Huanling Liu , Yan Wang , Songsong Liu , Lili Lin , Yuzhi Song , Chuan-Kui Wang , Zhen Xie , Jianzhong Fan
{"title":"通过氧化和n-π*跃迁调制激子转移途径,实现高效的室温磷光","authors":"Huanling Liu , Yan Wang , Songsong Liu , Lili Lin , Yuzhi Song , Chuan-Kui Wang , Zhen Xie , Jianzhong Fan","doi":"10.1016/j.saa.2025.126625","DOIUrl":null,"url":null,"abstract":"<div><div>Organic room-temperature phosphorescence (RTP) materials hold promising applications in the field of display technologies and information encryption. Achieving efficient RTP emission relies on precisely regulating excited-state properties and luminescence pathways. In this study, three experimentally reported donor-acceptor molecules are selected, and the effects of oxidation on their photophysical properties are systematically investigated by first-principles calculations. The results show that oxidation of the donor units effectively modulates intramolecular charge transfer characteristics and the excited state energy levels, thereby influencing the reverse intersystem crossing (RISC) and exciton transfer processes, related thermally activated delayed fluorescence (TADF) and RTP emission mechanisms are revealed. Among the studied molecules, the fully oxidized molecule DOPTZ-CO exhibits the most favorable RTP performance. Using DOPTZ as the oxidized donor, three molecules featuring pronounced n-π* transition characteristics are further designed, and a novel strategy is proposed to regulate emission pathways by incorporating non-bonding (n) orbitals. The introduction of n-π* transition is found to play a dual role: it enhances spin-orbit coupling (SOC) effect, facilitating radiative T<sub>1</sub>-S<sub>0</sub> transitions and it also increases the S<sub>1</sub>-T<sub>1</sub> energy gap (ΔE<sub>ST</sub>), thereby suppressing RISC process and favoring RTP-dominated emission. Thus, molecules with moderate ΔE<sub>ST</sub> values (approximately 0.4 eV) and strong n-π* character demonstrate efficient and controllable RTP behavior. Overall, this study underscores the critical role of excited-state modulation and orbital engineering in tuning emission pathways and provides a theoretical foundation for the rational design of high-performance organic RTP materials.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"343 ","pages":"Article 126625"},"PeriodicalIF":4.3000,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Modulating exciton transfer pathways via oxidation and n-π* transitions for efficient room-temperature phosphorescence\",\"authors\":\"Huanling Liu , Yan Wang , Songsong Liu , Lili Lin , Yuzhi Song , Chuan-Kui Wang , Zhen Xie , Jianzhong Fan\",\"doi\":\"10.1016/j.saa.2025.126625\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Organic room-temperature phosphorescence (RTP) materials hold promising applications in the field of display technologies and information encryption. Achieving efficient RTP emission relies on precisely regulating excited-state properties and luminescence pathways. In this study, three experimentally reported donor-acceptor molecules are selected, and the effects of oxidation on their photophysical properties are systematically investigated by first-principles calculations. The results show that oxidation of the donor units effectively modulates intramolecular charge transfer characteristics and the excited state energy levels, thereby influencing the reverse intersystem crossing (RISC) and exciton transfer processes, related thermally activated delayed fluorescence (TADF) and RTP emission mechanisms are revealed. Among the studied molecules, the fully oxidized molecule DOPTZ-CO exhibits the most favorable RTP performance. Using DOPTZ as the oxidized donor, three molecules featuring pronounced n-π* transition characteristics are further designed, and a novel strategy is proposed to regulate emission pathways by incorporating non-bonding (n) orbitals. The introduction of n-π* transition is found to play a dual role: it enhances spin-orbit coupling (SOC) effect, facilitating radiative T<sub>1</sub>-S<sub>0</sub> transitions and it also increases the S<sub>1</sub>-T<sub>1</sub> energy gap (ΔE<sub>ST</sub>), thereby suppressing RISC process and favoring RTP-dominated emission. Thus, molecules with moderate ΔE<sub>ST</sub> values (approximately 0.4 eV) and strong n-π* character demonstrate efficient and controllable RTP behavior. Overall, this study underscores the critical role of excited-state modulation and orbital engineering in tuning emission pathways and provides a theoretical foundation for the rational design of high-performance organic RTP materials.</div></div>\",\"PeriodicalId\":433,\"journal\":{\"name\":\"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy\",\"volume\":\"343 \",\"pages\":\"Article 126625\"},\"PeriodicalIF\":4.3000,\"publicationDate\":\"2025-06-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1386142525009321\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"SPECTROSCOPY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1386142525009321","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"SPECTROSCOPY","Score":null,"Total":0}
Modulating exciton transfer pathways via oxidation and n-π* transitions for efficient room-temperature phosphorescence
Organic room-temperature phosphorescence (RTP) materials hold promising applications in the field of display technologies and information encryption. Achieving efficient RTP emission relies on precisely regulating excited-state properties and luminescence pathways. In this study, three experimentally reported donor-acceptor molecules are selected, and the effects of oxidation on their photophysical properties are systematically investigated by first-principles calculations. The results show that oxidation of the donor units effectively modulates intramolecular charge transfer characteristics and the excited state energy levels, thereby influencing the reverse intersystem crossing (RISC) and exciton transfer processes, related thermally activated delayed fluorescence (TADF) and RTP emission mechanisms are revealed. Among the studied molecules, the fully oxidized molecule DOPTZ-CO exhibits the most favorable RTP performance. Using DOPTZ as the oxidized donor, three molecules featuring pronounced n-π* transition characteristics are further designed, and a novel strategy is proposed to regulate emission pathways by incorporating non-bonding (n) orbitals. The introduction of n-π* transition is found to play a dual role: it enhances spin-orbit coupling (SOC) effect, facilitating radiative T1-S0 transitions and it also increases the S1-T1 energy gap (ΔEST), thereby suppressing RISC process and favoring RTP-dominated emission. Thus, molecules with moderate ΔEST values (approximately 0.4 eV) and strong n-π* character demonstrate efficient and controllable RTP behavior. Overall, this study underscores the critical role of excited-state modulation and orbital engineering in tuning emission pathways and provides a theoretical foundation for the rational design of high-performance organic RTP materials.
期刊介绍:
Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy (SAA) is an interdisciplinary journal which spans from basic to applied aspects of optical spectroscopy in chemistry, medicine, biology, and materials science.
The journal publishes original scientific papers that feature high-quality spectroscopic data and analysis. From the broad range of optical spectroscopies, the emphasis is on electronic, vibrational or rotational spectra of molecules, rather than on spectroscopy based on magnetic moments.
Criteria for publication in SAA are novelty, uniqueness, and outstanding quality. Routine applications of spectroscopic techniques and computational methods are not appropriate.
Topics of particular interest of Spectrochimica Acta Part A include, but are not limited to:
Spectroscopy and dynamics of bioanalytical, biomedical, environmental, and atmospheric sciences,
Novel experimental techniques or instrumentation for molecular spectroscopy,
Novel theoretical and computational methods,
Novel applications in photochemistry and photobiology,
Novel interpretational approaches as well as advances in data analysis based on electronic or vibrational spectroscopy.