Efficient Photoacids Based upon Triarylamine Dialkylsulfonium Salts

Abstract

New triarylamine dialkylsulfonium salts that are photosensitive in the near-ultraviolet have been prepared. The quantum yields of photoacid generation were found to be approximately 0.5 and are independent of the counterion. On the other hand, the efficiencies of the sulfonium salts toward the photopolymerization of cyclohexene oxide depend on the counterion and the sulfonium substituents. Photopolymerization kinetic studies demonstrate that these triphenylamine sulfonium salts are highly efficient cationic photoinitiators.

One/two-photon cationic polymerization in visible and near infrared ranges using two-branched sulfonium salts as efficient photoacid generators

“…1 and Table 1), and the absorption abilities of PAGs decrease after transforming sulfide groups into sulfonium salts. The corresponding frontier orbital is assigned to pes* transition because the pes* type transition exhibited smaller molar extinction coefficients (ε) than that of the pep* type transition [40]. This result was confirmed by DFT calculations (Fig.…”

“…To study these PAG as cationic photoinitiators, we replaced the initial counterion CF 3 SO 3 À by PF 6 À in accordance with an ion-exchanging method described in the reference. [40] Indeed, Zhou et al [40] clearly demonstrated that the cationic photopolymerization of epoxide resins leads to a more efficient epoxy ring-opening reaction with PF 6 À as counterion than with CF 3 SO 3 À . The details of characterization are provided in the electronic supporting information (ESIy).…”

“…Non-nucleophilic anions, such as PF 6 À , were exchanged to benefit the polymerization reactions [40] and obtain the two mono-branched sulfonium salt PAGs, namely, Mono-Para or Mono-Meta, as well as the two two-branched sulfonium salts are Bi-Para and Bi-Meta, with total yields (ca. 50%).…”

Sulfonium Boranes for the Selective Capture of Cyanide Ions in Water

“…[7] The resulting boron-centered chromophores are fluorescent and give rise to a broad emission band at 464 nm for [1] + (f = 0.02) and 450 nm for [2] + (f = 0.12) when excited at 350 and 340 nm in MeOH, respectively. As reported for other sulfonium salts, [8] [1] + and [2] + are sensitive to UV light and should therefore not be irradiated for extended periods of time. The crystal structures of these salts clearly show that: 1) the boron center adopts a trigonalplanar coordination geometry (S (C-B-C) = 359.68 for [1] + and 360.08 for [2] + ); 2) that the boron-sulfur separation in [1] + (3.07 ) is slightly shorter than in [2] + (3.12 ) (Figure 1).…”

Sulfonium Boranes for the Selective Capture of Cyanide Ions in Water

“…[7] The resulting boron-centered chromophores are fluorescent and give rise to a broad emission band at 464 nm for [1] + (f = 0.02) and 450 nm for [2] + (f = 0.12) when excited at 350 and 340 nm in MeOH, respectively. As reported for other sulfonium salts, [8] [1] + and [2] + are sensitive to UV light and should therefore not be irradiated for extended periods of time. The crystal structures of these salts clearly show that: 1) the boron center adopts a trigonalplanar coordination geometry (S (C-B-C) = 359.68 for [1] + and 360.08 for [2] + ); 2) that the boron-sulfur separation in [1] + (3.07 ) is slightly shorter than in [2] + (3.12 ) (Figure 1).…”