Isopropyl-9H-thioxanthen-9-one, mixture of 2- and 4-isomers

Isopropylthioxanthone(ITX) is a thioxanthone derivative widely utilized as a photoinitiator in polymerization processes. It is available as a mixture of 2- and 4- isomers. It breaks down into free radicals upon exposure to ultraviolet radiation, initiating polymerization in UV curing inks, wood coatings, paper coatings, optical fiber, screen printing, and paper varnish.

Isopropylthioxanthone can be used as:

• A photoinitiator along with azolium tetraphenylborate to N-heterocyclic carbene (NHC) generation in the synthesis of polyurethane, polyester, and ROMP (ring-opening metathesis polymerization) polymers. The mixture of ITX and azolium tetraphenylborate serves as an air-stable NHC photogenerator, activated by irradiation at 365 nm.
• A photocatalyst to facilitate the functionalization of bicyclo[1.1.0]butanes. This approach allows for the introduction of various functional groups onto the bicyclo[1.1.0]butane framework.
• A sensitizer that absorbs light and transfers energy to di(tert-butylphenyl)iodonium salts, facilitating their photolysis. This process generates reactive species necessary for initiating polymerization reactions. This sensitization approach is useful in various fields, including coatings, adhesives, and dental materials, where controlled polymerization is essential.