Redox Properties of N,N′-Disubstituted Dihydrophenazine and Dihydrodibenzo[a,c]phenazine: The First Isolation of Their Crystalline Radical Cations and Dications

作者：Huang, Bin; Kang, Hao; Zhao, Xiao-Li; Yang, Hai-Bo; Shi, Xueliang^*

来源：Crystal Growth and Design, 2022, 22(6): 3587-3593.

DOI：10.1021/acs.cgd.2c00259

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• DESIGN

In this study, the redox behaviors of N,N'-disubstituted dihydrophenazine and dihydrodibenzo[a,c]phenazine and the distinct properties of their corresponding radical cation and dication species were systematically investigated and compared. A structure-activity relationship investigation revealed that the dication of dihydrophenazine was very reactive and unstable. Nevertheless, the unprecedented crystallization and single-crystal structures of their radical cation and dication species, especially the dication of dihydrophenazine DPPZ-B2+, were successfully achieved. X-ray crystallographic analysis unveiled the unique changes in the molecular geometry and electronic structure of dihydrophenazine and dihydrodibenzo[a,c]phenazine before and after oxidation. Moreover, the geometry planarization in the dihydrodibenzo[a,c]phenazine radical cation (DPAC(center dot+)) and dication (DPAC(2+)) was demonstrated for the first time, which could contribute to the understanding of its intriguing conformation-adaptive behavior. We expect that this study will provide new insight into the understanding of the structure-activity and structure-conformation relationship of dihydrophenazines, which can be helpful to the design and application of dihydrophenazine-based materials in the future.