Redox and Photoisomerization Switching the Second-Order Nonlinear Optical Properties of a Tetrathiafulvalene Derivative Across Six States: A DFT Study
Redox and Photoisomerization Switching the Second-Order Nonlinear Optical Properties of a Tetrathiafulvalene Derivative Across Six States: A DFT Study
复制标题
氧化还原和光异构化在六种状态下切换四硫富瓦烯衍生物的二阶非线性光学性质：DFT 研究
DOI：
10.1021/jp2049958
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发表时间：
2011-12-08
影响因子：
3.7
通讯作者：
Muhammad, Shabbir
中科院分区：
文献类型：
--
作者：
Liu, Chun-Guang;Su, Zhong-Min;Muhammad, Shabbir
利用密度泛函理论（DFT）研究了四硫富瓦烯（TTF）衍生物的六个稳定态之间的二阶非线性光学（NLO）性质的转变.氧化还原活性TTF单元和光异构化发色团1，2-二噻吩基全氟环戊烯（DTE）已被实施切换的二阶非线性光学响应。我们的DFT计算与三个功能表明，引入的DTE部分的π共轭桥可以显着提高二阶非线性光学响应相关的供体/受体端在这项工作中。我们的密度泛函理论计算表明，光异构化引起了一系列化合物的几何结构的变化。相对于开环形式，闭环形式具有良好的π共轭，因此具有较大的二阶非线性光学响应。电子结构分析表明，TTF单元在单电子和双电子氧化过程中起氧化中心的作用。单电子和双电子氧化物的TTF单元平面结构比其中性化合物的TTF单元平面结构好，导致其激发能低，静态第一超极化率高。我们目前使用三个泛函的DFT计算表明，TTF衍生物4可以在六个稳定状态之间切换二阶NLO性质，这在之前报道的二阶NLO开关中是罕见的例子。
The switching of second-order nonlinear optical (NLO) properties for a tetrathiafulvalene (TTF) derivative across the six stable states has been studied by using the density Emotional theory (DFT) calculations. The redox-active TTF unit and a photoisomerized chromophore 1,2-dithienylperfluorocyclopentene (DTE) have been implemented to switch the second-order NLO responses. Our DFT calculations with three functionals demonstrate that introduction of the DTE moiety into the pi-conjugated bridge can significantly enhance the second-order NLO response relevant to the donor/acceptor end in this work. Our DFT calculations illustrate that photoisomerization bring forth a large change in the geometry of the series of compounds. The closed-ring form possesses a good pi-conjugation relative to the open-ring form and thus a large second-order NLO response. The electronic structure analysis shows that the TTF unit will perform as an oxidation center in the one- and two-electron-oxidation processes. The one- and two-electron-oxidized species have better planar structures of TTF unit than its neutral compound, which ultimately leads to the low excited energy and enhances the static first hyperpolarizability. Our present DFT calculations using three functionals show that the TTF derivative 4 can switch the second-order NLO properties across six stable states, which is a rare example in previously reported second-order NLO switches.