Aggregation induced blue-shifted emission--the molecular picture from a QM/MM study.
Aggregation induced blue-shifted emission--the molecular picture from a QM/MM study.
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DOI：
10.1039/c3cp54910k
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Qunyan Wu;Tian Zhang;Qian Peng;Dong Wang;Z. Shuai
中科院分区：
文献类型：
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作者：
Qunyan Wu;Tian Zhang;Qian Peng;Dong Wang;Z. Shuai
通常，固态中的光发射相对于溶液相是红移的。最近合成的一系列化合物表现出聚集诱导蓝移发射（AIBSE）现象。采用极化连续介质模型（PCM）和混合量子力学/分子力学（QM/MM）方法，在含时密度泛函理论（TD-DFT）水平上研究了几种典型AIE活性分子在溶剂和聚集体中的激发态电子结构.据发现，AIBSE现象起源于较小的重组能量在聚集体比在溶液相，证明通过限制的结构松弛，平面化的激发态，和冻结的低频面外扭曲的过渡态。
In general, optical emission in the solid-state is red-shifted with respect to the solution phase. A series of recently synthesized compounds exhibits aggregation induced blue-shifted emission (AIBSE) phenomena. By employing a polarizable continuum model (PCM) and a hybrid quantum mechanics/molecular mechanics (QM/MM) approach, we investigate the excited-state electronic structures of some typical AIE-active molecules both in solvents and in aggregates at the time-dependent density functional theory (TD-DFT) level. It is found that the AIBSE phenomena originate from the smaller reorganization energy in aggregates than in the solution phase, as evidenced through the restricted structural relaxation, planarization in the excited state, and freezing of low-frequency out-of-plane twists in the transition state.