In this work, the in-silico rational design of new photoinitiators by molecular modeling for specific wavelength (here 405 nm) and specific applications (3D printing, composites) is reported. A large number of (keto)coumarin derivatives were investigated by molecular modeling and their synthesis and more detailed photochemical investigations are based on obtaining structures having both excellent predicted light absorption properties @405 nm and high excited state energy levels (to ensure high photochemical reactivity). More particularly, four new families of coumarins were designed (4 of the 19 proposed coumarins were never synthesized (N2,M6,T1,T6)): the first family is based on Nitrocoumarins (N1-N6), the second one on Methoxybenzene-based coumarins and Ethoxycoumarins (M1-M6), the third one on Thiophene-based coumarins (T1-T6) and the last family studied concerns Alkyne-based coumarin (A1). The purpose of this work concerns the study of the photoinitiating ability of these compounds in different monomers for different polymerization processes (free radical, cationic) using FTIR technique. The different compounds reported in this work are very efficient to initiate the free radical polymerization of (meth)acrylates but also the cationic polymerization of epoxides upon mild irradiation conditions using a Light Emitting Diode (LED) at 405 nm as visible light source. Nitrocoumarins were identified as the best candidates for photoinitiation among the different families of coumarins investigated in this work. More precisely, nitrocoumarins are characterized by very good polymerization profiles, great final reactive function conversions (FC) and also high rates of polymerization (Rp). The electrochemical and photochemical properties of the different compounds were also studied to get a deeper insight into the photochemical mechanisms supporting the initiation process. A full picture of the involved photochemical mechanisms is provided. Thanks to the astounding polymerization initiating ability of these coumarins, their use in 3D printing applications can be worthwhile. Remarkably, using these compounds, the preparation of photocomposites was possible even in difficult light penetration conditions resulting from the presence of fibers inside the resins.

在这项工作中，报告了通过针对特定波长（此处为405 nm）和特定应用（3D打印，复合材料）的分子建模对新型光引发剂进行硅内合理设计。通过分子建模及其合成方法对大量（酮）香豆素衍生物进行了研究，更详细的光化学研究是基于获得在405 nm处具有出色的预测光吸收特性和高激发态能级（以确保高光化学反应性）的结构为基础的。更具体地说，设计了四个新的香豆素家族（19种建议的香豆素从未合成（N2，M6，T1，T6））：第一个家族基于硝基香豆素（N1-N6）），第二个是基于甲氧基苯的香豆素和乙氧基香豆素（M1-M6），第三个是基于噻吩基的香豆素（T1-T6），最后一个家族研究的是基于炔基的香豆素（A1））。这项工作的目的涉及使用FTIR技术研究这些化合物在不同单体中对不同聚合过程（自由基，阳离子）的光引发能力。在这项工作中报道的不同化合物非常有效地引发了（甲基）丙烯酸酯的自由基聚合反应，而且在使用405 nm的发光二极管（LED）作为可见光源的温和辐射条件下，环氧化物的阳离子聚合反应非常有效。硝基香豆素被确定为这项研究中所研究的香豆素不同家族中光引发的最佳候选者。更精确地，硝基香豆素的特征在于非常好的聚合曲线，很大的最终反应功能转化率（FC）和很高的聚合速率（Rp）。还研究了不同化合物的电化学和光化学性质，以更深入地了解支持引发过程的光化学机理。提供了所涉及的光化学机理的全貌。由于这些香豆素具有惊人的聚合引发能力，因此在3D打印应用中使用它们是值得的。显着地，使用这些化合物，即使在由于树脂内部存在纤维而导致的困难的光穿透条件下，也可以制备光复合材料。它们在3D打印应用程序中的使用可能是值得的。显着地，使用这些化合物，即使在由于树脂内部存在纤维而导致的困难的光穿透条件下，也可以制备光复合材料。它们在3D打印应用程序中的使用可能是值得的。显着地，使用这些化合物，即使在由于树脂内部存在纤维而导致的困难的光穿透条件下，也可以制备光复合材料。