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

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.2K
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...
1.2K
NMR Spectroscopy of Aromatic Compounds01:14

NMR Spectroscopy of Aromatic Compounds

4.7K
Aromatic compounds can be identified or analyzed using proton NMR and carbon‐13 NMR. Typically, aromatic hydrogens or hydrogens directly bonded to the aromatic rings are strongly deshielded by the aromatic ring current. Therefore, they absorb in the range of 6.5–8.0 ppm in proton NMR spectra. For instance, aromatic hydrogens directly bonded to the benzene ring absorb at 7.3 ppm. However, aromatic hydrogens of larger rings absorb farther upfield or downfield than the ideal range.
4.7K
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

1.7K
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...
1.7K
π Electron Effects on Chemical Shift: Overview01:27

π Electron Effects on Chemical Shift: Overview

1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

2.8K
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...
2.8K
Basicity of Heterocyclic Aromatic Amines01:25

Basicity of Heterocyclic Aromatic Amines

5.9K
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
5.9K

You might also read

Related Articles

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

Sort by
Same author

Metastructure Analysis of Self-Assembled Nanocubes with Different Equatorial Methyl Groups Based on Molecular Dynamics Simulations.

The journal of physical chemistry. B·2026
Same author

Bridging interpretable machine learning and large language models through direct representative selection and prediction: a two-layer framework for quantitative-linguistic insight.

Physical chemistry chemical physics : PCCP·2026
Same author

A theoretical study of molecular positron binding based on a correlation-polarization potential approach combined with position-dependent dielectric density functional theory.

The Journal of chemical physics·2026
Same author

Origin of heteroatom substitution effects on hyperfine coupling in muoniated radicals: A path-integral molecular dynamics study.

The Journal of chemical physics·2026
Same author

Room-Temperature Bicontinuous Cubic Phase Formed by Eutectic Mixtures Showing a Strong Adhesive Property.

Langmuir : the ACS journal of surfaces and colloids·2026
Same author

Microscopic origin of quantum plasticity in small H<sub>3</sub><sup>+</sup>(H<sub>2</sub>)<sub><i>n</i></sub> (<i>n</i> = 1-3) clusters revealed by path integral molecular dynamics simulations.

Physical chemistry chemical physics : PCCP·2026

Related Experiment Video

Updated: Jun 21, 2025

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.2K

Nuclear quantum and H/D isotope effects on aromaticity: path integral molecular dynamics study.

Hikaru Tanaka1, Kazuaki Kuwahata2, Masanori Tachikawa2

  • 1Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan. udagawa.taro.f1@f.gifu-u.ac.jp.

Physical Chemistry Chemical Physics : PCCP
|July 12, 2024
PubMed
Summary

Nuclear quantum effects (NQEs) significantly impact benzene's aromaticity by influencing both C-H and C-C bonds. These quantum fluctuations, particularly from carbon atoms, decrease aromaticity, altering vibrational modes.

More Related Videos

Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function
05:57

Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function

Published on: April 26, 2024

359
Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
08:54

Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid

Published on: January 25, 2020

5.7K

Related Experiment Videos

Last Updated: Jun 21, 2025

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.2K
Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function
05:57

Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function

Published on: April 26, 2024

359
Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
08:54

Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid

Published on: January 25, 2020

5.7K

Area of Science:

  • Organic Chemistry
  • Quantum Chemistry
  • Computational Chemistry

Background:

  • Aromaticity is a fundamental concept in organic chemistry, extensively studied through theoretical and experimental methods.
  • Previous theoretical studies primarily focused on the aromaticity of static molecular structures.
  • The role of dynamic effects like nuclear quantum effects (NQEs) and thermal fluctuations on aromaticity remained less explored.

Purpose of the Study:

  • To investigate the influence of nuclear quantum fluctuation (NQEs) and thermal fluctuation on the aromaticity of benzene.
  • To analyze how NQEs affect molecular bonds and overall aromaticity in benzene.
  • To understand the specific contributions of atomic vibrations to changes in aromaticity.

Main Methods:

  • Path Integral Molecular Dynamics (PIMD) simulations were employed to model benzene.
  • The study analyzed the impact of NQEs and thermal fluctuations on molecular structure and dynamics.
  • Housmer-DingeNomen (HOMA) and Nuclear Independent Chemical Shift (NICS) calculations were used to quantify aromaticity.

Main Results:

  • PIMD simulations revealed that NQEs significantly affect both carbon-hydrogen (C-H) and carbon-carbon (C-C) bonds in benzene.
  • HOMA and NICS calculations indicated a decrease in benzene's aromaticity due to NQEs.
  • The reduction in aromaticity was attributed to increased contributions from specific vibrational modes correlated with aromaticity.

Conclusions:

  • Nuclear quantum effects play a crucial role in modulating the aromaticity of benzene, extending beyond simple bond effects.
  • The dynamic nature of atoms, particularly carbon, under quantum fluctuations influences the electronic structure and aromaticity.
  • This study highlights the importance of considering quantum dynamics in theoretical assessments of aromaticity in organic molecules.