White Light Induced E/Z-Photoisomerization of Diphenylamine-Tethered Fluorescent Stilbene Derivatives: Synthesis, Photophysical, and Electrochemical Investigation
作者:Shachi Mishra、Pallavi Awasthi、Jagriti Singh、Rahul Kumar Gupta、Vikram Singh、Ruchir Kant、Ram Jeet、Debabrata Goswami、Atul Goel
DOI:10.1021/acs.joc.8b00033
日期:2018.4.6
A facile synthesis and detailed photophysical investigation of E/Z-isomerization of fluorescent diphenylamine tethered stilbene derivatives (DPASs) under white light exposure have been carried out to understand the effect on fluorescence, electrochemical properties, and photostability under various activation/deactivation pathways. In solution state, in the dark, the E-isomer of DPASs (6a–d) exhibited
荧光二苯胺拴二苯乙烯衍生物(DPASs)的E / Z异构化的简易合成和详细的光物理研究在白光照射下进行,以了解在各种活化/失活途径下对荧光,电化学性质和光稳定性的影响。在溶液状态下,在黑暗中,DPASs的E-异构体(6A - d)显示出高荧光量子产率(Φ FL ≈53%至60%的DMSO)。但是,在白光照射下,1 H NMR和HPLC研究表明DPAS 6a的纯E-异构体(〜9.5 mM)开始通过光异构化转变为Z形,直到达到接近平衡为止。在低浓度(约10μM)下,纯E异构体的吸收带在350–450 nm范围内逐渐减小,以采用Z构象6a'直至达到光平稳状态。通过X射线衍射分析明确地确认了E-异构体6a的结构。合成的DPAS化合物6a – d具有正溶剂溶变色性质,两个光子吸收性质和良好的热稳定性。使用DPAS的电化学研究表明可逆氧化导致形成稳定的自由基阳离子。由于有用的光物理,电化学和热性能,这