文献类型：期刊文献

英文题名：Rational understanding of solvent effects on 4CzPN thermally activated delayed fluorescence emitter

作者：Yan, Shujie[1];Lu, Zhaoyue[1];Chen, Zhehao[1];Wang, Xiao[1];Xiao, Jing[2]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]Taishan Univ, Phys & Elect Engn Coll, Tai An 271021, Shandong, Peoples R China

年份：2025

卷号：280

外文期刊名：JOURNAL OF LUMINESCENCE

收录：;EI(收录号：20250517786455);WOS:【SCI-EXPANDED(收录号:WOS:001423752300001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (No. 62374112) and the Natural Science Founda-tion of Shandong Province, China (No. ZR2022MF271) .

语种：英文

外文关键词：Solvatochromism; Redshift; Stokes shift; Geometrical deformation; Reorganization energy

摘要：Carbazole dicyanobenzene derivatives are pioneering and representative thermally activated delayed fluorescence (TADF) molecules with high luminous efficiency. Comprehensive understanding of photophysical properties of TADF molecules in solution is instructive for extending their applications. In this work, the optical spectra, geometrical and electronic structures of 1,2,3,4-tetrakis(carbazol-9-yl)-5,6-dicyanobenzene (4CzPN) in cyclohexane, toluene, ethyl acetate, dichloromethane, dimethylformamide, and dimethyl sulfoxide solvents have been systematically investigated. Experimental spectra demonstrate that the redshift in the absorption peak is negligible whereas the emission peak exhibits a significant redshift upon increasing the solvent polarity. And the simulated spectral data using the M06-2X/6-31G* computational level combined with the polarizable continuum model solvent model are in great agreement with experimental observations. The linear relationship between the experimental emissive wavelength and dielectric constant underscores its potential for the polarity detection of environments. The simulated geometric and electronic structures of 4CzPN in various solutions illustrate that solvent polarity has a faint influence on the geometries and molecular orbitals but has a greater effect on the excited state energy. In addition, non-radiative decay process could be suppressed in polar solvent due to smaller geometrical change between the first singlet excited state and ground state, boosting the radiative decay rate. Our study provides an insight into the photophysical properties of 4CzPN in solution and we anticipate that it contributes to further understand the photophysical properties of TADF emitters in solution environments.