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

Aromatic Hydrocarbon Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

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...
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

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.
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry01:29

Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry

Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.

You might also read

Related Articles

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

Sort by
Same author

Spatial transcriptome revealed associated biomarkers for endocrine therapy response in HR-positive/HER2-negative early breast cancer.

Chinese journal of cancer research = Chung-kuo yen cheng yen chiu·2026
Same author

Wafer-scale growth of highly stable p-type semiconducting monolayer MoSi<sub>2</sub>N<sub>4</sub> single crystals.

Nature materials·2026
Same author

Biomarkers for Pediatric Acute Respiratory Distress Syndrome: A Systematic Review.

Journal of inflammation research·2026
Same author

Capillary ratchets activated by interfacial flows for versatile torque generation and microassembly.

Science advances·2026
Same author

Real-World Analysis of Organ Transplantation-Specific Agent Based on Large Language Model in Post-Transplant Self-Management During Off-Hours: A Mixed-Methods Study.

Current medical science·2026
Same author

Gradient-guided layerwise adaptive noise injection for pre-trained language model fine-tuning.

Scientific reports·2026

Related Experiment Video

Updated: May 31, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
06:55

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Engineering Triplet Formation versus Symmetry-Breaking Charge Separation in Shape-Persistent Perylene Diimide

Yuanyuan Guo1, Shaohong Wang2, Tianrui Zheng1

  • 1State Key Laboratory of Information Photonic and Optical Communications and School of Physical Science and Technology, Beijing University of Posts and Telecommunications, Beijing 102206, China.

JACS Au
|May 29, 2026
PubMed
Summary

Researchers developed shape-persistent PDI macrocycles that control excited-state deactivation. These materials switch between intersystem crossing and charge separation pathways based on solvent polarity, advancing optoelectronic applications.

Keywords:
Intersystem crossingSolvent polarityortho-alkynyl substitutionshape-persistent macrocyclessymmetry-breaking charge separation

More Related Videos

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
06:35

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Related Experiment Videos

Last Updated: May 31, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
06:55

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
06:35

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Area of Science:

  • Materials Science
  • Photochemistry
  • Organic Electronics

Background:

  • Controlling excited-state deactivation in multichromophoric systems is crucial for optoelectronic materials.
  • Shape-persistent macrocycles offer rigidity but can weaken electronic coupling, posing a challenge for deactivation pathway control.

Purpose of the Study:

  • To design and investigate novel shape-persistent PDI macrocycles with tunable deactivation pathways.
  • To explore the influence of solvent polarity on excited-state dynamics in these PDI macrocycles.

Main Methods:

  • Synthesis of ortho-alkynyl-linked PDI macrocycles (Dimer and Trimer).
  • Transient absorption spectroscopy to probe excited-state dynamics.
  • Quantum chemical calculations to elucidate deactivation mechanisms.

Main Results:

  • PDI macrocycles exhibit solvent-polarity-controlled switching between intersystem crossing (ISC) and symmetry-breaking charge separation (SB-CS).
  • In nonpolar solvents, ortho-alkynyl substitution enhances ISC, with triplet yields increasing from Dimer (~65%) to Trimer (~85%).
  • In polar solvents, ultrafast SB-CS on a picosecond timescale outcompetes triplet formation.

Conclusions:

  • Rigid, weakly coupled molecular constructs enable precise control over triplet generation and SB-CS.
  • These PDI macrocycles demonstrate potential for advanced optoelectronic devices by managing excited-state deactivation pathways.