Triphenylsulfonium triflate

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IUPACName=Triphenylsulfonium triflate
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Section1= Chembox Identifiers
CASNo=66003-78-9
PubChem=24874589
SMILES=C1=CC=C(C=C1)C(=O)C(=O)O
Section2= Chembox Properties
Formula=C₁₉H₁₅F₃O₃S₂
MolarMass=412.45 g/mol
Appearance= colourless solid
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Section3= Chembox Hazards
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Triphenylsulfonium triflate is the chemical compound with the formula [(C₆H₅)₃S] [CF₃SO₃] . This colourless salt consists of a sulfonium cation and the triflate anion. Many related salts are known including those with other noncoordinating anions and those with diverse substituents on the phenyl rings.

These compounds are "photoacids," releasing strong acids upon photolysis, which is useful in photolithography. [J. V. Crivello "The Discovery and Development of Onium Salt Cationic Photoinitiators" Journal of Polymer Science: Part A: Polymer Chemistry, 1999, Volume 37, pp. 4241–4254. DOI CCC 0887-624X/99/234241-14.] The triphenylsulfonium salts absorb at 233 nm, which induces the series of reactions shown: [W. D. Hinsberg, G. M. Wallraff "Lithographic Resists" Kirk-Othmer Encyclopedia of Chemical Technology, Wiley-VCH, Weinheim, 2001. (Published online: 17 June, 2005)]

: [(C₆H₅)₃S⁺] [CF₃SO₃^-] + "h"ν → [(C₆H₅)₂S^+.] [CF₃SO₃^- + C₆H₅^.: [(C₆H₅)₂S^+.] [CF₃SO₃^-] + C₆H₅^. → (C₆H₅C₆H₄)(C₆H₅)S + CF₃SO₃H

In a typical application, photoacids catalyze the polymerization of epoxides.

References