Synthesis and characterization of an unexpected mechanochromicbistricyclic aromatic ene

Publication date: Available online 8 February 2020Source: Chinese Chemical LettersAuthor(s): Gui-Fei Huo, Qian Tu, Xiao-Li Zhao, Xueliang Shi, Hai-Bo YangAbstractAn unexpected bistricyclic aromatic ene AF was synthesized in a tin(II) chloride-mediated reductive aromatization reaction. The obtained AF showed a highly overcrowded structural conformation as revealed by X-ray crystallography. Interestingly, AF exhibited reversible high-contrast mechanochromism and thermochromism between pale and red color. The obvious chromism is likely ascribed to the conformation transformation and trace amount of diradical species formation upon stimulus.Graphical abstractBistricyclic aromatic ene AF was coincidentally synthesized in a SnCl2-mediated reductive aromatization reaction through a carbocation induced 1,2-migration. AF exhibited interesting mechanochromic property and its twisted conformation could be further thermally populated to a triplet excited state.
Source: Chinese Chemical Letters - Category: Chemistry Source Type: research