photoinitiator

A photoinitiator is a chemical compound that absorbs electromagnetic radiation, such as light, to initiate or sustain a chemical reaction. These compounds are a type of initiator, which are substances that start a chain reaction by forming an intermediate compound capable of linking with many other molecules.12

Photoinitiators are commonly used in polymerization processes. When exposed to light, they generate reactive species, often free radicals, which then react with monomers to form polymers. This process is utilized in various applications, including the synthesis of materials like chloromethane from methane and chlorine, which is initiated by light.21