HPLC. Direct photoisomerization (excitation at 488 and 337 nm) was also examined for comparison. Three different isomerization patterns were found in both triplet-sensitized and thermal isomerization: pattern A, cis to trans isomerization around each cis bond; pattern B, trans to cis isomerization in the central part of the conjugated chain; and pattern C, cis to another cis isomerization. In the T1 state, the pattern A isomerization was predominant even for the peripheral-cis (7-cis and 9-cis) isomers and its efficiency was extremely high for the central-cis (13-cis and 15-cis) isomers. In the S0 state, the pattern B isomerization, instead, was predominant for the peripheral-cis isomers, and the pattern A isomerization was predominant only for the central-cis isomers. The quantum yields of triplet-sensitized isomerization (decrease of the starting isomer per triplet species generated) were determined to be as follows: all-trans, 0.04; 7-cis, 0.12; 9-cis, 0.15; 13-cis, 0.87; and 15-cis, 0.98. In direct photoisomerization, the quantum yield of isomerization at 488-nm (337 nm) excitation was 4 (3) orders of magnitude lower than the above values, the relative values among the isomers being similar to the above. Further, the overall isomerization patterns of direct photoexcitation were similar to those of triplet-sensitized isomerization, supporting the idea that isomerization takes place via the T1 state even in the case of direct photoexcitation. Carbon-carbon pi-bond orders of model polyenes in the T1 and S0 states were calculated by using the Pariser-Parr-Pople CI theory; bond lengths were optimized by using a bond order-bond length relationship. Isomerization characteristics in the T1 and S0 states observed were discussed based on the results of the calculations.

  DOI：

  10.1021/j100172a016

文献信息

• Triplet-sensitized and thermal isomerization of all-trans, 7-cis, 9-cis, 13-cis and 15-cis isomers of .beta.-carotene: configurational dependence of the quantum yield of isomerization via the T1 state
  作者：Michitaka Kuki、Yasushi Koyama、Hiroyoshi Nagae

  DOI：10.1021/j100172a016

  日期：1991.9

  The products of triplet-sensitized photoisomerization (excitation at 337 nm of the sensitizer, anthracene) and thermal isomerization of beta-carotene in n-hexane, starting from the all-trans, 7-cis, 9-cis, 13-cis, and 15-cis isomers, were analyzed by HPLC. Direct photoisomerization (excitation at 488 and 337 nm) was also examined for comparison. Three different isomerization patterns were found in both triplet-sensitized and thermal isomerization: pattern A, cis to trans isomerization around each cis bond; pattern B, trans to cis isomerization in the central part of the conjugated chain; and pattern C, cis to another cis isomerization. In the T1 state, the pattern A isomerization was predominant even for the peripheral-cis (7-cis and 9-cis) isomers and its efficiency was extremely high for the central-cis (13-cis and 15-cis) isomers. In the S0 state, the pattern B isomerization, instead, was predominant for the peripheral-cis isomers, and the pattern A isomerization was predominant only for the central-cis isomers. The quantum yields of triplet-sensitized isomerization (decrease of the starting isomer per triplet species generated) were determined to be as follows: all-trans, 0.04; 7-cis, 0.12; 9-cis, 0.15; 13-cis, 0.87; and 15-cis, 0.98. In direct photoisomerization, the quantum yield of isomerization at 488-nm (337 nm) excitation was 4 (3) orders of magnitude lower than the above values, the relative values among the isomers being similar to the above. Further, the overall isomerization patterns of direct photoexcitation were similar to those of triplet-sensitized isomerization, supporting the idea that isomerization takes place via the T1 state even in the case of direct photoexcitation. Carbon-carbon pi-bond orders of model polyenes in the T1 and S0 states were calculated by using the Pariser-Parr-Pople CI theory; bond lengths were optimized by using a bond order-bond length relationship. Isomerization characteristics in the T1 and S0 states observed were discussed based on the results of the calculations.