The role played by ethanol in achieving the successive versus simultaneous mechanism of excited-state double proton transfer in dipyrido[2,3-a:3′,2′-i]carbazole
The role played by ethanol in achieving the successive versus simultaneous mechanism of excited-state double proton transfer in dipyrido[2,3-a:3′,2′-i]carbazole
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乙醇在实现联吡啶并[2,3-a:3-,2-i]咔唑激发态双质子转移的连续与同时机制中所起的作用
DOI：
10.1039/c8cp05716h
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发表时间：
2018
影响因子：
3.3
通讯作者：
Shi Ying
中科院分区：
文献类型：
--
作者：
Han Jianhui;Liu Xiaochun;Li Hui;Yin Hang;Zhao Huifang;Ma Lina;Song Yaodong;Shi Ying
采用密度泛函理论（DFT）和含时密度泛函理论（TDDFT）研究了双吡啶并[2，3-a：3′，2 ′-i]咔唑（DPC）在乙醇（EtOH）溶剂中的激发态双质子转移（ESDPT）过程.计算结果提供了令人信服的证据，质子转移没有发生自发的DPC单体，由于缺乏氢键。有趣的是，加入乙醇后，DPC，两个分子间氢键在基态形成，和分子间氢键的激发态得到加强，通过比较的主要键参数的变化证实。此外，与DPC单体相比，在DPC-EtOH复合物中观察到电荷转移。特别是，一个可靠的ESDPT过程发生在系统内的光激发，这是监测的形成和消失的特征峰在IR光谱。实验结果充分证明了乙醇的参与对ESDPT过程有显著的影响。总体而言，我们的工作不仅全面阐述了ESDPT的同步机制，而且还为新分子的设计和合成铺平了道路。
The excited-state double proton transfer (ESDPT) process of dipyrido[2,3-a:3′,2′-i]carbazole (DPC) in ethanol (EtOH) solvent is investigated using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The computational results provide convincing evidence that proton transfer did not occur spontaneously for the DPC monomer due to the lack of hydrogen bonds. Interestingly, after adding EtOH to DPC, two intermolecular hydrogen bonds were formed in the ground-state, and the intermolecular hydrogen bonds were strengthened in the excited-state, as confirmed by comparing the changes in the primary bond parameters. In addition, the charge transfer was observed in the DPC–EtOH complex compared with the DPC monomer. In particular, a reliable ESDPT process occurs within the system upon photoexcitation, which was monitored by the formation and disappearance of characteristic peaks in the IR spectrum. All results adequately proved that the participation of EtOH exerts a remarkable effect on the ESDPT process. Overall, our work not only comprehensively elaborated the simultaneous mechanism of ESDPT but can also pave the way towards the design and synthesis of novel molecules.