Unraveling the Configuration Modulation in Spiro-based Through-Space Charge Transfer Materials

Yang-Kun Qu; Qi Zheng; Dong-Ying Zhou; Lin-Song Cui; Liang-Sheng Liao; Zuo-Quan Jiang

doi:10.1002/anie.202418008

Unraveling the Configuration Modulation in Spiro-based Through-Space Charge Transfer Materials

Angew Chem Int Ed Engl. 2024 Nov 24:e202418008. doi: 10.1002/anie.202418008. Online ahead of print.

Authors

Yang-Kun Qu¹, Qi Zheng², Dong-Ying Zhou², Lin-Song Cui³, Liang-Sheng Liao², Zuo-Quan Jiang⁴

Affiliations

¹ Soochow University, Institute of Functional Nano & Soft Materials (FUNSOM, Ren'ai road 199, Suzhou, 215000, Suzhou, CHINA.
² Soochow University, Institute of Functional Nano & Soft Materials (FUNSOM, Ren'ai road 199, 215000, Suzhou, CHINA.
³ USTC: University of Science and Technology of China, Department of chemistry, 230026, Hefei, CHINA.
⁴ Soochow University, Institute of Functional Nano & Soft Materials, 199 Ren-ai Road, 215123, Suzhou, CHINA.

PMID: 39582255
DOI: 10.1002/anie.202418008

Abstract

Thermally activated delayed fluorescence (TADF) materials hold promise for optoelectronic applications. Among various design strategies, through-space charge transfer (TSCT) systems offer the potential for enhanced performance. However, the relationship between molecular configuration and TSCT properties remains unclear compared to traditional through-band charge transfer materials. In this study, we investigated the influence of spatial configuration on TSCT features and electronic properties of triplet excited states in these TSCT materials. By manipulating the spatial arrangement between donor and acceptor segments using different spiro skeletons, a series of TSCT materials (DMB2-DMB5) was synthesized. Together with the parent molecule, DM-B, these materials exhibited completely different TADF characteristics, demonstrating the impact of spatial arrangements on their optoelectronic properties. Thus, the external quantum efficiency of these materials ranged from as high as 28.0% (DMB2) to as low as 3.6% (DMB5) due to variations in their TADF characteristics. Our findings highlight the significance of spatial configuration, beyond distance alone, in influencing TSCT properties when donor and acceptor segments are sufficiently close. This insight provides valuable guidance for developing advanced TSCT materials and advancing TADF systems with improved performance and functionality.

Keywords: Charge transfer excited states; Located excited states; Spiro materials; Thermally Activated Delayed Fluorescence; Through space charge transfer.