thioxanthen9one

Thioxanthen-9-one, also known as thioxanthone, is an organic compound with the chemical formula C13H8OS. It is a sulfur-containing analog of xanthen-9-one (xanthone), where the oxygen atom in the central ring is replaced by a sulfur atom. Thioxanthone is a pale yellow crystalline solid.

Thioxanthone and its derivatives are of interest due to their photochemical properties. They are known to act as photosensitizers, meaning they can absorb light energy and then transfer this energy to other molecules, initiating chemical reactions. This property makes them useful in various applications, particularly in photopolymerization and UV curing processes.

In photopolymerization, thioxanthone derivatives can initiate the cross-linking of monomers when exposed to UV light, leading to the formation of solid polymers. This is widely used in inks, coatings, adhesives, and dental materials. The efficiency of thioxanthone as a photoinitiator can be influenced by the substituents attached to its core structure.

Thioxanthone itself is not as commonly used as some of its substituted derivatives, such as 2-isopropylthioxanthone (ITX) or 2-chlorothioxanthone (CTX), which often exhibit enhanced solubility and reactivity in different formulations. Research continues to explore new thioxanthone derivatives with tailored properties for specific industrial and scientific applications. The synthesis of thioxanthone typically involves the cyclization of thiosalicylic acid derivatives.