We present a group of seven new advanced symmetric iodonium salts bearing two benzylidene-based chromophores. This is the first example of the use of a double bond in the structure of a symmetric iodonium salt. Such an improvement ensures excellent absorbing properties in the UV-A and visible range, representing a significant advance over the commonly used diaryliodonium salts. New symmetric iodonium derivatives effectively photoinitiate cationic polymerization using light-emitting diodes (LEDs) with no additives. Thus, they can act as one-component photoinitiators even in visible light, where common diaryliodonium salts remain inactive. They can be used in advanced applications such as three-dimensional (3D) VAT printing using an LCD printer. In addition, it was possible to study in detail substituent effects on the properties of the new iodonium salts due to the easily modifiable structure of the benzylidene chromophore. The research described represents a significant advance in the development of iodonium salts.

中文翻译：

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基于亚苄基的对称碘盐作为单组分光引发剂在 3D 打印中的应用

我们展示了一组带有两个亚苄基发色团的七种新型高级对称碘鎓盐。这是在对称碘盐结构中使用双键的第一个例子。这种改进确保了在 UV-A 和可见光范围内具有出色的吸收性能，与常用的二芳基碘盐相比具有显着进步。新的对称碘衍生物使用发光二极管 (LED) 有效地光引发阳离子聚合，无需添加剂。因此，即使在可见光下，它们也可以作为单组分光引发剂，而普通的二芳基碘盐在可见光下仍保持无活性。它们可用于高级应用，例如使用 LCD 打印机进行三维 (3D) 增值税打印。此外，由于亚苄基发色团的结构易于修改，因此可以详细研究取代基对新碘鎓盐性质的影响。所描述的研究代表了碘盐开发的重大进展。