Designing thermally activated delayed fluorescence emitters with through-space charge transfer: a theoretical study

Jinhui Song; Xin Lv; Junjing Gu; ChiYung Yam; Lingyi Meng

doi:10.1039/d3cp05495k

Designing thermally activated delayed fluorescence emitters with through-space charge transfer: a theoretical study

Phys Chem Chem Phys. 2024 Feb 14;26(7):6420-6428. doi: 10.1039/d3cp05495k.

Authors

Jinhui Song^{1

2}, Xin Lv^{1

2}, Junjing Gu³, ChiYung Yam⁴, Lingyi Meng^{1

2

5}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China. lymeng@fjirsm.ac.cn.
² Fujian College, University of Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China.
³ State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
⁴ Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, 518000, China. yamcy@uestc.edu.cn.
⁵ Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen 361021, P. R. China.

PMID: 38317611
DOI: 10.1039/d3cp05495k

Abstract

Recently, thermally activated delayed fluorescence (TADF) molecules with through-space charge transfer (TSCT) features have been widely applied in developing organic light-emitting diodes with high luminescence efficiencies. The performance of TSCT-TADF molecules depends highly on their molecular structures. Therefore, theoretical investigation plays a significant role in designing novel highly efficient TSCT-TADF molecules. Herein, we theoretically investigate two recently reported TSCT-TADF molecules, 1'-(2,12-di-t-butyl[1,4]benzoxaborinino[2,3,4-kl]phenoxaborinin-7-yl)-10-phenyl-10H-spiro[acridine-9,9'-fluorene] (AC-BO) and 1-(2,12-di-t-butyl[1,4]benzoxaborinino[2,3,4-kl]phenoxaborinin-7-yl)-9',9'-dimethyl-9'H-spiro [fluorene-9,5'-quinolino[3,2,1-de]acridine](QAC-BO). The calculated photophysical properties (e.g. excited state energy levels and luminescence properties) for these two compounds are in good agreement with experimental data. Based on the systematic analysis of structure-performance relationships, we design three novel TSCT-TADF molecules with high molecular rigidity and evident TSCT features, i.e., DQAC-DBO, DQAC-SBO, and DQAC-NBO. They exhibit deep-blue light emissions and fast reverse intersystem crossing rates (K_RISCs). Our calculations demonstrate that the nearly coplanar orientation of the donor and acceptor is critical to achieve remarkable K_RISCs and fluorescence efficiencies in TSCT-TADF molecules.