Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Halogens03:01

Halogens

23.6K
Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. Astatine is a highly unstable radioactive element, so currently, most of its properties are unknown due to its short half-life. Tennessine is a synthetic element also predicted to be in this group. 
23.6K
Halogenation of Alkenes02:46

Halogenation of Alkenes

18.9K
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.
18.9K
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

3.8K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
3.8K
Aromatic Hydrocarbon Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

3.8K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
3.8K
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions01:20

Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions

2.5K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.5K
Radical Halogenation: Thermodynamics01:34

Radical Halogenation: Thermodynamics

4.6K
The thermodynamic favorability of a reaction is determined by the change in Gibbs free energy (ΔG). ΔG has two components- enthalpy (ΔH) and entropy (ΔS). The entropy component is negligible for alkane halogenation because the number of reactants and product molecules are equal. In this case, the ΔG is governed only by the enthalpy component. The most crucial factor that determines ΔH is the strength of the bonds. ΔH can be determined by comparing the energy...
4.6K

You might also read

Related Articles

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

Sort by
Same author

TBT in California coastal waters: Monitoring and assessment.

Environmental monitoring and assessment·2013
Same author

The Mussel Watch concept.

Environmental monitoring and assessment·2013
Same author

Information needs for marine pollution studies.

Environmental monitoring and assessment·2013
Same author

Notes. Impact of fossil fuel combustion on sediments of Lake Michigan: a reprise.

Environmental science & technology·2012
Same author

U.S. "Mussel Watch" 1976-1978: an overview of the trace-metal, DDE, PCB, hydrocarbon and artificial radionuclide data.

Environmental science & technology·2012
Same author

Impact of fossil fuel combustion on the sediments of Lake Michigan.

Environmental science & technology·2012

Related Experiment Video

Updated: Feb 8, 2026

In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells
04:56

In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells

Published on: October 23, 2018

7.1K

Halogenated hydrocarbons: past, present and near-future problems.

E D Goldberg1

  • 1Scripps Institution of Oceanography, La Jolla, CA 92093.

The Science of the Total Environment
|March 1, 1991
PubMed
Summary

Early concerns about biocides endangering ecosystems have led to regulations. Current focus is on pesticide use in the tropics and Southern Hemisphere, with an International Mussel Watch Program proposed to assess environmental damage.

More Related Videos

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
06:44

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

Published on: March 24, 2018

69.6K
On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes
07:49

On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes

Published on: August 5, 2016

11.2K

Related Experiment Videos

Last Updated: Feb 8, 2026

In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells
04:56

In Vitro Method to Control Concentrations of Halogenated Gases in Cultured Alveolar Epithelial Cells

Published on: October 23, 2018

7.1K
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
06:44

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

Published on: March 24, 2018

69.6K
On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes
07:49

On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes

Published on: August 5, 2016

11.2K

Area of Science:

  • Environmental Science
  • Ecotoxicology
  • Marine Biology

Background:

  • Concerns regarding biocide environmental impact emerged in the 1940s.
  • Observed declines in seabird and marine mammal populations, alongside laboratory findings, prompted regulations on pesticides and polychlorinated biphenyls.
  • Current focus is on increased biocide usage in tropical and Southern Hemisphere regions, termed the "continental tilt".

Purpose of the Study:

  • To address the growing concern over pesticide and biocide contamination in the environment.
  • To propose an International Mussel Watch Program to monitor ecosystem health.
  • To identify future challenges in environmental toxin assessment and impact analysis.

Main Methods:

  • Historical review of scientific concerns and regulatory responses to biocides.
  • Observation of population declines in marine wildlife.
  • Laboratory experiments demonstrating toxic effects of pesticides on organisms.

Main Results:

  • Bans and strong regulations on pesticides and polychlorinated biphenyls were implemented by many nations.
  • An "International Mussel Watch Program" has been proposed for the tropics and Southern Hemisphere.
  • Future challenges include identifying unknown anthropogenic toxins, understanding toxin interactions, and assessing biocide impacts on mariculture.

Conclusions:

  • The long-standing concern over biocides necessitates ongoing monitoring and assessment programs.
  • The proposed International Mussel Watch Program is crucial for evaluating ecosystem health in vulnerable regions.
  • Addressing future challenges in toxin identification and impact assessment is vital for environmental protection.