Thiophenium, tetrahydro-1-(4-methylphenyl)-, 1,1,1-trifluoromethanesulfonate (1:1), identified by CAS No. 2361264-45-9, is a specialized organic salt belonging to the class of aryl sulfonium salts. In industrial and research settings, this compound is primarily utilized as a high-performance Photoacid Generator (PAG). Its structure consists of a thiophenium cation substituted with a 4-methylphenyl (p-tolyl) group, balanced by a trifluoromethanesulfonate (triflate) anion.

Chemical Properties and Structure

The compound is characterized by its ionic nature, which grants it specific solubility and thermal profiles essential for precision manufacturing.

• Molecular Formula: [C11H15S]+ [CF3O3S]
• Cation: The tetrahydrothiophenium ring provides a cyclic sulfonium center, which is further stabilized by the electron-donating methyl group on the phenyl ring.
• Anion: The triflate (OTf) anion is a highly stable, non-nucleophilic group. It is the conjugate base of triflic acid, one of the strongest known organic acids.
• Stability: These salts are generally stable under ambient conditions but are designed to undergo photolysis (decomposition by light) when exposed to specific wavelengths, typically in the deep ultraviolet (DUV) range.

Functional Mechanism as a Photoacid Generator

The primary utility of CAS 2361264-45-9 lies in its ability to produce a strong acid upon irradiation. When the compound absorbs a photon, the bond between the sulfur atom and the aryl group undergoes cleavage, initiating a chemical sequence that releases trifluoromethanesulfonic acid (CF3SO3H).

This "photo-released" acid then acts as a catalyst for subsequent chemical reactions in the surrounding medium, a process vital for chemically amplified resists (CARs).

Industrial Applications

1. Semiconductor Lithography

The most significant application for this compound is in microlithography. In the fabrication of integrated circuits, it is added to photoresist formulations.

• Precision: Because the acid is only generated where light hits the wafer, it allows for the creation of extremely fine circuit patterns at the nanometer scale.
• Sensitivity: As a "chemically amplified" component, a single photon can trigger the release of an acid molecule that then catalyzes hundreds of subsequent reactions (such as deprotection of polymers), significantly increasing the speed and efficiency of the manufacturing process.

2. UV-Curable Coatings and Inks

In industrial coatings, this thiophenium salt serves as a cationic photoinitiator. It is used to trigger the polymerization of epoxies and vinyl ethers.

• Unlike traditional radical initiators, cationic polymerization initiated by sulfonium salts is not inhibited by oxygen, making it ideal for thin-film applications and high-speed printing inks.

3. Polymer Science

It is employed in research for the synthesis of complex polymer architectures where precise control over the start of a reaction is required. By using light as the "trigger," scientists can control the spatial and temporal aspects of polymerization.

Handling and Safety

As a professional-grade chemical intermediate:

• Light Sensitivity: The compound must be stored in light-shielded (amber) containers to prevent premature degradation.
• Corrosivity: While the salt itself is stable, the acid generated upon exposure to light or moisture is highly corrosive. Standard laboratory PPE (gloves, goggles) and fume hoods are required for handling.
• Thermal Decomposition: Exposure to high temperatures may release toxic fumes, including sulfur oxides (SOx) and hydrogen fluoride (HF).

Product:2361264-45-9,Semiconductor Photoresist, Electronic Chemicals