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

Stereoisomerism of Cyclic Compounds02:33

Stereoisomerism of Cyclic Compounds

9.3K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
9.3K
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.3K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.3K
Mesh Analysis01:20

Mesh Analysis

959
Mesh analysis is a valuable method for simplifying circuit analysis using mesh currents as key circuit variables. Unlike nodal analysis, which focuses on determining unknown voltages, mesh analysis applies Kirchhoff's voltage law (KVL) to find unknown currents within a circuit. This method is particularly convenient in reducing the number of simultaneous equations that need to be solved.
A fundamental concept in mesh analysis is the definition of meshes and mesh currents. A mesh is a closed...
959
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

2.1K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.1K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

3.3K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.3K

You might also read

Related Articles

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

Sort by
Same author

Planar tetracoordinate oxygen stabilized within triel-chalcogen dicationic frameworks.

RSC advances·2026
Same author

O©Li<sub>5</sub>F<sub>5</sub><sup>2-</sup>: A Global Minimum with a Planar Pentacoordinate Oxygen.

Inorganic chemistry·2026
Same author

Planar tetracoordinate nitrogen in main-group cationic clusters.

Physical chemistry chemical physics : PCCP·2026
Same author

From local to global or semilocal aromaticity: singlet-triplet switching in porphyrin tapes.

Chemical communications (Cambridge, England)·2026
Same author

A multi-task cross-attention strategy to segment and classify polyps.

Biomedical physics & engineering express·2025
Same author

Theoretical Prediction of a Stable Xenon Bis(diazaborolyl) Complex: A Donor-Acceptor Complex.

Inorganic chemistry·2025

Related Experiment Video

Updated: Sep 23, 2025

Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry
16:11

Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry

Published on: June 8, 2022

2.4K

Which NICS method is most consistent with ring current analysis? Assessment in simple monocycles.

R Báez-Grez1,2, Lina Ruiz3, R Pino-Rios2,4

  • 1Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andres Bello República 275 Santiago Chile.

RSC Advances
|May 11, 2022
PubMed
Summary
This summary is machine-generated.

This study introduces a straightforward NICS (nucleus-independent chemical shift) analysis method to accurately determine aromaticity in various chemical systems, including benzene and cyclooctatetraene (COT). This approach simplifies predicting aromatic or antiaromatic character.

More Related Videos

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

26.8K
X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells
10:16

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

Published on: August 20, 2019

14.0K

Related Experiment Videos

Last Updated: Sep 23, 2025

Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry
16:11

Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry

Published on: June 8, 2022

2.4K
Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

26.8K
X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells
10:16

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

Published on: August 20, 2019

14.0K

Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Aromaticity Studies

Background:

  • Aromaticity is a fundamental concept in chemistry, crucial for understanding molecular stability and reactivity.
  • Existing methods for assessing aromaticity can be complex, necessitating simpler and more reliable computational strategies.
  • Nucleus-independent chemical shift (NICS) is a widely used computational index for evaluating aromaticity.

Purpose of the Study:

  • To evaluate and compare different NICS-based strategies for analyzing the aromaticity of diverse chemical systems.
  • To identify the most effective and simplest NICS computational approach for predicting aromatic and antiaromatic character.
  • To correlate NICS component analysis with established methods like magnetically induced ring current densities.

Main Methods:

  • Performed nucleus-independent chemical shift (NICS) computations on representative aromatic and antiaromatic systems.
  • Analyzed the evolution of NICS components along the main molecular axis for each system.
  • Examined the contributions of sigma (σ) and pi (π) electrons to the out-of-plane NICS component (NICSz).

Main Results:

  • The analysis of NICS-component evolution along the main molecular axis proved to be the most adequate and simplest strategy.
  • This method successfully predicted the aromatic or antiaromatic character of benzene, Al42- cluster, cyclopropane, borazine, and planar cyclooctatetraene (COT).
  • The analysis of σ- and π-electron contributions to NICSz yielded results consistent with those obtained from ring current density analysis.

Conclusions:

  • A simplified NICS component analysis along the molecular axis is a robust and efficient method for assessing aromaticity.
  • This approach provides reliable predictions of aromatic and antiaromatic properties across various molecular structures.
  • The findings support the use of NICS component analysis as a valuable tool in computational aromaticity studies.