Quantum chemical insights into the aggregation induced emission phenomena: A QM/MM study for pyrazine derivatives
Quantum chemical insights into the aggregation induced emission phenomena: A QM/MM study for pyrazine derivatives
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DOI：
10.1002/jcc.23019
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发表时间：
2012-09
影响因子：
3
通讯作者：
Qunyan Wu;C. Deng;Qian Peng;Y. Niu;Z. Shuai
中科院分区：
文献类型：
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作者：
Qunyan Wu;C. Deng;Qian Peng;Y. Niu;Z. Shuai
与传统的聚集猝灭现象不同，近年来人们对聚集诱导发射（AIE）现象进行了深入的研究。采用量子力学和分子力学相结合的方法，研究了凝聚效应对吡嗪衍生物2，3-二氰基-5，6-二苯基吡嗪（DCDPP）和2，3-二氰基吡嗪并菲（DCPP）在凝聚相中激发态衰变的影响.结果表明，对于DCDPP，在所有温度下都存在AIE，这是因为苯环在气相中的扭转运动可以有效地耗散电子激发态能量，并在聚集体中受阻;而对于其“锁定”苯基对应物DCPP，理论计算只能给出正常的聚集猝灭。这些基于第一原理的发现与最近的实验一致。奇异AIE现象的主要起源是由于非辐射衰变效应。这是第一次基于聚集体的理论化学计算来理解AIE，这有助于解决目前对该机制的争议。© 2012 Wiley Periodicals，Inc.
There have been intensive studies on the newly discovered phenomena called aggregation induced emission (AIE), in contrast to the conventional aggregation quenching. Through combined quantum mechanics and molecular mechanics computations, we have investigated the aggregation effects on the excited state decays, both via radiative and nonradiative routes, for pyrazine derivatives 2,3‐dicyano‐5,6‐diphenylpyrazine (DCDPP) and 2,3‐dicyanopyrazino phenanthrene (DCPP) in condensed phase. We show that for DCDPP there appear AIE for all the temperature, because the phenyl ring torsional motions in gas phase can efficiently dissipate the electronic excited state energy, and get hindered in aggregate; while for its “locked”‐phenyl counterpart, DCPP, theoretical calculation can only give the normal aggregation quenching. These first‐principles based findings are consistent with recent experiment. The primary origin of the exotic AIE phenomena is due to the nonradiative decay effects. This is the first time that AIE is understood based on theoretical chemistry calculations for aggregates, which helps to resolve the present disputes over the mechanism. © 2012 Wiley Periodicals, Inc.