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

¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
E1 Reaction: Stereochemistry and Regiochemistry02:43

E1 Reaction: Stereochemistry and Regiochemistry

One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.
Radical Reactivity: Concentration Effects01:20

Radical Reactivity: Concentration Effects

In a radical reaction, the concentration of starting materials governs the selectivity of a radical. For example, the reaction between an alkyl halide and an alkene, in the presence of tin hydride and AIBN, begins with the generation of a tin radical. The generated radical then abstracts halogen from the alkyl halide, producing an alkyl radical. This alkyl radical can either react with tin hydride, yielding an alkane, or add to an alkene, generating a nitrile-stabilized radical, eventually...
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule02:17

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
E2 Reaction: Stereochemistry and Regiochemistry02:43

E2 Reaction: Stereochemistry and Regiochemistry

Elimination reactions of alkyl halides can yield one or more alkenes depending on the specific regiochemical and stereochemical considerations. While the regiochemistry of the reaction governs the location of the double bond in the product, the stereochemical requirements often influence the geometry.
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major product and...
Factors Affecting α-Alkylation of Ketones: Choice of Base01:10

Factors Affecting α-Alkylation of Ketones: Choice of Base

α-Alkylation of ketones is achieved in the presence of alkyl halides and a base. The reaction proceeds via the formation of an enolate ion followed by nucleophilic substitution. The choice of base employed is essential as it is the key factor in determining the reaction outcome.
The reaction involving bases like EtO− whose conjugate acid EtOH (pKa = 15.9) is stronger than the ketone (pKa = 19.2) results in an equilibrium mixture with higher ketone concentration. As a consequence, side reactions...

You might also read

Related Articles

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

Sort by
Same author

Meibomian Gland Dysfunction and Dry Eye Disease in Mucous Membrane Pemphigoid Patients With and Without Ocular Complaints: A Comparative Study.

Ocular immunology and inflammation·2026
Same author

Corneal densitometry changes post-CXL for keratoconus: Comparative evaluation of epithelium-off, contact lens-assisted, and transepithelial techniques.

Indian journal of ophthalmology·2024
Same author

Evaluation of Meibomian Gland Structure and Function in Patients with Vernal Keratoconjunctivitis Using Non Contact Meibography and Lipid Layer Interferometry.

Ocular immunology and inflammation·2024
Same author

Ocular Cicatricial Pemphigoid in Young Patients.

Cornea·2024
Same author

Clinical outcomes of corneal neurotization using sural nerve graft in neurotrophic keratopathy.

PloS one·2023
Same author

Dead bag syndrome-in the capsular bag subluxated intraocular lens centration and refixation: A new technique.

Indian journal of ophthalmology·2023
Same journal

Erratum: Spectroscopy and Ground-State Transfer of Ultracold Bosonic ^{39}K^{133}Cs Molecules [Phys. Rev. Lett. 135, 203401 (2025)].

Physical review letters·2026
Same journal

Erratum: Lifetime of the ^{2}F_{7/2} Level in Yb^{+} for Spontaneous Emission of Electric Octupole Radiation [Phys. Rev. Lett. 127, 213001 (2021)].

Physical review letters·2026
Same journal

Laser-Plasma Based Seeded Free Electron Laser in the High-Gain Regime.

Physical review letters·2026
Same journal

Parent Hamiltonians for Stabilizer Quantum Many-Body Scars.

Physical review letters·2026
Same journal

Properties of Heavy Cosmic Nuclei Phosphorus, Chlorine, Argon, Potassium, and Calcium: Results from the Alpha Magnetic Spectrometer.

Physical review letters·2026
Same journal

Role of Spin-Isospin Symmetries in Nuclear β-Decays.

Physical review letters·2026
See all related articles

Related Experiment Video

Updated: Jun 18, 2026

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
10:07

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance

Published on: August 26, 2025

Finite range effects in (alpha, 2alpha) reactions.

Arun K Jain1, Bhushan N Joshi

  • 1Nuclear Physics Division, Bhabha Atomic Research Center, Mumbai-400 085, India. arunjain@barc.gov.in

Physical Review Letters
|November 13, 2009
PubMed
Summary
This summary is machine-generated.

Finite range calculations for alpha, 2alpha reactions resolve inconsistencies in nuclear physics. This study enhances understanding of alpha-alpha interactions and their short-distance behavior using nuclear radii and optical potentials.

More Related Videos

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry
08:23

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry

Published on: June 14, 2018

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

Related Experiment Videos

Last Updated: Jun 18, 2026

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
10:07

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance

Published on: August 26, 2025

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry
08:23

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry

Published on: June 14, 2018

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

Area of Science:

  • Nuclear Physics
  • Reaction Dynamics

Background:

  • Conventional zero-range analyses of (alpha, 2alpha) reactions exhibit significant inconsistencies.
  • Experimental observations of these reactions show energy-dependent variations up to 200 MeV.

Purpose of the Study:

  • To introduce finite range calculations for (alpha, 2alpha) reactions for the first time.
  • To resolve inconsistencies found in previous zero-range analyses.
  • To understand energy-dependent experimental data using established nuclear models.

Main Methods:

  • Performed finite range calculations for (alpha, 2alpha) reactions.
  • Utilized well-established nuclear radii and distorting optical potentials.
  • Analyzed energy-dependent experimental data up to 200 MeV.

Main Results:

  • Finite range calculations successfully removed inconsistencies from zero-range analyses.
  • The energy-dependent experimental observations were well-understood.
  • Results demonstrated sensitivity to the short-distance behavior of the alpha-alpha interaction.

Conclusions:

  • Knockout reactions are valuable probes of the knockout vertex at short distances.
  • The developed approach can be extended to atomic, molecular physics, and neutron multiplication calculations.
  • Finite range effects are crucial for accurate descriptions of nuclear reactions.