Photochemistry and photoinitiator properties of 2-substituted anthraquinones: 2. Photopolymerization and flash photolysis

Allen, Norman S.; Pullen, Graeme; Shah, Milla; Edge, Michèle; Weddell, Iain; Swart, Ron; Catalina, F.

doi:10.1016/0032-3861(95)96834-u

Cited by 22 publications

(9 citation statements)

References 5 publications

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“…Therefore, this makes it less photochemically reactive. This fact is also in agreement with much of our previous reported studies [1][2][3][4][5][6][7][8]. We found that many 2-substituted anthraquinones exhibited a longest wavelength absorption maximum at between 330-360nm with a small and variable shift.…”

Section: Spectroscopic Study On the 2 Substituted Methylanthraquinonessupporting

confidence: 93%

“…The photophysical and photochemical properties of anthraquinone derivatives has been one of the main areas of study in our research investigating the relationship and understanding between molecular structure, excited state properties and light stability and photochemical activity [1][2][3][4][5][6][7][8]. They have many applications in dye and pigmentbased, water and oil miscible, acrylated matrices.…”

Section: Introductionmentioning

confidence: 99%

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Photochemistry and photopolymerisation of substituted 2-methylanthraquinones and novel 2-acryloxymethylanthraquinone in radiation curing

Allen

Hamzah

Edge

et al. 2018

Journal of Photochemistry and Photobiology A: Chemistry

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Anthraquinones have been the subject of numerous photochemical studies and their photopolymerization activities have been examined under various conditions to improve more efficient photochemical systems. This article involves further detailed investigations into the photophysical, photochemistry and photopolymerisation properties of 4 commercial derivatives of 2-substituted anthraquinone, namely, 2-Bromomethylanthraquinone (2BA), 2 Chloromethylanthraquinone (2CA), 2 Ethylanthraquinone (2EA), 2 Hydroxymethylanthraquinone (2HA) and one novel synthesized anthraquinone, 2 Acryloxymethylanthraquinone (2AA). 2AA is synthesized from 2HA. The results from both spectroscopic and analysis studies proved the 2AA to having the ester link. Absorption spectroscopy and solvent shift data are used to characterise their spectral activity. Luminescence studies involving fluorescence and phosphorescence analysis indicates efficient intersystem crossing to triplet state and n-π* nature of the lowest excited triplet state. The polymerisation activity was studied using methyl methacrylate (MMA) and analysis of the cure rate was measured using the gravimetric method. All the compounds are shown to be highly dependent on the structure. However, the rate of polymerisation (Rp) was reduced in the presence of amine. This is consistent with other results, proving the behaviour of derivatives with n-π* configuration. Hardness tests for all compounds took place using a different formula of acrylated resin/monomer systems. The excited state characteristics of the methyl derivatives have also been examined using micro and nanosecond flash photolysis. Triplet absorption spectra of all the anthraquinone derivatives show a significant red shift in the region of 340-370nm with increasing solvent polarity due to stabilisation of the lowest triplet state by solvent reorganization. Hydrogen atom abstraction takes place in 2 propanol, forming a semiquinone radical. In the presence of the tertiary amine, triethylamine, all anthraquinone derivatives show the formation of intermediary species related to either the exciplex or the radical ion pair. Under aerobic conditions, the first decay rate for all anthraquinone derivatives increases and showed oxygen to be a good quencher with a bimolecular rate constant of around 2 x 10 8 mol.dm-3 s-1. Relative to benzophenone, the molar absorption coefficient, ε, and quantum yield of intersystem crossing, Φisc were calculated, and it is summarised that the value for Φisc for all compound is less than 1.00 and controls to a major extent their photochemical activities.

