Triplet state of acetone in solution. Deactivation and hydrogen abstraction

Porter, George; Dogra, S. K.; Loutfy, Rafik O.; Sugamori, S. E.; Yip, R. W.

doi:10.1039/f19736901462

Cited by 111 publications

(46 citation statements)

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“…Some examples of addition of triplet acetone to unsaturated CvC bonds are known as well. 29 If this takes place in our system, it will not lead to rGO as the end product. Two other alternatives for triplet acetone would be one-electron oxidation of GO or energy transfer to GO, generating a radical-cation GO •+ or excited GO* species, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…The latter is known as an efficient H-abstractor from weak C-H bonds. 29 A great majority of hydrogen atoms in GO is present in the form of hydroxyl and carboxyl groups, i.e. they are hardly abstractable 45 and the contribution of this route can be neglected.…”

Section: Resultsmentioning

confidence: 99%

“…The lifetime of triplet acetone in aqueous 0.05 M acetone solution without any quencher is 50 ± 2 µs (7). 29 This value is shortening in the presence of the triplet acetone quenchers. The triplet acetone reacts with 2-PrOH via H-atom abstraction with a rate constant of 9.7 × 10 5 dm 3 mol −1 s −1 (8).…”

Section: Indirect Photoreduction Of Go With Acetone/2-prohmentioning

confidence: 99%

“…The (CH 3 ) 2 C • (OH) radicals can also be easily produced photochemically by UV-irradiation of the 2-PrOH/acetone system with a quantum yield of approximately unity (quantitative reaction). 29 Here, we demonstrate the highly efficient indirect UVinduced reduction of GO by (CH 3 ) 2 C • (OH) radicals generated from acetone/2-PrOH (see scheme in Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

“…The mechanism behind this accelerated reaction must be very different from the ones described before for solely added 2-PrOH and acetone, respectively, and it can be assumed that those reaction mechanisms contribute less than 7%, based on the data presented in Table 1 (calculated as 100% × 2 min/60 min multiplied by a factor of 2). Thus, the photochemistry of the acetone/2-PrOH couple must be considered 29 and it can be described by the reactions (7) and (8) via triplet acetone formation and reaction with 2-PrOH radicals. The lifetime of triplet acetone in aqueous 0.05 M acetone solution without any quencher is 50 ± 2 µs (7).…”

Section: Indirect Photoreduction Of Go With Acetone/2-prohmentioning

confidence: 99%

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High quality reduced graphene oxide flakes by fast kinetically controlled and clean indirect UV-induced radical reduction

et al. 2016

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This work highlights a surprisingly simple and kinetically controlled highly efficient indirect method for the production of high quality reduced graphene oxide (rGO) flakes via UV irradiation of aqueous dispersions of graphene oxide (GO), in which the GO is not excited directly. While the direct photoexcitation of aqueous GO (when GO is the only light-absorbing component) takes several hours of reaction time at ambient temperature (4 h) leading only to a partial GO reduction, the addition of small amounts of isopropanol and acetone (2% and 1%) leads to a dramatically shortened reaction time by more than two orders of magnitude (2 min) and a very efficient and soft reduction of graphene oxide. This method avoids the formation of non-volatile species and in turn contamination of the produced rGO and it is based on the highly efficient generation of reducing carbon centered isopropanol radicals via the reaction of triplet acetone with isopropanol. While the direct photolysis of GO dispersions easily leads to degradation of the carbon lattice of GO and thus to a relatively low electric conductivity of the films of flakes, our indirect photoreduction of GO instead largely avoids the formation of defects, keeping the carbon lattice intact.Mechanisms of the direct and indirect photoreduction of GO have been elucidated and compared.Raman spectroscopy, XPS and conductivity measurements prove the efficiency of the indirect photoreduction in comparison with the state-of-the-art reduction method for GO (hydriodic acid/trifluoroacetic acid). The rapid reduction times and water solvent containing only small amounts of isopropanol and acetone may allow easy process up-scaling for technical applications and low-energy consumption.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%