Potential photoacid generators based on oxime sulfonates

Abstract

The bis-oxime of acenaphthenequinone and the mono-oxime of benzil have been sulfonated by reaction with 4-methylbenzenesulfonyl chloride and propylsulfonyl chloride. The four sulfonated oximes were characterised by X-ray single-crystal structure determinations. Some photochemical decompositions were studied using a 6-W 254-nm immersion well lamp in dichloromethane. The 4-methylbenzenesulfonate bis-oxime of acenaphthenequinone and the 4-methylbenzenesulfonate mono-oxime of benzil both give 4-methylbenzenesulfonic acid upon irradiation but not 4-methylbenzenesulfinic acid. Fragmentation pathways are discussed. The possible use of these compounds as photoacid generators in polymer resists and the role of secondary reactions to liberate acid is discussed.

Photoinduced generation of carbocations enabled by the promotion of aromaticity

“…Toward this end, a cascade of photo-Brønsted acid generator 15–18,79–81 and o -1 was employed. When a mixture of o -1a and N -hydroxynaphthalimide triflate (NIT) 79–81 was illuminated in CD 3 CN at 313 nm, efficient formation of c -2a (90%) was observed after 2 h (Fig. 3C).…”

“…With the formation of carbocations realized, attempts were made to avoid the use of pre-existing external acids. Toward this end, a cascade of photo-Brønsted acid generator [15][16][17][18][79][80][81] and o-1 was employed. When a mixture of o-1a and N-hydroxynaphthalimide triflate (NIT) [79][80][81] was illuminated in CD 3 CN at 313 nm, efficient formation of c-2a (90%) was observed after 2 h (Fig.…”

Recent advances on visible light Thiophene-based photoinitiators of polymerization

“…[388][389][390] To date, oxime sulfonates have only been scarcely studied as PAGs due to the lack of absorption in the visible range. [391,392] In 2018, three thiophenebased oxime sulfonates were examined as visible light PAGs, differing by the substitution of the sulfonate groups (See Figure 40). Especially, the three PAGs were designed so that the production of photoacids was optimized.…”

Recent advances on visible light bodipys and related difluoroborane structures-based photoinitiating systems

“…photoacid generators (PAGs) and this family of compounds has been extensively studied in the literature [54,75,76,80,301,318,319,[330][331][332][333][334][335][336][337]. The first bodipy-based photoacid generators (PAG-1 and PAG-2) were proposed in 2020 by Zhang and coworkers (See Figure22) [338].…”