Photophysical Properties of Silyl-Substituted Stilbene Derivatives
Photophysical Properties of Silyl-Substituted Stilbene Derivatives
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DOI：
10.1002/ejoc.202000397
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发表时间：
2020-06-04
影响因子：
2.8
通讯作者：
Segi, Masahito
中科院分区：
文献类型：
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作者：
Maeda, Hajime;Horikoshi, Ryo;Segi, Masahito
研究了硅基对二苯乙烯的结构、吸收、荧光和光异构化性能的影响。与母体二苯乙烯(1)相比，me3si取代的二苯乙烯2-4和6在溶液中的荧光量子产率（phi(f)）更高。衍生物5，其中Me3Si基团存在于芳烃基团的所有邻位，在室温下没有荧光。与Me3Si类似物2相比，me3sime2si取代二苯乙烯7的吸收和荧光波长最大值发生在更长的波长上。理论计算结果表明，这种差异是由于π -体系与sigma（Si-Si）轨道相互作用导致7的HOMO能量增加的结果。二苯乙烯14在两个对位上都有两个Me3Si-C相当于C的基团，具有很高的phi(f)（0.95）。计算的跃迁偶极矩（mu）与phi(f)具有良好的相关性。衍生物21含有相当于C基团的Ph2N和Me3SiC，由于其具有Ph2N基团与芳环正交的扭曲分子内电荷转移（TICT）激发态，表现出溶剂荧光性。
The effects of silyl groups on the structural, absorption, fluorescence, and photoisomerization properties of stilbenes were investigated. In comparison to that of the parent stilbene (1), fluorescence quantum yields (phi(f)) of Me3Si-substituted stilbenes 2-4 and 6 in solution were higher. Derivative 5, in which Me3Si groups are present at all ortho positions of the arene moieties, did not fluoresce at room temperature. The absorption and fluorescence wavelength maxima of Me3SiMe2Si-substituted stilbene 7 occurred at longer wavelengths compared to those of the Me3Si analog 2. The results of theoretical calculations showed that this difference is a consequence of an increase in the HOMO energy of 7 caused by orbital interaction between pi-system and the sigma(Si-Si) orbital. Stilbene 14, with two Me3Si-C equivalent to C groups at both para positions, had a high phi(f) (0.95). The calculated transition dipole moment (mu) was well correlated with phi(f). Derivative 21, which contains Ph2N and Me3SiC equivalent to C groups exhibited solvatofluorochromism because it possesses a twisted intramolecular charge transfer (TICT) excited state in which the Ph2N group and the aromatic ring are orthogonal.