Institute of New Drug Development, China Medical University, No.91 Hsueh-Shih Road, Taichung, 40402, Taiwan.
Department of Electrophysics, National Chiao Tung University, 1001 University Road, Hsinchu, 30010, Taiwan.
Sci Rep. 2019 Sep 4;9(1):12762. doi: 10.1038/s41598-019-49303-w.
In this report, the substitution of the oxygen group (=O) of Tetraphenylcyclopentadienone with =CR group (R = methyl ester or nitrile) was found to have tuned the electro-optical properties of the molecule. Although both groups are electrons withdrawing in nature, their absorption from UV-vis spectra analysis was observed to have been blue-shifted by methyl ester substitution and red-shifted by nitrile substitution. Interestingly, these substitutions helped to enhance the overall intensity of emission, especially in the context of methyl ester substitution whereby the emission was significantly boosted at higher concentrations due to hypothesized restrictions of intramolecular motions. These observations were explained through detailed descriptions of the electron withdrawing capability and steric properties of the substituents on the basis of density functional theory calculations.
在本报告中，我们发现将四苯环戊二烯酮中的氧基团（=O）替换为=CR 基团（R=甲酯或腈基）可以调节分子的光电性质。尽管这两个基团在本质上都是吸电子基团，但从紫外可见光谱分析中观察到，甲酯取代使吸收峰蓝移，腈基取代使吸收峰红移。有趣的是，这些取代有助于增强发射的整体强度，特别是在甲酯取代的情况下，由于假设的分子内运动限制，较高浓度下的发射显著增强。这些观察结果通过基于密度泛函理论计算的取代基的电子吸能力和空间性质的详细描述来解释。
