Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Halogenation of Alkenes

Halogenation of Alkenes

Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.

Alkyl Halides

Alkyl Halides

Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...

Electrophilic Addition to Alkynes: Hydrohalogenation

Electrophilic Addition to Alkynes: Hydrohalogenation

Electrophilic addition of hydrogen halides, HX (X = Cl, Br or I) to alkenes forms alkyl halides as per Markovnikov's rule, where the hydrogen gets added to the less substituted carbon of the double bond. Hydrohalogenation of alkynes takes place in a similar manner, with the first addition of HX forming a vinyl halide and the second giving a geminal dihalide.

Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride

Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride

Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...

Electrophilic Addition to Alkynes: Halogenation

Electrophilic Addition to Alkynes: Halogenation

Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.

Formation of Halohydrin from Alkenes

Formation of Halohydrin from Alkenes

An alkene, such as propene, reacts with bromine in the presence of water to yield a halohydrin. Halohydrins contain a halogen and a hydroxyl group attached to adjacent carbons. When the halogen is bromine, it is called a bromohydrin, while a chlorohydrin has chlorine as the halogen.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Cationic Size Mismatch Dictates Structural Topology and Magnetic Properties of Honeycomb-Derived Na<sub>0.5</sub><i>RE</i><sub>0.5</sub>Ni<sub>2</sub>TeO<sub>6</sub> (<i>RE</i> = La-Lu and Y).

Inorganic chemistry·2026

Same author

Probing the structure of complex hydrocarbon molecules with X-ray-induced Coulomb explosion imaging.

Physical chemistry chemical physics : PCCP·2026

Same author

Deletion of <i>flgL</i> in <i>Mesorhizobium ciceri</i> USDA 3378 weakened competitive nodulation ability by reducing flagellum formation, biofilm formation, and extracellular polysaccharide secretion.

Applied and environmental microbiology·2026

Same author

Inhibition of elastin degradation alleviates joint degeneration in aging mice, dogs, and human models.

Proceedings of the National Academy of Sciences of the United States of America·2026

Same author

Time-resolved Coulomb explosion imaging of a photochemical ring opening reaction.

Nature communications·2026

Same author

Exploring the dominant endophytic pleosporalean fungi in <i>Poaceae</i> plants: taxonomic novelties within the suborder <i>Massarineae</i>.

Mycology·2026

Search research articles

Related Experiment Video

Updated: Aug 11, 2025

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

Hydrogen migration in inner-shell ionized halogenated cyclic hydrocarbons.

Abdul Rahman Abid^1,2,3, Surjendu Bhattacharyya⁴, Anbu Selvam Venkatachalam⁴

¹J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA. abdul.abid@phys.au.pk.

Scientific Reports

|February 6, 2023

Summary

Brominated cyclic hydrocarbons fragment into CH3+ ions, requiring hydrogen migration that increases with molecular size. Sequential fragmentation pathways produce CHx+ ions, with trends explained by Coulomb explosion simulations.

More Related Videos

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Published on: March 29, 2016

Hydrogen Production and Utilization in a Membrane Reactor

Hydrogen Production and Utilization in a Membrane Reactor

Published on: March 10, 2023

Related Experiment Videos

Last Updated: Aug 11, 2025

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Published on: March 29, 2016

Hydrogen Production and Utilization in a Membrane Reactor

Hydrogen Production and Utilization in a Membrane Reactor

Published on: March 10, 2023

Area of Science:

Physical Chemistry
Chemical Physics
Molecular Dynamics

Background:

Inner-shell ionization of molecules provides insights into electronic structure and fragmentation dynamics.
Brominated cyclic hydrocarbons represent a class of molecules with potential for complex fragmentation pathways.
Previous studies on linear hydrocarbons have shown hydrogen migration, but less is known about cyclic analogues.

Purpose of the Study:

To investigate the fragmentation mechanisms of bromocyclopropane, bromocyclobutane, and bromocyclopentane following Br(3d) and C(1s) inner-shell ionization.
To elucidate the role of intramolecular hydrogen (proton) migration in the formation of CH3+ fragments.
To analyze the fragmentation pathways and energy distributions of resulting ions.

Main Methods:

Coincidence ion momentum imaging was employed to precisely measure the momenta of all fragment ions.
Analysis of fragment ion momentum correlations was used to identify three-body fragmentation channels.
Classical Coulomb explosion simulations were utilized to interpret experimental observations and trends.

Main Results:

A significant yield of CH3+ fragments was observed, indicating intramolecular hydrogen migration.
The yield of CH3+ fragments increased with the size of the cyclic hydrocarbon molecule.
CHx+ fragments (x=0-3) with more hydrogens were preferentially formed through sequential fragmentation.

Conclusions:

Intramolecular hydrogen migration is a key process in the fragmentation of brominated cyclic hydrocarbons, with its extent dependent on molecular size.
Fragmentation pathways for these molecules are often sequential, leading to a variety of CHx+ ions.
The observed kinetic energy releases and fragment kinetic energies align with predictions from Coulomb explosion simulations, validating the proposed fragmentation models.