南开大学王小野团队研究了乙酰二烯的非苯系纳米石墨烯的两步合成及π-扩展。 相关研究成果于2021年3月30日发表于国际一流学术期刊《美国化学会杂志》。

乙酰二烯（APD）是芘的一种非苯类非取代异构体，具有与芘不同的电子性质，但自1956年首次合成以来，由于合成和进一步衍生化的困难，人们对其研究甚少。

该文中，研究人员重温了这一久负盛名的化合物，并开发了一种新的两步合成路线，以在克级上有效地获得APD。理论和实验表征阐明了APD与其苯并异构体芘相比的独特性质，特别是揭示了APD具有窄光学禁带的偶极结构。研究人员首次证明了APD的功能化，提供了双溴化APD作为进一步π-扩展的关键前体。

为了验证这一概念，研究人员构建了π扩展的APD和环三聚体纳米石墨烯（C48H24），为低HOMO-LUMO间隙的非苯类纳米石墨烯开辟了新的途径。

附：英文原文

Title: Revisiting Acepleiadylene: Two-Step Synthesis and π-Extension toward Nonbenzenoid Nanographene

Author: Pengcai Liu, Xing-Yu Chen, Jiawen Cao, Lukas Ruppenthal, J. Michael Gottfried, Klaus Müllen, Xiao-Ye Wang

Issue&Volume: March 30, 2021

Abstract: Acepleiadylene (APD), a nonbenzenoid nonalternant isomer of pyrene, exhibits different electronic properties from pyrene, but has been rarely studied since its first synthesis in 1956, probably due to the difficulties in synthesis and further derivatization. In this work, we revisited this long-known compound and developed a new two-step synthetic route to efficiently access APD on the gram scale. Theoretical and experimental characterizations elucidated the unique properties of APD as compared with its benzenoid isomer pyrene, particularly revealing its dipolar structure with a narrow optical gap. The functionalization of APD was demonstrated for the first time, providing doubly brominated APD as a key precursor for further π-extension. As a proof of concept, a π-extended APD and a cyclotrimer nanographene (C48H24) were constructed, opening up new avenues to nonbenzenoid nanographenes with low HOMO–LUMO gaps.

DOI: 10.1021/jacs.1c01826

Source: https://pubs.acs.org/doi/10.1021/jacs.1c01826