We designed and prepared a series of methyl benzoylformate (MBF) derivatives Norrish type I photoinitiators (MBFs) for light-emitting diode (LED)-induced photopolymerization through computer simulation. The potential photolysis mechanism of MBFs under LED at 405 nm was explored by steady-state photolysis, nuclear magnetic resonance, and electron spin resonance. The as-synthesized photoinitiator dimethyl 1,4-dibenzoylformate (DM-BD-F) can efficiently initiate free radical photopolymerization of acrylate monomers under LED irradiation at 405 nm. Moreover, we predicted well the photoinitiating capability of MBFs through the cleavage exothermy (ΔH) calculated by triplet bond dissociation energy (BDE) and triplet energy (E_T). Significantly, based on the weak absorption of MBFs at 405 nm, MBFs were successfully applied to deep-layer photocuring and the curing depth reached 6.5 cm after the irradiation of LED at 405 nm for 30 s. This research provides a new idea and efficient strategy for the molecular design of photoinitiators for deep-layer photocuring.

中文翻译：

---

苯甲酰甲酸甲酯衍生物Norrish I型光引发剂，用于在近紫外线或可见光下进行深层光固化

我们设计并制备了一系列甲基苯甲酰基甲酸酯（MBF）衍生物Norrish I型光引发剂（MBF），用于通过计算机仿真来诱导发光二极管（LED）引发的光致聚合。通过稳态光解，核磁共振和电子自旋共振探索了405 nm LED下MBF的潜在光解机理。合成后的光引发剂1,4-二苯甲酰基甲酸二甲酯（DM-BD-F）可以在405 nm的LED辐射下有效引发丙烯酸酯单体的自由基光聚合。此外，我们通过三重键解离能（BDE）和三重态能量（E _T）计算的裂解放热（ΔH）很好地预测了MBF的光引发能力。）。值得注意的是，由于MBF在405 nm处的吸收较弱，因此成功地将MBF应用于深层光固化，并且在405 nm下照射30 s后，固化深度达到6.5 cm。该研究为用于深层光固化的光引发剂的分子设计提供了新的思路和有效的策略。