Non-adiabatic conformation distortion charge transfer enables dual emission of thermally activated delayed fluorescence and room temperature phosphorescence

Yurong Guo; Hongwei Guan; Peng Li; Chao Wang; Yanan Wang; Jingran Zhang; Guangjiu Zhao

doi:10.1016/j.saa.2024.124032

Non-adiabatic conformation distortion charge transfer enables dual emission of thermally activated delayed fluorescence and room temperature phosphorescence

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Apr 15:311:124032. doi: 10.1016/j.saa.2024.124032. Epub 2024 Feb 12.

Authors

Yurong Guo¹, Hongwei Guan², Peng Li², Chao Wang³, Yanan Wang⁴, Jingran Zhang⁴, Guangjiu Zhao⁵

Affiliations

¹ School of Chemical and Biological Engineering, Qilu Institute of Technology, Jinan 250200, China.
² Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266237, China.
³ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China; National Engineering Research Center of Biomaterials, Nanjing Forestry University, Nanjing 210037, China.
⁴ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China.
⁵ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China. Electronic address: gjzhao@tju.edu.cn.

PMID: 38364513
DOI: 10.1016/j.saa.2024.124032

Abstract

In this work, we report for the first time that thiophenol-substituted naphthalimide can achieve thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) simultaneously through non-conjugated flexible connection. Herein, we explain that the enhancement of intersystem crossing (ISC) between the singlet excited state and triplet excited states in NISPh is mainly caused by the non-adiabatic conformation distortion charge transfer (CDCT) of the excited states. More precisely, CDCT results in the conformation matching and energy barrier decrease between the excited states. In addition, the electronic and vibration coupling is further enhanced in NISPh. Our work substantiates a rational design strategy for the development of simple purely organic materials to achieve dual emission of TADF and RTP.

Keywords: Conformation distortion charge transfer; RTP; TADF; Thiophenol-substituted naphthalimide.