Five visible-light-absorbing triphenylamine-based chalcone photoinitiators (CY1–CY5) that contain peripheral triphenylamines at both sides with various methoxy substituents of the triphenylamine moiety have been synthesized for application in free radical photopolymerization. They were confirmed through ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and Fourier-transform mass spectrometry results. All the compounds exhibited near-ultraviolet (UV) and visible-light absorption with a maximum absorption peak at approximately 426 nm. The photochemical reaction behavior of the compounds was investigated through photolysis, cyclic voltammetry, electron spin resonance, and theoretical calculations. Chalcone derivatives in combination with triethanolamine (TEOA) as a coinitiator were prepared and employed to initiate the free radical photopolymerization of trimethylolpropane triacrylate (TMPTA) by using a photo-DSC instrument. The CY1-based formulation exhibited the highest final conversion efficiency under UV lamp irradiation (43%), whereas the CY4-based formulation had the highest efficiency under 405 nm LED light irradiation (43%). In this study, the effects of the methoxy position and different-wavelength light sources were clearly investigated and discussed.

中文翻译：

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甲氧基取代基数目和位置对三苯胺基查尔酮可见光吸收光引发剂的影响

已经合成了五种基于可见光吸收的三苯胺基查尔酮光引发剂 ( CY1-CY5 )，它们在两侧均含有外围三苯胺，三苯胺部分具有各种甲氧基取代基，可用于自由基光聚合。它们通过¹ H 核磁共振 (NMR) 得到证实，¹³C NMR和傅里叶变换质谱结果。所有化合物均表现出近紫外 (UV) 和可见光吸收，最大吸收峰约为 426 nm。通过光解、循环伏安法、电子自旋共振和理论计算研究了化合物的光化学反应行为。制备了查尔酮衍生物与三乙醇胺 (TEOA) 作为共引发剂，并使用光 DSC 仪器引发三羟甲基丙烷三丙烯酸酯 (TMPTA) 的自由基光聚合。基于CY1的配方在紫外灯照射下表现出最高的最终转换效率 (43%)，而CY4基于 的配方在 405 nm LED 光照射下具有最高的效率 (43%)。在本研究中，对甲氧基位置和不同波长光源的影响进行了明确的研究和讨论。