Casino zwanenburg
在低温固体惰性气体基质中，研究了桥连 α-二酮（Strating-Zwanenburg 反应）的光化学双脱羰基化反应，得到低聚并五苯 (2)、六苯 (3) 和七苯 (4)。使用可见光照射的光分解干净地产生相应的低聚并苯，而不会形成可观察的中间体。这种对高级并苯的合成方法首次允许在相同条件下对其电子吸收和红外光谱特性进行全面的比较研究。此外，该路线使研究这些高级并苯的热和光化学稳定性成为可能，并解决了可追溯到近 70 年前的七苯稳定性问题。发现并苯系列中最大的已知成员在室温下不稳定。此外，所有低聚并苯 2-4 在 185 nm 激发下都会发生光氧化还原反应，导致惰性气体基质中同时形成自由基阳离子和阴离子。低聚并苯的这些极化子状态在它们产生的条件下是稳定的，但在可见光照射下会坍塌为不带电的并苯。
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Synthesis, Stability, and Photochemistry of Pentacene, Hexacene, and Heptacene: A Matrix Isolation Study
The photochemical bisdecarbonylation of bridged alpha-diketones (Strating-Zwanenburg reaction) to give the oligoacenes pentacene (2), hexacene (3), and heptacene (4) is investigated in solid inert gas matrices at cryogenic temperatures. The photodecomposition using visible light irradiation cleanly produces the corresponding oligoacene without formation of observable intermediates. This synthetic approach to the higher acenes allows a comprehensive comparative study of their electronic absorption and infrared spectral properties under identical conditions for the first time. In addition, the route makes it possible to investigate the thermal and photochemical stability of these higher acenes and addresses the problem of heptacene stability which dates back almost 70 years. This largest known member of the acene series is found to be unstable at room temperature. Furthermore, all oligoacenes 2-4 undergo a photoredox reaction upon 185 nm excitation, resulting in the concurrent formation of radical cations and anions in the noble gas matrix. These polaron states of the oligoacenes are stable under the conditions of their generation but collapse to the uncharged acenes upon visible light irradiation.
更新日期：2009-10-14 Источник: https://www.x-mol.com/paper/1475895/t?adv"点击查看英文标题和摘要"
Synthesis, Stability, and Photochemistry of Pentacene, Hexacene, and Heptacene: A Matrix Isolation Study
The photochemical bisdecarbonylation of bridged alpha-diketones (Strating-Zwanenburg reaction) to give the oligoacenes pentacene (2), hexacene (3), and heptacene (4) is investigated in solid inert gas matrices at cryogenic temperatures. The photodecomposition using visible light irradiation cleanly produces the corresponding oligoacene without formation of observable intermediates. This synthetic approach to the higher acenes allows a comprehensive comparative study of their electronic absorption and infrared spectral properties under identical conditions for the first time. In addition, the route makes it possible to investigate the thermal and photochemical stability of these higher acenes and addresses the problem of heptacene stability which dates back almost 70 years. This largest known member of the acene series is found to be unstable at room temperature. Furthermore, all oligoacenes 2-4 undergo a photoredox reaction upon 185 nm excitation, resulting in the concurrent formation of radical cations and anions in the noble gas matrix. These polaron states of the oligoacenes are stable under the conditions of their generation but collapse to the uncharged acenes upon visible light irradiation.
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