Recent advances on visible light Coumarin-based oxime esters as initiators of polymerization

4-Methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin

“…Coumarin, or 2H-chromen-2-one, is a natural bicyclic organic compound isolated from a variety of plants. Its derivatives have found broad applications such as fluorescent probes [1][2][3][4], food additives [5][6][7], in polymer chemistry [8][9][10][11], and so on. Numerous representatives have displayed variable bioactivity profiles [12][13][14][15][16][17][18], including anticancer [19][20][21][22][23][24], anti inflammatory [25][26][27], anti-tuberculosis [28,29], antimicrobial [30], and many others.…”

Coumarin Ketoxime Ester with Electron-Donating Substituents as Photoinitiators and Photosensitizers for Photopolymerization upon UV-Vis LED Irradiation

“…Thermal stability is a major issue in the development of oxime ester PIs because of the low bond energy of N-O, which is approximately 228 kJ/mol [ 43 ]. The thermodynamic stability and storage stability of COXEs in the formula were measured to evaluate their application potential.…”

“…Because of these excellent photophysical properties, coumarin has various applications in photopolymerization, such as for fluorescent molecular probes [ 37 ], functional monomers and polymers [ 38 , 39 ], sensitizers and initiators [ 40 , 41 , 42 ]. However, the reported coumarin-based sensitizers or oxime esters mostly focus on the 7-position substitute coumarin chromophores, such as 7-diethylaminocoumarin or 7-methoxycoumarin, which exhibit excellent photosensitive performance [ 20 , 31 , 43 ]. However, there are other substitution positions of the coumarin chromophore, such as the 6-position substitution (see Scheme 1 ), which also deserve a thorough investigation.…”

Recent advances on photobleachable visible light photoinitiators of polymerization

“…Coumarins have been extensively studied as visible light photoinitiators of polymerization due to their exceptional reactivity. [187][188][189][190][191][192] In light of this reactivity, various derivatives were designed and synthesized such as iodonium salts, [98] oxime esters, [193] water soluble structures, [194] or fused carbazole-coumarin hybrid structures. [190] Coumarins are versatile structures and more than 100 structures were reported in the literature, these structures being combined with different additives.…”