Double Heterohelicenes Composed of Benzo[ b]- and Dibenzo[ b, i]phenoxazine: A Comprehensive Comparison of Their Electronic and Chiroptical Properties

Daisuke Sakamaki; Shunya Tanaka; Katsuki Tanaka; Mayu Takino; Masayuki Gon; Kazuo Tanaka; Takashi Hirose; Daichi Hirobe; Hiroshi M Yamamoto; Hideki Fujiwara

doi:10.1021/acs.jpclett.1c02896

Double Heterohelicenes Composed of Benzo[ b]- and Dibenzo[ b, i]phenoxazine: A Comprehensive Comparison of Their Electronic and Chiroptical Properties

J Phys Chem Lett. 2021 Sep 30;12(38):9283-9292. doi: 10.1021/acs.jpclett.1c02896. Epub 2021 Sep 20.

Authors

Daisuke Sakamaki¹, Shunya Tanaka¹, Katsuki Tanaka¹, Mayu Takino¹, Masayuki Gon², Kazuo Tanaka², Takashi Hirose^{3

4}, Daichi Hirobe^{4

5

6}, Hiroshi M Yamamoto^{5

6}, Hideki Fujiwara¹

Affiliations

¹ Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Naka-ku, Sakai, Osaka 599-8531, Japan.
² Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
³ Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
⁴ PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
⁵ Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.
⁶ SOKENDAI (Graduate University for Advanced Studies), Myodaiji, Okazaki 444-8585, Japan.

PMID: 34542299
DOI: 10.1021/acs.jpclett.1c02896

Abstract

Heterohelicenes are potential materials in molecular electronics and optics because of their inherent chirality and various electronic properties originating from the introduced heteroatoms. In this work, we comprehensively investigated two kinds of double NO-hetero[5]helicenes composed of 12H-benzo[b]phenoxazine (BPO) and 13H-dibenzo[b,i]phenoxazine (DBPO). These helicenes exhibit good electron-donor properties reflecting the electron-rich character of their monomers and were demonstrated to work as p-type semiconductors. The enantiomers of these helicenes show the largest class of dissymmetry factors for circularly polarized luminescence (CPL) (|g_CPL| > 10^-2) among helicenes reported to date. Interestingly, the signs of CPL are opposite for BPO and DBPO double helicenes of the same helicity. The origin of the large g_CPL values and the inversion of the CPL sign was addressed by analysis of the transition electronic dipole moments and transition magnetic dipole moments based on TD-DFT calculations.