Two-Way Molecular Switches with Large Nonlinear Optical Contrast
Two-Way Molecular Switches with Large Nonlinear Optical Contrast
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DOI：
10.1002/chem.200801967
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Champagne, Benoit
中科院分区：
文献类型：
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作者：
Mancois, Fabien;Pozzo, Jean-Luc;Champagne, Benoit
为了优化非线性光学（NLO）对比度，合成了一系列在吲哚基对位上引入吸电子取代基的吲哚恶唑烷衍生物。它们的线性和非线性光学性质的特征在于紫外-可见吸收和超瑞利散射测量，以及从头计算。双向光或pH触发开关机制已被证明通过比较的两性离子和质子化的开放形式（POF）的吸收光谱。超瑞利测量已经揭示了封闭的吲哚啉基恶唑烷和开放的π-共轭有色形式之间的二阶NLO对比度在取代后保持非常大。理论和测量结果表明，对于POFs的第一超极化率的幅度遵循的Hammett参数的吸光基团。然而，由于测量是在共振中进行的，为了恢复这种行为，需要精心设计的程序，包括均匀和不均匀的加宽，以及单模振动结构，以外推到静态极限。
To optimize the nonlinear optical (NLO) contrast, a series of indolinooxazolidine derivatives with electron-withdrawing substituents in the para position on the indolinic residue have been synthesized. Their linear and nonlinear optical properties have been characterized by UV-visible absorption and hyper-Rayleigh scattering measurements, as well as by ab initio calculations. The two-way photo- or pH-triggered switching mechanism has been demonstrated by comparing the absorption spectra of the zwitterionic and protonated open forms (POF). Hyper-Rayleigh measurements have revealed that the second-order NLO contrast between the closed indolinooxazolidine and the open pi-conjugated colored forms remain very large upon Substitution. Theory and measurements show that for the POFs the amplitude of the first hyperpolarizability follows the Hammett parameters of the withdrawing groups. However, because the measurements are performed in resonance, to recover this behavior, elaborate procedures including homogeneous and inhomogeneous broadenings, as well as single-mode vibronic structures are necessary to extrapolate to the static limit.