Direct demonstration of triplet excimer in purely organic room temperature phosphorescence through rational molecular design

Zhenjiang Liu; Yu Tian; Jie Yang; Aisen Li; Yunsheng Wang; Jia Ren; Manman Fang; Ben Zhong Tang; Zhen Li

doi:10.1038/s41377-022-00826-4

Direct demonstration of triplet excimer in purely organic room temperature phosphorescence through rational molecular design

Light Sci Appl. 2022 May 17;11(1):142. doi: 10.1038/s41377-022-00826-4.

Authors

Zhenjiang Liu¹, Yu Tian¹, Jie Yang², Aisen Li³, Yunsheng Wang¹, Jia Ren¹, Manman Fang¹, Ben Zhong Tang^{4

5}, Zhen Li^{6

7

8

9

10}

Affiliations

¹ Institute of Molecular Aggregation Science, Tianjin University, Tianjin, 300072, China.
² Institute of Molecular Aggregation Science, Tianjin University, Tianjin, 300072, China. [email protected].
³ Joint School of National University of Singapore, Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.
⁴ Institute of Molecular Aggregation Science, Tianjin University, Tianjin, 300072, China. [email protected].
⁵ Shenzhen Institute of Molecular Aggregate Science and Engineering, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China. [email protected].
⁶ Institute of Molecular Aggregation Science, Tianjin University, Tianjin, 300072, China. [email protected].
⁷ Joint School of National University of Singapore, Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China. [email protected].
⁸ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, Tianjin, 300072, China. [email protected].
⁹ Department of Chemistry, Wuhan University, Wuhan, 430072, China. [email protected].
¹⁰ Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China. [email protected].

Abstract

Organic luminogens with room temperature phosphorescence (RTP) have been paid great attention and developed rapidly for their wide application values. Until now, the internal mechanism and source of phosphorescence are still obscure, especially for the relationship between molecular dimer and RTP emission. Hence, we designed and synthesized eight phenothiazine 5,5-dioxide derivatives to directly reveal how the monomer and dimer in packing affect the RTP behavior. Dimers with strong π-π stacking (θ < 20.66°; d < 3.86 Å) lead to pure triplet excimer emission, while those with weak π-π stacking (27.02°< θ < 40.64°; 3.84 Å < d < 4.41 Å) contribute to dual RTP emissions of both monomer and triplet excimer. The valuable information of this work would promote the further development of this research field, as well as others in aggregate.