Aryl tosylates as non-ionic photoacid generators (PAGs): photochemistry and applications in cationic photopolymerizations

Torti, Edoardo; Giustina, Gioia Della; Protti, Stefano; Merli, Daniele; Brusatin, Giovanna; Fagnoni, Maurizio

doi:10.1039/c5ra03522h

Cited by 25 publications

(34 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This observation is compatible with the reaction of sulfonyl radical RSO 2 . with molecular oxygen to afford sulfonic acid (RSO 3 H, path d) via the peroxosulfonyl radical III , as already observed in previous studies [15, 21] …”

Section: Resultssupporting

confidence: 70%

“…Whereas the photoheterolysis of the Ar‐OX bond occurs exclusively in aryl phosphates bearing electron‐rich substituents in polar media, [12] a more complex situation was reported in the case of aryl sulfonates, since the photohomolysis of the ArO−S bond (e.g. in aryl nonaflates, [13] imidazylates [14] or tosylates [15] ) was the preferred path. On the other hand, in most cases triplet sensitization diverts the photoreactivity towards an aryl cation chemistry [12a–f, 16] …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates

Bonesi

Protti

Fagnoni

2021

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

The photochemical behaviour of selected aryl sulfonates and phosphates (ArOX) in polar and nonpolar media has been investigated by laser flash photolysis (LFP) experiments. Two main pathways have been identified, namely the photohomolysis of the ArO−X bond or the photoheterolysis of the Ar−OX bond depending on the nature of the leaving group (OX) and on the nature of the substituents on the aromatic ring. In nonpolar solvents the esters are quite photostable due to an efficient triplet deactivation. In polar solvents, the homolytic fragmentation of the ArO−S bond from the exited singlets was found in aryl sulfonates bearing moderately electron‐donating groups as well as electron‐withdrawing groups. In electron‐rich aryl phosphates and sulfonates photoheterolysis of the Ar−OP/Ar−OS bond took place as the exclusive pathway.

show abstract

Section: Resultssupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates

Bonesi

Protti

Fagnoni

2021

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Compound 3 was synthesized following a known procedure . To a solution of 4′‐hydroxyacetophenone (2.72 g, 20 mmol) and triethylamine (15 mL, 108 mmol) in dichloromethane (80 mL), p ‐toluenesulfonyl chloride (4.58 g, 24 mmol) was added portion wise at room temperature.…”

Section: Methodssupporting

confidence: 61%

“…As a final test, in order to have even more insights on the role of 1 in the process, we repeated the polymerization experiments on a GB film in the presence of the fluorine‐free, electron‐poor tosylate 3 as photoacid generator (Figure ). Compound 3 was chosen in reason of the reducibility comparable to 1 (E 1/2 CAT =−1.60 V vs. Ag/AgCl, 3 M NaCl) and of the good results it showed as PAG for UV photopolymerization of epoxy‐based hybrid organic‐inorganic materials . However, no substantial differences between the degrees of polymerization reached by the tested film and its blank (not containing 3 ) were observed (see Supporting Information, Figure S6).…”

Section: Resultsmentioning

confidence: 99%

Aryl Sulfonates as Initiators for Extreme Ultraviolet Lithography: Applications in Epoxy‐Based Hybrid Materials

et al. 2018

Self Cite

View full text Add to dashboard Cite

Two perfluoroaryl sulfonates were tested as initiators for the extreme ultraviolet (EUV)-promoted polymerization of silicabased hybrid organic-inorganic films containing epoxy moieties. One of the sulfonates was able to strongly improve the polymerization efficiency in the tested materials and behaved much better than the commercial photoacid generator diphenylsulfonium (4-phenylthiophenyl)diphenylsulfonium triflate. Furthermore, lithographic patterns with sub-micrometric reso-lutions were achieved by irradiating resists containing the selected sulfonate (1 % molar concentration) at very low EUV doses (about 10 mJ cm À2 ). The proposed combination of specifically designed perfluoroaryl sulfonates and hybrid organic-inorganic materials is a starting point to develop highperformance and cost-effective EUV-sensitive resists for the microelectronic industry.[a] Dr. CAT = À1.60 V and À1.50 V vs. Ag/AgCl, 3 M NaCl, respectively), thus potentially suitable for EUVL.

show abstract

“…Then, the latter traps a proton in the media to give the expected sulfonic acid (Scheme , pathway A). According to the same authors, other sulfonates such as aryl tosylates dissociate preferentially through homolytic cleavage under irradiation between the ArO−S bond to generate the sulfonyl radical that further reacts with the dissolved oxygen in the solution. Then, the evolution of this radical leads to the corresponding sulfonic acid (Scheme , pathway B).…”

Section: Photoacid Generatorsmentioning

confidence: 99%

Recent Advances and Challenges in the Design of Organic Photoacid and Photobase Generators for Polymerizations

et al. 2019

View full text Add to dashboard Cite

Photopolymerization, or the use of light to trigger polymerization, is one of the most exciting technologies for advanced manufacturing of polymers. One of the key components in the photopolymerization processes is the photoactive compound that absorbs the light, generating the active species that promotes the polymerization and largely determines the final properties of the material. The field of photopolymerization has been dominated by photoradical generators to mediate radical reactions. In the last decade, to expand the number of polymers that can be prepared by photopolymerization, intensive research has been devoted to the synthesis and utilization of photoactive molecules that are able to generate a base or an acid upon irradiation. These organic compounds are known to promote not only the ring‐opening polymerization of various heterocyclic monomers such as lactones, carbonates, or epoxides but also to trigger the step‐growth synthesis of polyurethanes. This Minireview highlights the recent advances in the development of organic photobase and photoacid generators, with the aim of encouraging the wider application of these photoactive compounds in the photopolymerization area and to expand the use of these polymers in advanced manufacturing processes.

show abstract

Aryl tosylates as non-ionic photoacid generators (PAGs): photochemistry and applications in cationic photopolymerizations

Abstract: Irradiation of aryl tosylates leads to homolysis of the ArO–S bond and PTSA or p-toluenesulfinic acid was released. The aryl sulfonates tested were then used as non-ionic photoacid generators (PAGs) in hybrid organic/inorganic sol–gel photoresists.

Cited by 25 publications

References 48 publications

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates

Aryl Sulfonates as Initiators for Extreme Ultraviolet Lithography: Applications in Epoxy‐Based Hybrid Materials

Recent Advances and Challenges in the Design of Organic Photoacid and Photobase Generators for Polymerizations

Contact Info

Product

Resources

About