Fluoroarylsulfonium photoacid generators
The present invention discloses a new class of triarylsulfonium salt photoacid generators (PAGs), which are thermally stable and can be activated by long wavelength UV or visible light. The sulfonium PAGs of the present invention are additionally soluble in monomers that can be polymerized by cationic polymerization chemistry, and mixtures of said sulfonium PAGs and monomers can be stored for long periods of time without undergoing polymerization. Furthermore, typical holographic recording media comprising one of these sulfonium PAGs, polymerizable monomer(s), a sensitizing dye, and a binder can be stored for long periods of time without exhibiting significant loss of recording sensitivity. Preferred sulfonium PAGs of the present invention are sulfonium PAGs substituted with one or more fluoro or fluoroalkyl groups.
1 . A sulfonium salt represented by the Structural Formula (I):
wherein Ar 1 is an aryl group substituted with one or more fluoroalkyl, fluoro or chloro groups and Ar 2 -Ar 3 are independently a substituted or unsubstituted aryl group, and Ar 4 -Ar 7 are independently substituted or unsubstituted aryl groups.
2 . The sulfonium salt of claim 1 wherein Ar 1 is an aryl group substituted with one or more fluoroalkyl or fluoro groups.
3 . The sulfonium salt of claim 2 wherein Ar 4 is substituted with one or more fluoro or fluoroalkyl groups.
4 . The sulfonium salt of claim 3 , wherein Ar 4 —Ar 7 are independently an aryl group substituted with one or more fluoro or fluoroalkyl groups.
5 . The sulfonium salt of claim 3 wherein Ar 1 is a phenyl group substituted with one or more fluoro or fluoroalkyl groups and Ar 4 is a phenyl group substituted with one or more fluoro or fluoroalkyl groups.
6 . The sulfonium salt of claim 5 , wherein Ar 1 is a phenyl group substituted with one or more perfluoroalkyl groups or is perfluorinated.
7 . The sulfonium salt of claim 6 , wherein Ar 4 -Ar 7 are independently a phenyl group substituted with one or more fluoro or fluoroalkyl groups.
8 . The sulfonium salt of claim 7 wherein Ar 4 -Ar 7 are independently perfluorinated or 3,5-bis(trifluoromethyl) substituted phenyl groups.
9 . The sulfonium salt of claim 8 wherein Ar 2 -Ar 3 are independently substituted or unsubstituted phenyl groups.
10 . The sulfonium salt of claim 9 wherein the phenyl group represented by Ar 1 is perfluorinated, 3-trifluoromethyl substituted or 3,5-bis(trifluoromethyl) substituted.
11 . A sulfonium salt represented by the Structural Formula (II):
wherein:
R 1 and R 2 are methyl; R 3 and R 5 -R 7 are —H; and R 4 is —CF 3 or —Cl;
R 1 -R 3 and R 5 -R 7 are —H; and R 4 is —CF 3 or —Cl;
R 1 and R 2 are —H or methyl; and R 3 -R 7 are —F;
R 1 and R 2 are methyl; R 3 , R 5 and R 7 are —H; and R 4 and R 6 are —CF 3 ; or
R 1 -R 3 , R 5 and R 7 are —H; and R 4 and R 6 are —CF 3 ; and
X − is represented by Structural Formula (III) or (IV):
12 - 60 . (canceled)