Time-Dependent Density-Functional Theory Investigation of the Fluorescence Behavior as a Function of Alkyl Chain Size for the 4-(N,N-Dimethylamino)benzonitrile-like Donor−Acceptor Systems 4-(N,N-Diethylamino)benzonitrile and 4-(N,N-Diisopropylamino)benzonitrile
Time-Dependent Density-Functional Theory Investigation of the Fluorescence Behavior as a Function of Alkyl Chain Size for the 4-(N,N-Dimethylamino)benzonitrile-like Donor−Acceptor Systems 4-(N,N-Diethylamino)benzonitrile and 4-(N,N-Diisopropylamino)benzonitrile
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DOI：
10.1021/jp0307699
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发表时间：
2004-05
影响因子：
3.3
通讯作者：
C. Jamorski;M. E. Casida
中科院分区：
文献类型：
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作者：
C. Jamorski;M. E. Casida
实验观察到，与4-（N，N-二甲氨基）苯腈（4DMAB - CN）相同家族的供体-受体系统随着其烷基链长度的增加，双荧光活性增加。在本研究中，利用时间依赖密度泛函理论（TDDFT）研究了4-（N，N-二乙基氨基）苯腈（4DEAB−CN）和4-（N，N-二异丙基氨基）苯腈（4DIAB−CN）分子的双荧光活性。利用MPW1PW91和Becke三参数Lee - Yang - Parr （B3LYP）混合泛函结合6-311+G（2d,p）基集计算了吸收和发射能量。在6-31G(d)基组下，对B3LYP水平的基态几何结构进行了优化。从扭曲分子内电荷转移（TICT）和平面分子内电荷转移（PICT）模型的角度研究了电荷转移激发态的形成，这些模型先前在文献中提出，用于解释双荧光行为。
It has been observed experimentally that donor−acceptor systems of the same familly as 4-(N,N-dimethylamino)benzonitrile (4DMAB−CN) exhibit increased dual fluorescence activity as their alkyl chain length becomes longer. In the present study, the dual fluorescence activity of 4-(N,N-diethylamino)benzonitrile (4DEAB−CN) and 4-(N,N-diisopropylamino)benzonitrile (4DIAB−CN) molecules is investigated using time-dependent density-functional theory (TDDFT). Absorption and emission energies have been computed with the MPW1PW91 and the Becke three-parameter Lee−Yang−Parr (B3LYP) hybrid functionals in combination with the 6-311+G(2d,p) basis set. The ground-state geometry has been optimized at the B3LYP level with the 6-31G(d) basis set. The formation of the charge-transfer excited state has been examined from the point of view of the twisting intramolecular charge-transfer (TICT) and planar intramolecular charge-transfer (PICT) models previously proposed in the literature to explain the dual fluorescence behavior ...