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Section: Spectroscopic Study On the 2 Substituted Methylanthraquinonessupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Photochemistry and photopolymerisation of substituted 2-methylanthraquinones and novel 2-acryloxymethylanthraquinone in radiation curing

Allen

Hamzah

Edge

et al. 2018

Journal of Photochemistry and Photobiology A: Chemistry

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“…[145][146][147][148][149], is mainly associated with radical photopolymerization reactions (only one paper [145] was concerned with CP) under UV light irradiation. Very recently, we discovered that one of the PISs based on a commercial anthraquinone derivative (oil blue N, OBN) is efficient for the CP of EPOX and DVE-3 and thiol-ene photopolymerization upon a red light irradiation (see Section 4.3.3.4) [150].…”

Section: Anthraquinone Derivativesmentioning

confidence: 99%

Visible light sensitive photoinitiating systems: Recent progress in cationic and radical photopolymerization reactions under soft conditions

Xiao

Zhang

Dumur

et al. 2015

Progress in Polymer Science

491

248

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“…Formation of initiating radicals in Type II photoinitiation occurs by absorption of light by a photoinitiator (ketone type photoinitiators, for example) which is followed by interaction with the co-initiator compounds resulting in radical generation. 35,36 Benzophenone, 37,38 thioxanthone, 39−41 ketocoumarin, 42 camphorquinone, 43−46 anthraquinone, 47,48 and their derivatives are examples of the most widely used Type II photoinitiators. The interaction of the excited photoinitiator with the co-initiator, depending on the nature of the co-initiator, may happen through different pathways, including hydrogen abstraction or electron transfer or an involvement of both electron transfer and hydrogen abstraction processes.…”

Section: Photoinitiation Of Chain Polymerization By Photoinduced Elec...mentioning

confidence: 99%

“…According to their optical behavior in the formation of initiating species, photoinitiators are generally subdivided into two general classes of Type I or those capable of forming initiating radicals directly upon bond cleavage on absorption of light and Type II which generate radicals in conjunction with various co-initiators. Formation of initiating radicals in Type II photoinitiation occurs by absorption of light by a photoinitiator (ketone type photoinitiators, for example) which is followed by interaction with the co-initiator compounds resulting in radical generation. , Benzophenone, , thioxanthone, − ketocoumarin, camphorquinone, − anthraquinone, , and their derivatives are examples of the most widely used Type II photoinitiators. The interaction of the excited photoinitiator with the co-initiator, depending on the nature of the co-initiator, may happen through different pathways, including hydrogen abstraction or electron transfer or an involvement of both electron transfer and hydrogen abstraction processes.…”

Section: Photoinitiation Of Chain Polymerization By Photoinduced Elec...mentioning

confidence: 99%

Photoinduced Electron Transfer Reactions for Macromolecular Syntheses

2016

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Photochemical reactions, particularly those involving photoinduced electron transfer processes, establish a substantial contribution to the modern synthetic chemistry, and the polymer community has been increasingly interested in exploiting and developing novel photochemical strategies. These reactions are efficiently utilized in almost every aspect of macromolecular architecture synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Merging with polymerization techniques, photochemistry has opened up new intriguing and powerful avenues for macromolecular synthesis. Construction of various polymers with incredibly complex structures and specific control over the chain topology, as well as providing the opportunity to manipulate the reaction course through spatiotemporal control, are one of the unique abilities of such photochemical reactions. This review paper provides a comprehensive account of the fundamentals and applications of photoinduced electron transfer reactions in polymer synthesis. Besides traditional photopolymerization methods, namely free radical and cationic polymerizations, step-growth polymerizations involving electron transfer processes are included. In addition, controlled radical polymerization and "Click Chemistry" methods have significantly evolved over the last few decades allowing access to narrow molecular weight distributions, efficient regulation of the molecular weight and the monomer sequence and incredibly complex architectures, and polymer modifications and surface patterning are covered. Potential applications including synthesis of block and graft copolymers, polymer-metal nanocomposites, various hybrid materials and bioconjugates, and sequence defined polymers through photoinduced electron transfer reactions are also investigated in detail.

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Photochemistry and photoinitiator properties of 2-substituted anthraquinones: 2. Photopolymerization and flash photolysis

Cited by 22 publications

References 5 publications

Photochemistry and photopolymerisation of substituted 2-methylanthraquinones and novel 2-acryloxymethylanthraquinone in radiation curing

Photochemistry and photopolymerisation of substituted 2-methylanthraquinones and novel 2-acryloxymethylanthraquinone in radiation curing

Visible light sensitive photoinitiating systems: Recent progress in cationic and radical photopolymerization reactions under soft conditions

Photoinduced Electron Transfer Reactions for Macromolecular Syntheses

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