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

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

973
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
973
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

948
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
948
Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

889
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
889
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

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

1.0K
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...
1.0K
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

879
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
879
Deactivation Processes: Jablonski Diagram01:25

Deactivation Processes: Jablonski Diagram

589
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
589

You might also read

Related Articles

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

Sort by
Same author

Negative Electronic Friction and Non-Markovianity in Nonequilibrium Quantum Systems.

Nano letters·2026
Same author

Unraveling Charge and Energy Transfer in a Singlet Fission Donor-Acceptor Complex: An <i>Ab Initio</i> Quantum Dynamical Study.

Journal of chemical theory and computation·2026
Same author

Unraveling Exciton Trap Dynamics and Nonradiative Loss Pathways in Quantum Dots via Atomistic Simulations.

ACS nano·2025
Same author

Role of Superlattice Phonons in Charge Localization Across Quantum Dot Arrays.

ACS nano·2025
Same author

Nonadiabatic Quantum Dynamics of Molecules Scattering from Metal Surfaces.

Journal of chemical theory and computation·2025
Same author

Role of the Radical Character in Singlet Fission: An Ab Initio and Quantum Chemical Topology Analysis.

The journal of physical chemistry. A·2024
Same journal

Real-Time Vibrational Spectroscopy Reveals an Inversion Transition State in the Photoisomerization of Phenylazoimidazole.

The journal of physical chemistry letters·2026
Same journal

Precursor-Directed Self-Assembly in Hydrothermal Carbon Nitride Nanostructures Revealed by Nano-FTIR.

The journal of physical chemistry letters·2026
Same journal

Correction to "Equation-of-Motion Block-Correlated Coupled Cluster Method for Excited Electronic States of Strongly Correlated Systems".

The journal of physical chemistry letters·2026
Same journal

Rationalizing Stacking-Dependent Charge Injection Dynamics in Radical-Based Organic Light-Emitting Diodes.

The journal of physical chemistry letters·2026
Same journal

Bottom-Up Formation of the Simplest Geminal Thiol─Methanedithiol (CH<sub>2</sub>(SH)<sub>2</sub>)─and the Methyl Hydrodisulfide (H<sub>3</sub>CSSH) Isomer in Interstellar Analogue Ices.

The journal of physical chemistry letters·2026
Same journal

Trion Mediated Sequential Charge Separation in Functionalized CsPbBr<sub>3</sub>/AgInS<sub>2</sub> Hybrid Nanocrystals.

The journal of physical chemistry letters·2026
See all related articles

Related Experiment Video

Updated: Jun 7, 2025

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
10:52

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

Published on: February 4, 2017

9.7K

Spin Mixing in Intramolecular Singlet Fission: A First-Principles-Based Quantum Dynamical Study.

R K Kathir1, Pedro B Coto2,3, Michael Thoss1

  • 1Institute of Physics, Albert-Ludwigs University Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.

The Journal of Physical Chemistry Letters
|November 11, 2024
PubMed
Summary
This summary is machine-generated.

Singlet fission in pentacene dimers shows spin dipole-dipole interactions significantly populate quintet states. Molecular arrangement impacts spin dynamics and timescales.

More Related Videos

High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy
08:55

High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy

Published on: October 9, 2020

5.5K
Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
08:03

Study of Protein Dynamics via Neutron Spin Echo Spectroscopy

Published on: April 13, 2022

2.0K

Related Experiment Videos

Last Updated: Jun 7, 2025

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
10:52

Direct Imaging of Laser-driven Ultrafast Molecular Rotation

Published on: February 4, 2017

9.7K
High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy
08:55

High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy

Published on: October 9, 2020

5.5K
Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
08:03

Study of Protein Dynamics via Neutron Spin Echo Spectroscopy

Published on: April 13, 2022

2.0K

Area of Science:

  • Quantum chemistry
  • Photophysics
  • Organic electronics

Background:

  • Intramolecular singlet fission (ISF) is a key process for enhancing solar cell efficiency.
  • Pentacene dimers are promising materials for ISF due to their electronic properties.
  • Understanding the spin dynamics of ISF is crucial for optimizing energy conversion.

Purpose of the Study:

  • To investigate the spin dynamics of triplet-pair states in pentacene dimers with varying linker positions.
  • To elucidate the role of spin dipole-dipole interactions in populating different spin manifolds.
  • To determine how molecular geometry influences ISF dynamics.

Main Methods:

  • First-principles calculations
  • Density matrix quantum dynamical approach
  • Theoretical modeling of spin interactions

Main Results:

  • Spin dipole-dipole interactions significantly populate the quintet spin manifold when singlet, triplet, and quintet states are quasi-degenerate.
  • Regioisomerism (ortho, meta, para) profoundly impacts spin-mixing dynamics.
  • Molecular arrangement affects the relative populations of spin states and the timescale of the process.

Conclusions:

  • The study reveals a complex interplay between spin states during ISF in pentacene dimers.
  • Geometric arrangement is a critical factor controlling spin dynamics and efficiency.
  • These findings provide insights for designing advanced materials for organic electronics.