Halogenation of alkenes is the reaction in which a double bond is broken and replaced by a vicinal dihalide – 2 halogen atoms added to neighboring carbons. Alkenes and halogens are nonpolar molecules. A halogen molecule, for example Br 2, approaches a double bond of the alkene, electrons in the double bond repel electrons in the bromine molecule causing polarization of the halogen-halogen bond. Introduction. Halogenation of an alkane produces a hydrocarbon derivative in which one or more halogen atoms have been substituted for hydrogen atoms. Halogenation of Alkenes – Organic Chemistry Reaction Mechanism. This reaction follows a pattern of anti addition. Free radical halogenation therefore provides a method by which alkanescan be functionalized. The halides add to neighboring carbons from opposite faces of the molecule. https://www.khanacademy.org/.../alkene-reactions-tutorial/v/halogenation Alkanes are notoriously unreactive compounds because they are non-polar and lack functional groups at which reactions can take place. This creates a dipole moment in the halogen-halogen bond. The goal of this video is to help you understand rather than memorize concepts related to the halogenation mechanism. Reaction Overview: The alkene halogenation reaction, specifically bromination or chlorination, is one in which a dihalide such as Cl2 or Br2 is added to a molecule after breaking the carbon to carbon double bond. Mechanism and stereochemistry of halogenation. A severe limitation of radical halogenation however is the number of similar C-H bonds that are present in all but the simplest alkane… However, both types of molecules, under proper conditions, can undergo induced‐dipole formation, which leads to the generation of forces of attraction between the molecules.