Thioxanthone

Thioxanthone

File:9H-thioxanthen-9-one 200.svg

Chemical structure of Thioxanthone

Thioxanthone is an organic compound that belongs to the class of heterocyclic compounds known as thioxanthenes. It is characterized by a tricyclic structure consisting of two benzene rings fused to a central thioxanthene moiety. Thioxanthone is primarily used as a photoinitiator in the polymerization of acrylates and other monomers.

Chemical Properties

Thioxanthone has the chemical formula C₁₃H₈OS and a molecular weight of 212.27 g/mol. It is a yellow crystalline solid that is sparingly soluble in water but soluble in organic solvents such as acetone and chloroform.

Structure

The structure of thioxanthone consists of a thioxanthene core with a carbonyl group (C=O) at the 9-position, giving it the name 9H-thioxanthen-9-one. This structure is responsible for its photochemical properties.

Applications

Thioxanthone is widely used in the printing and coating industries as a photoinitiator. It absorbs ultraviolet (UV) light and initiates the polymerization of monomers, leading to the formation of polymers. This property is utilized in the production of UV-curable inks, coatings, and adhesives.

Photoinitiation

In the presence of UV light, thioxanthone undergoes a photochemical reaction that generates radicals. These radicals initiate the polymerization process by reacting with monomers, leading to the formation of a polymer network. This process is fast and efficient, making thioxanthone a valuable component in UV-curable systems.

Safety and Handling

Thioxanthone should be handled with care, as it can cause skin and eye irritation. It is recommended to use appropriate personal protective equipment (PPE) such as gloves and goggles when handling this compound. In case of contact with skin or eyes, the affected area should be rinsed thoroughly with water.

Related Pages

• Thioxanthene
• Photoinitiator
• Polymerization
• UV-curable