Triphenylsulfonium triflate
Encyclopedia
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
. The triphenylsulfonium salts absorb at 233 nm, which induces the series of reactions shown:
In a typical application, photoacids catalyze the polymerization of epoxide
s.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
[(C6H5)3S][CF3SO3]. This colourless salt consists of a sulfonium
Sulfonium
A sulfonium ion, also known as sulphonium ion or sulfanium ion, is a positively charged ion featuring three organic substituents attached to sulfur. They have the formula [SR3]+...
cation and the triflate
Triflate
Trifluoromethanesulfonate, also known by the trivial name triflate, is a functional group with the formula CF3SO3-. The triflate group is often represented by -OTf, as opposed to -Tf...
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
Photolithography
Photolithography is a process used in microfabrication to selectively remove parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate...
. The triphenylsulfonium salts absorb at 233 nm, which induces the series of reactions shown:
- [(C6H5)3S+][CF3SO3-] + hν → [(C6H5)2S+.][CF3SO3-] + C6H5.
- [(C6H5)2S+.][CF3SO3-] + C6H5. → (C6H5C6H4)(C6H5)S + CF3SO3H
In a typical application, photoacids catalyze the polymerization of epoxide
Epoxide
An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in...
s.