Related Experiment Video
Updated: Oct 26, 2025
05:34
Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
8.1K
Water Depletion Enhanced by Halogenation of Benzene
Satoshi Shibuta1, Hiroshi Imamura2, Kota Shibuta3
1Department of Physics, College of Humanities and Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-Ku, Tokyo 156-8550, Japan.
The Journal of Physical Chemistry. B
|August 2, 2021
Summary
Hydrophobic hydration volume changes depend on solute chemical properties, not just packing effects. Halogenated benzenes reveal that specific functional groups modulate water structure, impacting hydration volumes.
Area of Science:
- Physical Chemistry
- Solution Chemistry
- Solvation Dynamics
Background:
- The pressure dependence of hydrophobic solute solubility reflects volume changes during hydrophobic hydration.
- These volume changes are traditionally attributed to packing effects related to van der Waals volumes.
- However, solute chemical properties may also significantly influence hydration volumes.
Purpose of the Study:
- To investigate the role of solute chemical properties in hydrophobic hydration volume changes.
- To examine the hydration behavior of halogenated benzenes as model hydrophobic solutes.
- To differentiate between packing effects and chemical property contributions to hydration volumes.
Main Methods:
- Solution density measurements of benzene and its halogenated derivatives in aqueous solutions.
- Volumetric analysis to determine excess particle numbers and hydration volumes.
- Comparison of experimental data with established models for hydrophobic hydration.
Main Results:
- Benzene, fluorobenzene, and chlorobenzene exhibited negative hydration volumes.
- Bromobenzene and iodobenzene displayed positive hydration volumes.
- Volumetric analyses showed deviations from universal hydration lines for bromobenzene and iodobenzene, indicating chemical modulation.
Conclusions:
- Hydration volume changes are influenced by both packing effects and specific solute chemical properties.
- Bromo and iodo functional groups modulate the hydration structure, leading to water depletion.
- The study highlights the limitations of solely packing-based explanations for hydrophobic hydration.
Related Concept Videos
01:11Reactions at the Benzylic Position: Halogenation
3.0K
Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.
3.0K
01:15Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
9.5K
Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...
9.5K
02:41Formation of Halohydrin from Alkenes
13.7K
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.
13.7K
02:46Halogenation of Alkenes
16.9K
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.
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.
16.9K
01:10Hydrolysis of Chlorobenzene to Phenol: Dow Process
3.3K
Simple aryl halides do not react with nucleophiles under normal conditions. However, the reaction can proceed under drastic conditions involving high temperatures and high pressure to give the substituted products. For example, chlorobenzene is converted to phenol using aqueous sodium hydroxide at 350 °C under high pressure by the Dow process. The reaction follows an elimination-addition mechanism involving a benzyne intermediate. Here, the chloride ion is...
3.3K
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
6.7K
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
6.7K