Photolyses of Diaryl α-Disulfones

Kobayashi, Michio; Tanaka, Kõji; Minato, Hiroshi

doi:10.1246/bcsj.45.2906

Cited by 29 publications

(10 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…44 Additionally, the desulfonylation of an arylsulfonyl radical has been proposed to rationalize some of the products formed in the photolyses of sulfonamide and sulfonate esters, 45 as well as diaryl R-disulfones. 46 Therefore, it is reasonable to conclude that SO 2 loss from the arylsulfonyl radicals is involved in the system currently under consideration.…”

Section: Resultsmentioning

confidence: 99%

Mechanism of Reaction and Photoacid Generation of N-Oxysuccinimidoarylsulfonate PAGs: A Laser Flash Photolytic Study

et al. 2001

View full text Add to dashboard Cite

The photochemical behavior of four N-oxysuccinimidoarylsulfonate photoacid generators (PAGs), 1-[[phenylsulfonyl]oxy]-(PSPD), 1-[[(4-methylphenyl)sulfonyl]oxy]-(MSPD), 1-[[(4-fluorophenyl)sulfonyl]oxy]-(FSPD), 1-[[ (4-chlorophenyl)sulfonyl]oxy]-2,5-pyrrolidinedione (CSPD), has been studied by means of nanosecond laser flash photolysis (λ exc ) 266 nm) and steady-state photolysis (λ exc ) 254 nm) with the aim of understanding the reaction mechanism and, particularly, photoacid generation pathways and efficiency in the deep UV region. Upon photoexcitation, the formation of arylsulfonyl radicals and their subsequent desulfonylation were detected for the four PAGs. In oxygen-saturated solution, the generation of the corresponding arylperoxy radicals was also observed. Photoacid generation quantum yields upon laser excitation were found to range from 0.04 to 0.05. Product studies following steady-state irradiations reveal that acid generation is dominated by the formation of sulfonic acids.

show abstract

Section: Resultsmentioning

confidence: 99%

Mechanism of Reaction and Photoacid Generation of N-Oxysuccinimidoarylsulfonate PAGs: A Laser Flash Photolytic Study

et al. 2001

View full text Add to dashboard Cite

show abstract

“…a S-S bond scission was proposed. 7 The absorption spectra observed in the flash photolysis of diphenyl disulfone is shown in Figure 7c.…”

Section: Methodsmentioning

confidence: 99%

Studies of sulfonyl radicals. 4. Flash photolysis of aromatic sulfones

Thoi¹,

Ito²,

Iino³

1978

J. Phys. Chem.

View full text Add to dashboard Cite

Although the values under method 1 do not pose serious problems, the £c2 value obtained by method 2 is quite small and is nearly half that of £H2-This anomaly should be due to the still remaining errors in the intensity ratios. In order to visualize this let us arbitrarily vary the intensities, very slightly, to fit the experimental ratio to the theoretical ratio. These approximated intensities along with their ratios and resultant £"2 values are given in Table IV under step 2. All £"2 values now are fairly satisfactory except for slightly lower value of fc2 in method 2, which is mainly due to the 1.68% error involved in the ratio of «6 (Table II).The correction added in the above step to r3 is only 0.005 m2/mol which falls within the experimental uncertainities. The correction to r5 is 0.074 m2/mol and is well beyond the experimental uncertainities. Hence the inequality of all four £a2 values given in Table IV is because the experimental isotopic intensity ratios are not found to be satisfactory.

show abstract

“…Changes in the a r e matic portion of HTA should accompany desulfonylation during preconsolidation. For example, aryl radicals resulting from loss of SO, can couple to give biphenyl-type structures (4,6,11,12) or substitute on an aromatic ring in the polymer backbone to give crosslinked structures. HTA is a random copolymer composed of the following repeat units ( 1):…”

Section: Pyrolysis/ Gas Chromatography/ M a S S Spectroscopymentioning

confidence: 99%

Processing of poly(ethersulfone)/graphite fiber composites: Thermooxidation, rheology, and consolidation

Brauman

Chow

1993

Polymer Composites

View full text Add to dashboard Cite

This study relates the formability of thermoplastic poly(ethersu1fone) HTA composites to thermooxidative history and rheological behavior. HTA/IM8 graphite fiber preforms were prepared under various temperature, time, and environmental (unbagged and vacuum-bagged) conditions, then consolidated into finished laminates under identical conditions. X-ray photoelectron spectroscopy and pyrolysis/gas chromatography/mass spectrometry were used to assess chemical degradation, and dynamic mechanical analysis (DMA) was used to evaluate Tg and rheological behavior in the finished laminates. All performing conditions resulted in some degradation of the HTA matrix, the presence of air being especially detrimental. The nature of this degradation is discussed and related to changes in Tg, melt viscosity of the matrix resin, and the extent of consolidation. A new DMA approach to evaluating degree of consolidation is developed and shown to offer considerable promise for quantitative assessment and ranking of composites.

show abstract

Photolyses of Diaryl α-Disulfones

Cited by 29 publications

References 12 publications

Mechanism of Reaction and Photoacid Generation of N-Oxysuccinimidoarylsulfonate PAGs: A Laser Flash Photolytic Study

Mechanism of Reaction and Photoacid Generation of N-Oxysuccinimidoarylsulfonate PAGs: A Laser Flash Photolytic Study

Studies of sulfonyl radicals. 4. Flash photolysis of aromatic sulfones

Processing of poly(ethersulfone)/graphite fiber composites: Thermooxidation, rheology, and consolidation

Contact Info

Product

Resources

About