Photoinitiators and photoinitiation Part 11. The photodecomposition of some O-acyl 2-oximinoketones

Groenenboom, C.J.; Hageman, Hendrik J.; Oosterhoff, Pieter; Overeem, Ton; Verbeek, Jan

doi:10.1016/s1010-6030(96)04617-5

Cited by 32 publications

(22 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been reported that oxime‐ester derivatives undergo photocleavage followed by decarboxylation in high quantum yields . The colour disappearance of the pH indicator confirmed the release of CO 2 when OEC3‐2 solution was irradiated (Figure S3).…”

Section: Methodsmentioning

confidence: 57%

Cleavable Unimolecular Photoinitiators Based on Oxime‐Ester Chemistry for Two‐Photon Three‐Dimensional Printing

Qiu

Zhu

et al. 2019

ChemPhotoChem

View full text Add to dashboard Cite

The development of efficient two-photon initiators (2PIs) is critical to promote two-photon three-dimensional (3D) printing for market applications. On the basis of the photocleavage concept, several unimolecular 2PIs that contain coumarin moieties (as two-photon absorption chromophores) and oximeester groups (as initiation functional groups) were synthesized. Under visible light irradiation, the investigated oxime-esters, sensitive to a broad wavelength range from 400 to 460 nm, undergo direct photocleavage followed by decarboxylation, forming active free radicals to effectively induce polymerization. Interestingly, the photoinitiators exhibit good photobleaching properties, which makes them applicable for photopolymerization of thick materials and dental restorative materials. In twophoton 3D printing tests with acrylate formulations, the oximeester derivatives were used to build complex 3D microstructures with submicrometer or even nanometer spatial resolution. The initiator comprised of a conjugated coumarin and an oxime ester attached at the 3-position exhibited a low threshold laser power required for polymerization and had a broad processing window similar to a highly efficient 2PI in the literature.

show abstract

Section: Methodsmentioning

confidence: 57%

Cleavable Unimolecular Photoinitiators Based on Oxime‐Ester Chemistry for Two‐Photon Three‐Dimensional Printing

Qiu

Zhu

et al. 2019

ChemPhotoChem

View full text Add to dashboard Cite

show abstract

“…As attractive Type I PIs, oxime esters (OXE's) have long been known for their high photoreactivity in the photopolymerization process. 12,[19][20][21][22][23][24] Their high efficiency is attributed to the cleavage of the N─O bond under light irradiation generating iminyl and acyloxy radicals, [21][22][23] which in turn can undergo further fragmentation by a decarboxylation reaction. 24 The usual cleavage in the OXE is mainly expected from the triplet state (T 1 ), but depending on the structure of the OXE, cleavage from the singlet state (S 1 ) has also been suspected (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

Novel phenylamine‐based oxime ester photoinitiators for LED‐induced free radical, cationic, and hybrid polymerization

Hammoud

Lee

Graff

et al. 2021

Journal of Polymer Science

View full text Add to dashboard Cite

Four new photoinitiators (PI's) containing various phenylamine-based groups as chromophores and oxime ester (OXE) as initiating groups are proposed for the free radical polymerization, the cationic polymerization, and interpenetrated polymer networks upon visible light exposure using a light emitting diodes at 405 nm. These compounds showed outstanding polymerization photoinitiation ability, that is, high-polymerization rates and good final reactive function conversions were obtained. The chemical mechanisms by which these OXE's generate reactive species were investigated through different techniques including real-time Fourier transform infrared spectroscopy, UVvisible spectroscopy, fluorescence (time-resolved or steady state) as well as cyclic voltammetry. Markedly, the proposed structures can be used as thermal initiators indicating all of them can be polymerized under suitable reaction temperature. In addition, due to their high efficiency, these optimized PI's were found to be useful @405 nm for both direct laser write and 3D printing applications.

show abstract

“…[101] Primary N-O bond cleavage into a-ketoiminyl and acyloxy radicals from the triplet excited state was observed in all cases. [101] Primary N-O bond cleavage into a-ketoiminyl and acyloxy radicals from the triplet excited state was observed in all cases.…”

mentioning

confidence: 88%

Photopolymerization: A Review

Kaur

Srivastava

2002

Journal of Macromolecular Science, Part C: Polymer Reviews

124

View full text Add to dashboard Cite

Photoinitiators and photoinitiation Part 11. The photodecomposition of some O-acyl 2-oximinoketones

Cited by 32 publications

References 38 publications

Cleavable Unimolecular Photoinitiators Based on Oxime‐Ester Chemistry for Two‐Photon Three‐Dimensional Printing

Cleavable Unimolecular Photoinitiators Based on Oxime‐Ester Chemistry for Two‐Photon Three‐Dimensional Printing

Novel phenylamine‐based oxime ester photoinitiators for LED‐induced free radical, cationic, and hybrid polymerization

Photopolymerization: A Review

Contact Info

Product

Resources

About