Photoreduction of benzophenone by amines, alcohols, and hydrocarbons.  Medium effects.  Photochemical oxidative deamination

Cohen, Saul G.; Baumgarten, Ronald J.

doi:10.1021/ja00990a020

Cited by 59 publications

(20 citation statements)

References 17 publications

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“…It is clearly seen that a maximum absorbance peak at about 290 nm, which is assigned to n−π* transition of BP moieties, continuously decreases as irradiation time progresses. Meanwhile, the absorbance intensity at λ < 240 nm, which is mainly assigned to benzopinacol, gradually increases as irradiation time progresses as well, which is well consistent with the reported hydrogen abstraction mechanism, − suggesting a conversion of BP to the benzopinacol moiety under irradiation. After irradiating for more than 10 min, the spectra remain the same, suggesting a complete conversion of BP.…”

Section: Resultssupporting

confidence: 86%

Light-Induced In Situ Chain Extension and Critical Gelation of Benzophenone End-Functionalized Telechelic Associative Polymers in Aqueous Solution

Guan

Luo

et al. 2021

Macromolecules

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Telechelic associative polymers (TAPs) can form a dynamic physical network in water and exhibit interesting solution viscoelastic behavior. In this work, we designed and prepared two benzophenone (BP) end-functionalized poly(ethylene glycol) TAPs (BPC n TAPs, n = 6, 10) by the efficient CuAAC click reaction of alkyne-modified BP and azide end-capped poly(ethylene glycol). BP moieties in the two TAPs can perform typical hydrogen abstraction reactions and consequent radical recombination under UV light irradiation in the core of micelles. Such a light-induced BP radical recombination has significant influence on the structure and solution dynamics of TAPs. When the polymer concentration exceeds the percolation concentration, only BPC10TAP can undergo in situ chain extension and even crosslinking reactions in the core of micelles under light irradiation by the self-assembly-assisted recombination strategy due to the slower escaping rate of stickers from micelles. Meanwhile, the association of extended chains (high-frequency plateau) coupling with the critical gelation behavior (low-frequency plateau) and a sol–gel transition were observed in the BPC10TAP solution also. The chain extension and consequent gelation behavior in bulk are usually based on the different reactivities of functional groups, whereas the present case is based on the topology of the dynamic network in consideration of only end-capped BP groups in the chain. This is the first report about such a chain extension and subsequent vulcanization-like critical gelation behavior of TAPs in aqueous solution. The work not only provides a new approach to understand the influence of chain topology on rheological behavior of TAP aqueous solution but also brings new insights into the sol–gel transition of TAPs.

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Section: Resultssupporting

confidence: 86%

Light-Induced In Situ Chain Extension and Critical Gelation of Benzophenone End-Functionalized Telechelic Associative Polymers in Aqueous Solution

Guan

Luo

et al. 2021

Macromolecules

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“…(ß) Initial H+ transfer is most improbable because although protons (HC10 4 )quench 1-cyanonaphthalenefluorescence(kq = 1.5 x 10 9 M-1 s- 1 ) at a rate comparable with k for NaBH 4 (k = 3.3 x 10 9 M -1 s-1 ), their concentration in the alkalineq conditions used is so low that they would be incapable of competing effectively with BH; for the excited species.…”

mentioning

confidence: 99%

The photoreduction of aromatic systems

Barltrop¹

1973

Pure and Applied Chemistry

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“…The photoreduction of benzophenone by the primary and secondary alkyl amines gave the imino compound in high yields. 11 The imines can be hydrolyzed to aldehydes and ketones, respectively, and will give 2,4-dinitrophenylhydrazone. Therefore, it is reasonable to consider that the red-brown residual syrup would be N-p-hydroxyethylidenemonoethanolamine hydroiodide.…”

Section: Resultsmentioning

confidence: 99%

Photopolymerization of Methyl Methacrylate Initiated by Iodine—Monoethanolamine

Sakai

Takahashi

Sakota

1974

Polym J

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The photopolymerization of methyl methacrylate (MMA) in the presence of iodine (h) and monoethanolamine (MEA) was investigated and compared with that of MMA photosensitized by 12-triethylamine. The kinetic data suggested that the photopolymerization of MMA with 12-MEA proceeded by a radical mechanism. The composition curve of the photosensitized copolymerization of MMA and styrene with h-MEA also supported the radical mechanism. The ultraviolet spectrum of h and MEA in dichloromethane solution showed a charge-transfer absorption band at 245 nm, and the absorbance near the maximum wavelength measured by the continuous variation method suggested the formation of a charge-transfer complex with a 1 : 1 molar ratio of h and MEA. It seems likely that monoethanolamine hydroiodide and N-p-hydroxyethylidenemonoethanolamine hydroiodide are formed by decomposition of the charge-transfer complex, and that photolysis of the latter yields a radical of diethanolamine which initiates the polymerization of MMA. Monoethanolamine hydroiodide was also found to have a photosensitizing effect for the polymerization of MMA • in an excess of monoethanolamine.

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Photoreduction of benzophenone by amines, alcohols, and hydrocarbons. Medium effects. Photochemical oxidative deamination

Cited by 59 publications

References 17 publications

Light-Induced In Situ Chain Extension and Critical Gelation of Benzophenone End-Functionalized Telechelic Associative Polymers in Aqueous Solution

Light-Induced In Situ Chain Extension and Critical Gelation of Benzophenone End-Functionalized Telechelic Associative Polymers in Aqueous Solution

The photoreduction of aromatic systems

Photopolymerization of Methyl Methacrylate Initiated by Iodine—Monoethanolamine

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