Halogenated hydrocarbons are compounds formed when hydrogen atoms in a hydrocarbon molecule are replaced by halogen atoms (fluorine, chlorine, bromine, iodine). Based on the type of substituted halogen and the structure of the hydrocarbon group, common types and representative compounds are as follows:
Classification by type of substituted halogen:
Chlorinated hydrocarbons
Chlorinated hydrocarbons are the most common class of halogenated hydrocarbons, referring to compounds formed when hydrogen atoms are replaced by chlorine. They have the widest industrial applications.
Common representatives include:
Saturated chloroalkanes: Chloromethane (CH₃Cl), dichloromethane (CH₂Cl₂), chloroform (CHCl₃, trichloromethane), carbon tetrachloride (CCl₄), chloroethane (C₂H₅Cl)
Unsaturated chloroalkenes: Vinyl chloride (C₂H₃Cl, polyvinyl chloride monomer), trichloroethylene (C₂HCl₃)
Fluorinated hydrocarbons:
Compounds formed by replacing hydrogen atoms with fluorine, commonly used in refrigerants and blowing agents. Common examples include Freons (such as dichlorodifluoromethane, CFC-12, which was once widely used as a refrigerant).
Brominated hydrocarbons:
Compounds formed by replacing hydrogen atoms with bromine. Common examples include bromomethane (CH₃Br), bromoethane (CH₃CH₂Br), and dibromoethane.