*Article* **Two-Step Synthesis, Structure, and Optical Features of a Double Hetero[7]helicene**

**Mohamed S. H. Salem 1,2, Ahmed Sabri 1, Md. Imrul Khalid 1, Hiroaki Sasai 1,3 and Shinobu Takizawa 1,\***

<sup>1</sup> SANKEN, Osaka University, Ibaraki-shi, Osaka 567-0047, Japan


**Abstract:** A novel double aza-oxa[7]helicene was synthesized from the commercially available *N1*,*N4*-di(naphthalen-2-yl)benzene-1,4-diamine and *p*-benzoquinone in two steps. Combining the acid-mediated annulation with the electrochemical sequential reaction (oxidative coupling and dehydrative cyclization) afforded this double hetero[7]helicene. Moreover, the structural and optical features of this molecule have been studied using X-ray crystallographic analysis, and the absorption and emission behaviors were rationalized based on DFT calculations.

**Keywords:** polycyclic aromatic hydrocarbon; double hetero[7]helicene; short-step synthesis; electrochemical cross-coupling; nucleus-independent chemical shift
