Heptacene (1) was generated by the photodecarbonylation of 7,16-dihydro-7,16-ethanoheptacene-19,20-dione (2) in a polymer matrix using a UV-LED lamp (395 +/- 25 nm). Compound 1 showed a long wavelength absorption band extending from 600 to 825 nm (lambdamax approximately 760 nm) and was found to be stable up to 4 h in the polymer matrix. However, irradiation of a solution of 2 in toluene produced only
Heptacene: Increased Persistence of a 4<i>n</i>+2 π-Electron Polycyclic Aromatic Hydrocarbon by Oxidation to the 4<i>n</i> π-Electron Dication
作者:Ralf Einholz、Holger F. Bettinger
DOI:10.1002/anie.201209722
日期:2013.9.9
unexpectedly stable dication: Heptacene (a 4n+2 π‐electron compound) is so highly reactive that it cannot be isolated. Its dication (a 4n π‐electron compound) can be obtained from heptacene dimers/oligomers in sulfuric acid at room temperature and can be kept for more than one year in the absence of oxygen. (See picture for the UV/Vis‐NIR spectra of the dications of tetracene to heptacene.)
出乎意料的稳定指示:庚并烯(一种4 n + 2π电子化合物)具有很高的反应活性,因此无法分离。其双阳离子(4 Ñ π电子化合物)可从七苯二聚体/硫酸的低聚物在室温下获得,并且可以在不存在氧的可保存一年以上。(参见图片以并四苯为庚并的指示剂的UV / Vis-NIR光谱。)