Expanded Hexapyrrolohexaazacoronenes. Near-Infrared Absorbing Chromophores with Interrupted Peripheral Conjugation

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• 作者：El偶bieta Go艅ka ; Piotr J. Chmielewski ; Tadeusz Lis ; Marcin St臋pie艅
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：November 19, 2014
• 年：2014
• 卷：136
• 期：46
• 页码：16399-16410
• 全文大小：700K
• ISSN：1520-5126

文摘

A family of azacoronenes containing up to two saturated bridges at the periphery was synthesized from substituted hexapyrrolylbenzenes using a two-step condensation鈥揳romatization procedure. The introduction of peripheral bridges provides access to nonplanar, sterically crowded systems that display complex reactivity patterns, involving stereospecific aromatization of bridges and nucleophile additions. Despite the interrupted conjugation on the periphery, the new azacoronenes have easily accessible higher oxidation levels, and a quadruply charged species was chemically generated by reaction with SbCl₅. These oxidized species show extensive 蟺-electron conjugation and are efficient UV鈥搗is鈥揘IR absorbers, active up to ca. 2400 nm. Interruption of peripheral conjugation is shown to induce a tendency toward biradicaloid electron configurations in doubly oxidized species.