基于基态和激发态之间跃迁过程的DBTTF-TCNB共晶的光热转换机制  

Photothermal conversion mechanism of the dibenzotetrathiafulvalene-tetracyanobenzene cocrystal based on the transitions between the ground and excited states

作　　者：付思姚 何旦 张小涛 Siyao Fu;Dan He;Xiaotao Zhang(Key Laboratory of Organic Integrated Circuits,Ministry of Education&Tianjin Key Laboratory of Molecular Optoelectronic Sciences,Department of Chemistry,School of Science,Tianjin University,Tianjin 300072,China;Key Laboratory of Organic Integrated Circuits,Ministry of Education&Tianjin Key Laboratory of Molecular Optoelectronic Sciences,Department of Chemistry,Institute of Molecular Aggregation Science,Tianjin University,Tianjin 300072,China;College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China)

机构地区：[1]Key Laboratory of Organic Integrated Circuits,Ministry of Education&Tianjin Key Laboratory of Molecular Optoelectronic Sciences,Department of Chemistry,School of Science,Tianjin University,Tianjin 300072,China [2]Key Laboratory of Organic Integrated Circuits,Ministry of Education&Tianjin Key Laboratory of Molecular Optoelectronic Sciences,Department of Chemistry,Institute of Molecular Aggregation Science,Tianjin University,Tianjin 300072,China [3]College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China

出　　处：《Science China Materials》2024年第1期242-250,共9页中国科学（材料科学）（英文版）

基　　金：supported by the Ministry of Science and Technology of China (2022YFA1204401);the National Natural Science Foundation of China (52121002 and U21A6002);Tianjin Natural Science Foundation (20JCJQJC00300)。

摘　　要：有机共晶,由于其光热转换性质,为光热成像、生物应用和海水淡化等诸多领域带来了希望和活力.然而,有机共晶的光热转换机制尤其缺少详细且深入的理论研究.本研究使用含时密度泛函理论方法探索了激发和去激发过程,并解释了DBTTF-TCNB共晶比其组分单晶具有更高光热转换效率的原因.结果显示,高激发态的高占比促进了非辐射跃迁的发生.基于DBTTF-TCNB共晶中给电子基团和吸电子基团间的电荷转移结果,我们发现给体和受体之间吸引电子的竞争可能会促进光热转换,且给电子基团在共晶结构中也十分重要.这些结果可为光热转换共晶的设计提供理论指导.轨道贡献和电子密度差进一步证明了我们的结论.因此,本研究从量子化学的角度给光热共晶在创新领域的应用提供了理论依据.Organic cocrystals have been bringing hope and vitality into several fields,such as photothermal imaging,biological application,and seawater desalination,owing to their photothermal conversion property.However,their mechanism of photothermal conversion is particularly lacking detailed and in-depth theoretical research.In this study,timedependent density functional theory was used to explore the excitation and deexcitation processes and explain the reason for the higher photothermal conversion efficiency of dibenzotetrathiafulvalene-tetracyanobenzene(DBTTF-TCNB)cocrystal than its component single crystals.The results reveal that the great proportion of high excited states promotes the occurrence of the nonradiative transition.Based on the result of the charge transfer between the electron-donating group and the electron-withdrawing group in the DBTTF-TCNB cocrystal,we found that the electron-withdrawing competition between the donor and acceptor might promote the photothermal conversion.Certainly,the electron-donating group in the cocrystal structure is also crucial.These results may offer some guidance for the design of photothermal conversion cocrystals.The orbital contribution and electron density difference further confirm our conclusion.Therefore,our research could provide the basis for applications of photothermal cocrystals in innovative fields from the perspective of quantum chemistry.

关 键 词：光热转换 含时密度泛函理论 激发过程 生物应用 吸电子基团 非辐射跃迁 高激发态 共晶结构 

分 类 号：O73[理学—晶体学]