vinüülhalogeniid

Vinyl halide is a chemical compound that contains a halogen atom bonded to a carbon atom involved in a carbon-carbon double bond. The general formula for vinyl halides is CH2=CHX, where X represents a halogen atom such as chlorine (Cl), bromine (Br), or iodine (I). Fluorine can also be present, forming vinyl fluoride. These compounds are also known as haloalkenes.

The presence of the double bond significantly influences the chemical reactivity of vinyl halides compared to their saturated counterparts, alkyl halides. The pi electrons in the double bond make the carbon atoms more electron-rich. However, the electronegativity of the halogen atom withdraws electron density, leading to a complex electronic environment. This structure makes them less susceptible to typical nucleophilic substitution reactions that readily occur with alkyl halides. Instead, they often undergo addition reactions across the double bond or participate in polymerization processes.

Vinyl chloride is perhaps the most well-known example and is a crucial monomer in the production of polyvinyl chloride (PVC), a widely used plastic. Vinyl bromide and vinyl fluoride also have industrial applications, though often in more specialized areas. The synthesis of vinyl halides can be achieved through various methods, including the dehydrohalogenation of vicinal dihalides or the halogenation of alkynes. Their environmental persistence and potential toxicity are factors that are considered in their industrial use and regulation.