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

Structure of Benzene: Molecular Orbital Model01:18

Structure of Benzene: Molecular Orbital Model

9.6K
According to the molecular orbital (MO) model, benzene has a planar structure with a regular hexagon of six sp2 hybridized carbons. As shown in Figure 1, each carbon is bonded to three other atoms with C–C–C and H–C–C bond angles of 120°. The C–H bond length is 109 pm, and the C–C bond length is 139 pm which is midway between the single bond length of sp3 hybridized carbons (154 pm) and sp2 hybridized carbons (133 pm).
9.6K
Structure of Benzene: Kekulé Model01:07

Structure of Benzene: Kekulé Model

9.5K
In 1865, August Kekule suggested the structure of benzene according to the structural theory of organic chemistry based on the three assertions—formula of benzene is C6H6, all the hydrogens of benzene are equivalent, and each carbon must have four bonds due to its tetravalency.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
9.5K
π Molecular Orbitals of 1,3-Butadiene01:24

π Molecular Orbitals of 1,3-Butadiene

9.4K
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
9.4K
Newman Projections02:06

Newman Projections

17.2K
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
17.2K
Conformations of Cyclohexane02:11

Conformations of Cyclohexane

12.8K
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
12.8K
Chair Conformation of Cyclohexane02:02

Chair Conformation of Cyclohexane

14.8K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
14.8K

You might also read

Related Articles

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

Sort by
Same author

The Importance of Molecular Size, Concentration, and Thermal Conditions in Enhancing Lignin Derivatives' Interactions with Skin-like Membranes: Implications for Cosmetic and Therapeutic Applications.

International journal of molecular sciences·2025
Same author

Nature of Charge Transfer Effects in Complexes of Dopamine Derivatives Adsorbed on Graphene-Type Nanostructures.

International journal of molecular sciences·2024
Same author

Theoretical insights into dopamine photochemistry adsorbed on graphene-type nanostructures.

Physical chemistry chemical physics : PCCP·2024
Same author

Gold vs. Silver Colloidal Nanoparticle Films for Optimized SERS Detection of Propranolol and Electrochemical-SERS Analyses.

Biosensors·2023
Same author

New insight into catechol photochemistry: the role of different monomer and dimer configurations in radiation-less decay of the S<sub>1</sub> electronic excited state.

Physical chemistry chemical physics : PCCP·2022
Same author

Dopamine Photochemical Behaviour under UV Irradiation.

International journal of molecular sciences·2022

Related Experiment Video

Updated: Aug 10, 2025

Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.1K

Intermolecular-Type Conical Intersections in Benzene Dimer.

Attila Bende1, Alex-Adrian Farcaş1

  • 1National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400283 Cluj-Napoca, Romania.

International Journal of Molecular Sciences
|February 11, 2023
PubMed
Summary

Benzene dimers exhibit closer stacking in excited states, forming favorable intermolecular conical intersections (CIs) for radiationless decay. These CIs involve deformed rings and weaker inter-monomer bonds, confirmed by advanced computational methods.

Keywords:
CASSCFTDDFTbenzene dimerintermolecular-type conical intersectionspin-flipped TDDFT

More Related Videos

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
10:44

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Published on: April 19, 2019

10.9K
Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

10.4K

Related Experiment Videos

Last Updated: Aug 10, 2025

Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.1K
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
10:44

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Published on: April 19, 2019

10.9K
Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
08:51

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

10.4K

Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Photochemistry

Background:

  • Understanding excited state dynamics is crucial for photochemistry.
  • Benzene dimer serves as a model system for pi-stacking interactions.
  • Conical intersections (CIs) are key to radiationless decay in excited molecules.

Purpose of the Study:

  • To investigate the equilibrium and conical intersection geometries of the benzene dimer in its electronic excited state.
  • To explore the role of intermolecular interactions in excited state dynamics.
  • To identify pathways for radiationless deactivation in the benzene dimer.

Main Methods:

  • Density Functional Theory (DFT), Time-Dependent DFT (TDDFT), and Spin-Flipped TDDFT (SF-TDDFT) were employed.
  • Multiconfigurational Complete Active Space Self-Consistent Field (CASSCF) method was used for validation.
  • Minimally augmented def2-TZVPP and 6-31G(d,p) basis sets were utilized.
  • Nudged Elastic Band (NEB) method mapped relaxation pathways.

Main Results:

  • Benzene dimer stacking distance decreases by ~0.5 Å in the first excited state due to stronger intermolecular interactions.
  • Intermolecular-type CIs were identified, characterized by planar ring deformations and weaker inter-monomer C-C bonds (1.6-1.8 Å).
  • These intermolecular CIs are energetically more favorable than those with only one deformed monomer and are accessible via NEB.
  • SF-TDDFT results for CI geometries were validated by CASSCF.
  • Radiationless deactivation pathways through these CIs were confirmed.

Conclusions:

  • The benzene dimer undergoes significant structural changes in the excited state, leading to closer stacking.
  • Intermolecular-type conical intersections provide efficient pathways for radiationless decay.
  • Computational methods like DFT and CASSCF are valuable for studying excited state dynamics and reaction pathways.